COMPUSHIFT Transmission Control Systems follows the SAE J1939 standard for its CAN Bus messaging protocol with a default data rate of 500kb/s. On this page is a table with the commonly used messages when integrating with an Engine Management System connected to the COMPUSHIFT Module via a CAN Bus connection.
Some things to be aware of:
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All of the CAN arbitration ids used are 29 bit, not 11 bit, per J1939.
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In the table below, the last byte of the CAN id is set to “03”, which is the J1939 address for the first transmission control ECU.
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If you change the CAN id address in the COMPUSHIFT Module via the Setup App, you will have to adjust the addresses below accordingly.
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The upper bits of a J1939 arbitration id are used for priority. In all cases, HGM uses the SAE recommended priority and that is shown in the table below.
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In J1939, an all ones bit combination is used to describe the “not available” situation, so if a bit field is all ones, then the system isn’t transmitting that signal.
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For torque management, you will want to use the “shift in process” bits of ETC1. However, not all transmission types transmit this signal.
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Bytes are numbered 1-8, with 1 being the first byte in the CAN frame.
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Bits are numbered 0 to 7, with 0 being the least significant bit in the byte.
|
CAN ID Message Name |
Signal Byte No. | Signal Bit No. | Signal Name (SPN) | Signal Length [Bit] | Value | Name / Phys. Range | Function / Increment Unit |
|---|---|---|---|---|---|---|---|
|
CF00203h ETC1 Electronic Transmission |
1 | 0 | Transmission Driveline Engaged | 2 | 0 | Driveline Disengaged | |
| 1 | Driveline Engaged | ||||||
| 2 | Error | ||||||
| 3 | Not Available | ||||||
| 1 | 2 | Transmission Torque Converter Lockup Engaged | 2 | 0 | Torque Converter Lockup Disengaged | ||
| 1 | Torque Converter Lockup Engaged | ||||||
| 2 | Error | ||||||
| 3 | Not Available | ||||||
| 1 | 4 | Transmission Shift in Process | 2 | 0 | Shift is Not in Process | ||
| 1 | Shift in Process | ||||||
| 2 | Error | ||||||
| 3 | Not Available | ||||||
| 1 | 6 | Transmission Torque Converter Lockup Transition in Process | 2 | 0 | Transition is Not in Process | ||
| 1 | Transition is in Process | ||||||
| 2 | Error | ||||||
| 3 | Not Available | ||||||
| 2 | 0 | Transmission Output Shaft Speed | 16 | 0..8031.88 | 0.125 rpm | ||
| 6 | 0 | Transmission Input Shaft Speed | 16 | 0..8031.88 | 0.125 rpm | ||
|
CF00303h EEC2 Electronic Engine Controls |
2 | 0 | Accelerator Pedal Position 1 | 8 | 0..100 | 0.4 % | |
| 5 | 0 | Accelerator Pedal Position 2 | 8 | 0..100 | 0.4 % | ||
|
CF00403h EEC1 Electronic Engine Controls |
1 | 4 | Actual Engine Percent Torque High Resolution 4154 | 4 | 0..0.875 | 0.125 % | |
| 2 | 0 | Driver s Demand Engine Percent Torque 512 | 8 | -125..125 | % | ||
| 3 | 0 | Actual Engine Percent Torque | 8 | -125..125 | % | ||
| 4 | 0 | Engine Speed | 16 | 0..8031.88 | 0.125 rpm | ||
| 8 | 0 | Engine Demand Percent Torque 2 | 8 | -125..125 | % | ||
|
18F00503h ETC2 Electronic Transmission |
1 | 0 | Transmission Selected Gear | 8 | -125..125 | ||
| 2 | 0 | Transmission Actual