SURFACE
VEHICLE
RECOMMENDED
PRACTICE
Vehicle Application Layer — J1939-71 (through December 2001)
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®
Issued 1994-08
Revised 2003-12
Superseding J1939-71 AUG2002
REV.
DEC2003
J1939-71
Foreword
This document has also changed to comply with the SAE Technical Standards Board format. Definitions
have changed to Section 3 and Abbreviations to Section 4. All other section numbers have changed
accordingly. This series of SAE Recommended Practices has been developed by the SAE Truck and
Bus Control and Communications Network Subcommittee of the SAE Truck and Bus Electrical and
Electronics Committee. The objectives of the subcommittee are to develop information reports,
recommended practices, and standards concerned with the requirements design and usage of devices
which transmit electronic signals and control information among vehicle components. The usage of these
documents is not limited to truck and bus applications; other applications may be accommodated with
immediate support being provided for construction and agricultural equipment, and stationary power
systems. These documents are intended as a guide toward standard practice and are subject to change
as to keep pace with experience and technical advances.
New parameters and parameter groups are reviewed and discussed by the Subcommittee on a regular
basis. This document reflects all changes and additions approved and balloted through December 2001.
Vehicle Application Layer - J1939-71 (through December 2001)
Table Of Contents
1. Scope .......................................................................................................................................................... 22
2. References .................................................................................................................................................. 22
2.1. Applicable Documents ............................................................................................................................... 22
2.1.1. SAE Publications ........................................................................................................................................ 22
2.1.2. ISO Publications ......................................................................................................................................... 22
3. Definitions .................................................................................................................................................. 22
4. Abbreviations .............................................................................................................................................. 22
5. Technical Requirements ............................................................................................................................. 22
5.1. General Guidelines ..................................................................................................................................... 23
5.1.1. Signal Characterization ............................................................................................................................... 23
5.1.2. Message Format .......................................................................................................................................... 23
5.1.3. ISO Latin 1 Character Set ........................................................................................................................... 23
5.1.4. Parameter Ranges ....................................................................................................................................... 24
5.1.5. Assignment of Ranges to new Parameters ................................................................................................. 25
5.1.6. Adding Parameters to Parameter Groups ................................................................................................... 28
5.1.7. Transmission Repetition Rates (Update Rates) .......................................................................................... 28
5.1.8. Naming Convention For Engine Parameters .............................................................................................. 29
5.1.9. Application Notes ....................................................................................................................................... 29
5.2. Parameter Definitions ................................................................................................................................. 29
spn16 - Fuel Filter (Suction Side) Differential Pressure (see also SPN 1382) ........................................................ 30
spn21 - Engine ECU Temperature (use SPN 1136) ................................................................................................ 30
spn22 - Extended Crankcase Blow-by Pressure ...................................................................................................... 30
spn39 - Tire Pressure Check Interval ...................................................................................................................... 31
spn46 - Pneumatic Supply Pressure ........................................................................................................................ 31
spn51 - Throttle Position ......................................................................................................................................... 31
spn52 - Engine Intercooler Temperature ................................................................................................................. 31
spn53 - Transmission Synchronizer Clutch Value .................................................................................................. 31
spn54 - Transmission Synchronizer Brake Value ................................................................................................... 31
spn59 - Shift Finger Gear Position .......................................................................................................................... 32
spn60 - Shift Finger Rail Position ........................................................................................................................... 32
spn69 - Two Speed Axle Switch ............................................................................................................................. 32
spn70 - Parking Brake Switch ................................................................................................................................. 32
spn72 - Blower Bypass Valve Position ................................................................................................................... 32
spn73 - Auxiliary Pump Pressure ............................................................................................................................ 33
spn74 - Maximum Vehicle Speed Limit ................................................................................................................. 33
spn75 - Steering Axle Temperature ......................................................................................................................... 33
spn79 - Road Surface Temperature ......................................................................................................................... 33
spn80 - Washer Fluid Level .................................................................................................................................... 33
spn81 - Particulate Trap Inlet Pressure .................................................................................................................... 34
spn82 - Air Start Pressure ........................................................................................................................................ 34
spn84 - Wheel-Based Vehicle Speed ...................................................................................................................... 34
spn86 - Cruise Control Set Speed ............................................................................................................................ 34
spn87 - Cruise Control High Set Limit Speed ......................................................................................................... 34
spn88 - Cruise Control Low Set Limit Speed ......................................................................................................... 34
spn90 - Power Takeoff Oil Temperature ................................................................................................................. 35
spn91 - Accelerator Pedal Position 1 ....................................................................................................................... 35
spn92 - Percent Load At Current Speed .................................................................................................................. 35
spn94 - Fuel Delivery Pressure ................................................................................................................................ 35
spn95 - Fuel Filter Differential Pressure ................................................................................................................. 36
spn96 - Fuel Level ................................................................................................................................................... 36
spn97 - Water In Fuel Indicator ............................................................................................................................... 36
spn98 - Engine Oil Level ......................................................................................................................................... 36
spn99 - Engine Oil Filter Differential Pressure ....................................................................................................... 36
spn100 - Engine Oil Pressure .................................................................................................................................... 37
spn101 - Crankcase Pressure ..................................................................................................................................... 37
spn102 - Boost Pressure ............................................................................................................................................ 37
Vehicle Application Layer - J1939-71 (through December 2001) - p. 1
spn103 - Turbocharger 1 Speed ................................................................................................................................. 37
spn104 - Turbocharger Lube Oil Pressure 1 .............................................................................................................. 37
spn105 - Intake Manifold 1 Temperature .................................................................................................................. 38
spn106 - Air Inlet Pressure ........................................................................................................................................ 38
spn107 - Air Filter 1 Differential Pressure ................................................................................................................ 38
spn108 - Barometric Pressure .................................................................................................................................... 38
spn109 - Coolant Pressure ......................................................................................................................................... 38
spn110 - Engine Coolant Temperature ...................................................................................................................... 39
spn111 - Coolant Level ............................................................................................................................................. 39
spn112 - Coolant Filter Differential Pressure ............................................................................................................ 39
spn114 - Net Battery Current .................................................................................................................................... 39
spn115 - Alternator Current ....................................................................................................................................... 39
spn116 - Brake Application Pressure ........................................................................................................................ 39
spn117 - Brake Primary Pressure .............................................................................................................................. 40
spn118 - Brake Secondary Pressure .......................................................................................................................... 40
spn119 - Hydraulic Retarder Pressure ....................................................................................................................... 40
spn120 - Hydraulic Retarder Oil Temperature .......................................................................................................... 40
spn123 - Clutch Pressure ........................................................................................................................................... 40
spn124 - Transmission Oil Level .............................................................................................................................. 41
spn126 - Transmission Filter Differential Pressure ................................................................................................... 41
spn127 - Transmission Oil Pressure .......................................................................................................................... 41
spn129 - Injector Metering Rail 2 Pressure (duplicate, use 1349) ............................................................................ 41
spn132 - Inlet Air Mass Flow Rate ............................................................................................................................ 41
spn136 - Auxiliary Vacuum Pressure Reading ......................................................................................................... 42
spn137 - Auxiliary Gage Pressure Reading 1 ............................................................................................................ 42
spn138 - Auxiliary Absolute Pressure Reading ......................................................................................................... 42
spn141 - Trailer, Tag Or Push Channel Tire Pressure Target ................................................................................... 42
spn142 - Drive Channel Tire Pressure Target ........................................................................................................... 42
spn143 - Steer Channel Tire Pressure Target ............................................................................................................ 43
spn144 - Trailer, Tag Or Push Channel Tire Pressure ............................................................................................... 43
spn145 - Drive Channel Tire Pressure ....................................................................................................................... 43
spn146 - Steel Channel Tire Pressure ........................................................................................................................ 43
spn156 - Injector Timing Rail 1 Pressure .................................................................................................................. 43
spn157 - Injector Metering Rail 1 Pressure ............................................................................................................... 44
spn158 - Battery Potential (Voltage), Switched ........................................................................................................ 44
spn159 - Gas Supply Pressure ................................................................................................................................... 44
spn160 - Main Shaft Speed ........................................................................................................................................ 44
spn161 - Input Shaft Speed ........................................................................................................................................ 44
spn162 - Transmission Requested Range .................................................................................................................. 45
spn163 - Transmission Current Range ...................................................................................................................... 45
spn164 - Injection Control Pressure .......................................................................................................................... 45
spn165 - Compass Bearing ........................................................................................................................................ 45
spn166 - Rated Engine Power ................................................................................................................................... 46
spn167 - Alternator Potential (Voltage) .................................................................................................................... 46
spn168 - Electrical Potential (Voltage) ..................................................................................................................... 46
spn169 - Cargo Ambient Temperature ...................................................................................................................... 46
spn170 - Cab Interior Temperature ........................................................................................................................... 46
spn171 - Ambient Air Temperature .......................................................................................................................... 46
spn172 - Air Inlet Temperature ................................................................................................................................. 47
spn173 - Exhaust Gas Temperature ........................................................................................................................... 47
spn174 - Fuel Temperature ........................................................................................................................................ 47
spn175 - Engine Oil Temperature 1 .......................................................................................................................... 47
spn176 - Turbo Oil Temperature ............................................................................................................................... 47
spn177 - Transmission Oil Temperature ................................................................................................................... 48
spn180 - Trailer Weight ............................................................................................................................................. 48
spn181 - Cargo Weight .............................................................................................................................................. 48
spn182 - Trip Fuel ..................................................................................................................................................... 48
spn183 - Fuel Rate ..................................................................................................................................................... 48
spn184 - Instantaneous Fuel Economy ...................................................................................................................... 49
spn185 - Average Fuel Economy .............................................................................................................................. 49
spn186 - Power Takeoff Speed .................................................................................................................................. 49
spn187 - Power Takeoff Set Speed ........................................................................................................................... 49
spn188 - Engine Speed At Idle, Point 1 (Engine Configuration) .............................................................................. 49
spn189 - Rated Engine Speed .................................................................................................................................... 49
Vehicle Application Layer - J1939-71 (through December 2001) - p. 2
spn190 - Engine Speed .............................................................................................................................................. 50
spn191 - Output Shaft Speed ..................................................................................................................................... 50
spn233 - Unit Number (Power Unit) ......................................................................................................................... 50
spn234 - Software Identification ............................................................................................................................... 50
spn235 - Total Idle Hours .......................................................................................................................................... 51
spn236 - Total Idle Fuel Used ................................................................................................................................... 51
spn237 - Vehicle Identification Number ................................................................................................................... 51
spn241 - Tire Pressure ............................................................................................................................................... 51
spn242 - Tire Temperature ........................................................................................................................................ 51
spn244 - Trip Distance .............................................................................................................................................. 51
spn245 - Total Vehicle Distance ............................................................................................................................... 52
spn246 - Total Vehicle Hours .................................................................................................................................... 52
spn247 - Total Engine Hours ..................................................................................................................................... 52
spn248 - Total Power Takeoff Hours ........................................................................................................................ 52
spn249 - Total Engine Revolutions ........................................................................................................................... 52
spn250 - Total Fuel Used .......................................................................................................................................... 53
spn411 - Exhaust Gas Recirculation Differential Pressure ....................................................................................... 53
spn412 - Exhaust Gas Recirculation Temperature .................................................................................................... 53
spn441 - Auxiliary Temperature 1 ............................................................................................................................ 53
spn442 - Auxiliary Temperature 2 ............................................................................................................................ 53
spn444 - Battery 2 Potential (Voltage) ...................................................................................................................... 54
spn512 - Driver's Demand Engine - Percent Torque ................................................................................................. 54
spn513 - Actual Engine - Percent Torque ................................................................................................................. 55
spn514 - Nominal Friction - Percent Torque ............................................................................................................. 56
spn515 - Engine's Desired Operating Speed ............................................................................................................. 56
spn516 - Ground-Based Vehicle Speed ..................................................................................................................... 56
spn517 - Navigation-Based Vehicle Speed ............................................................................................................... 56
spn518 - Requested Torque/Torque Limit ................................................................................................................ 57
spn519 - Engine's Desired Operating Speed Asymmetry Adjustment ...................................................................... 60
spn520 - Actual Retarder - Percent Torque ............................................................................................................... 61
spn521 - Brake Pedal Position ................................................................................................................................... 61
spn522 - Percent Clutch Slip ..................................................................................................................................... 62
spn523 - Current Gear ............................................................................................................................................... 62
spn524 - Selected Gear .............................................................................................................................................. 62
spn525 - Requested Gear ........................................................................................................................................... 62
spn526 - Actual Gear Ratio ....................................................................................................................................... 63
spn527 - Cruise Control States .................................................................................................................................. 63
spn528 - Engine Speed At Point 2 (Engine Configuration) ...................................................................................... 64
spn529 - Engine Speed At Point 3 (Engine Configuration) ...................................................................................... 64
spn530 - Engine Speed At Point 4 (Engine Configuration) ...................................................................................... 65
spn531 - Engine Speed At Point 5 (Engine Configuration) ...................................................................................... 65
spn532 - Engine Speed At High Idle, Point 6 (Engine Configuration) ..................................................................... 65
spn533 - Maximum Momentary Engine Override Speed, Point 7 (Engine Configuration) ...................................... 65
spn534 - Maximum Momentary Override Time Limit (Engine Configuration) ....................................................... 66
spn535 - Requested Speed Control Range Lower Limit (Engine Configuration) ..................................................... 66
spn536 - Requested Speed Control Range Upper Limit (Engine Configuration) ..................................................... 66
spn537 - Requested Torque Control Range Lower Limit (Engine Configuration) ................................................... 66
spn538 - Requested Torque Control Range Upper Limit (Engine Configuration) ................................................... 66
spn539 - Percent Torque At Idle, Point 1 (Engine Configuration) ............................................................................ 67
spn540 - Percent Torque At Point 2 (Engine Configuration) .................................................................................... 67
spn541 - Percent Torque At Point 3 (Engine Configuration) .................................................................................... 67
spn542 - Percent Torque At Point 4 (Engine Configuration) .................................................................................... 68
spn543 - Percent Torque At Point 5 (Engine Configuration) .................................................................................... 68
spn544 - Reference Engine Torque (Engine Configuration) ..................................................................................... 68
spn545 - Gain (Kp) Of The Endspeed Governor (Engine Configuration) ................................................................ 68
spn546 - Retarder Speed At Idle, Point 1 (Retarder Configuration) ......................................................................... 69
spn547 - Retarder Speed At Peak Torque, Point 5 (Retarder Configuration) ........................................................... 69
spn548 - Maximum Retarder Speed, Point 2 (Retarder Configuration) .................................................................... 69
spn549 - Retarder Speed At Point 3 (Retarder Configuration) ................................................................................. 69
spn550 - Retarder Speed At Point 4 (Retarder Configuration) ................................................................................. 69
spn551 - Percent Torque At Idle, Point 1 (Retarder Configuration) ......................................................................... 69
spn552 - Percent Torque At Maximum Speed, Point 2 (Retarder Configuration) .................................................... 70
spn553 - Percent Torque At Point 3 (Retarder Configuration) ................................................................................. 70
spn554 - Percent Torque At Point 4 (Retarder Configuration) ................................................................................. 70
Vehicle Application Layer - J1939-71 (through December 2001) - p. 3
spn555 - Percent Torque At Peak Torque, Point 5 (Retarder Configuration) ........................................................... 70
spn556 - Reference Retarder Torque (Retarder Configuration) ................................................................................ 71
spn557 - Retarder Control Method (Retarder Configuration) ................................................................................... 71
spn558 - Accelerator Pedal 1 Low Idle Switch ......................................................................................................... 71
spn559 - Accelerator Pedal Kickdown Switch .......................................................................................................... 71
spn560 - Driveline Engaged ...................................................................................................................................... 72
spn561 - ASR Engine Control Active ....................................................................................................................... 72
spn562 - ASR Brake Control Active ......................................................................................................................... 72
spn563 - Anti-Lock Braking (ABS) Active ............................................................................................................... 72
spn564 - Differential Lock State - Central ................................................................................................................ 72
spn565 - Differential Lock State - Central Front ....................................................................................................... 73
spn566 - Differential Lock State - Central Rear ........................................................................................................ 73
spn567 - Differential Lock State - Front Axle 1 ........................................................................................................ 73
spn568 - Differential Lock State - Front Axle 2 ........................................................................................................ 74
spn569 - Differential Lock State - Rear Axle 1 ......................................................................................................... 74
spn570 - Differential Lock State - Rear Axle 2 ......................................................................................................... 74
spn571 - Retarder Enable - Brake Assist Switch ....................................................................................................... 74
spn572 - Retarder Enable - Shift Assist Switch ........................................................................................................ 74
spn573 - Torque Converter Lockup Engaged ........................................................................................................... 75
spn574 - Shift In Process ........................................................................................................................................... 75
spn575 - ABS Off-road Switch ................................................................................................................................. 75
spn576 - ASR Off-road Switch ................................................................................................................................. 75
spn577 - ASR "Hill Holder" Switch .......................................................................................................................... 76
spn578 - Drive Axle Temperature ............................................................................................................................. 76
spn579 - Drive Axle Lift Air Pressure ...................................................................................................................... 76
spn580 - Altitude ....................................................................................................................................................... 76
spn581 - Transmission Gear Ratio ............................................................................................................................ 76
spn582 - Axle Weight ................................................................................................................................................ 76
spn583 - Pitch ............................................................................................................................................................ 77
spn584 - Latitude ....................................................................................................................................................... 77
spn585 - Longitude .................................................................................................................................................... 77
spn586 - Make ........................................................................................................................................................... 77
spn587 - Model .......................................................................................................................................................... 77
spn588 - Serial Number ............................................................................................................................................. 78
spn589 - Alternator Speed ......................................................................................................................................... 78
spn590 - Idle Shutdown Timer State ......................................................................................................................... 78
spn591 - Idle Shutdown Timer Function ................................................................................................................... 79
spn592 - Idle Shutdown Timer Override ................................................................................................................... 79
spn593 - Idle Shutdown has Shutdown Engine ......................................................................................................... 80
spn594 - Idle Shutdown Driver Alert Mode .............................................................................................................. 80
spn595 - Cruise Control Active ................................................................................................................................. 80
spn596 - Cruise Control Enable Switch .................................................................................................................... 80
spn597 - Brake Switch ............................................................................................................................................... 80
spn598 - Clutch Switch ............................................................................................................................................. 81
spn599 - Cruise Control Set Switch .......................................................................................................................... 81
spn600 - Cruise Control Coast (Decelerate) Switch .................................................................................................. 81
spn601 - Cruise Control Resume Switch ................................................................................................................... 81
spn602 - Cruise Control Accelerate Switch .............................................................................................................. 81
spn604 - Transmission Neutral Switch ...................................................................................................................... 82
spn605 - Refrigerant High Pressure Switch .............................................................................................................. 82
spn606 - Momentary Engine Overspeed Enable ....................................................................................................... 82
spn607 - Progressive Shift Disable ............................................................................................................................ 82
spn619 - Parking Brake Actuator .............................................................................................................................. 82
spn681 - Gear Shift Inhibit Request .......................................................................................................................... 83
spn682 - Torque Converter Lockup Disable Request ............................................................................................... 83
spn683 - Disengage Driveline Request ..................................................................................................................... 83
spn684 - Requested Percent Clutch Slip ................................................................................................................... 83
spn685 - Disengage Differential Lock Request - Front Axle 1 ................................................................................. 83
spn686 - Disengage Differential Lock Request - Front Axle 2 ................................................................................. 84
spn687 - Disengage Differential Lock Request - Rear Axle 1 .................................................................................. 84
spn688 - Disengage Differential Lock Request - Rear Axle 2 .................................................................................. 84
spn689 - Disengage Differential Lock Request - Central ......................................................................................... 84
spn690 - Disengage Differential Lock Request - Central Front ................................................................................ 84
spn691 - Disengage Differential Lock Request - Central Rear ................................................................................. 85
Vehicle Application Layer - J1939-71 (through December 2001) - p. 4
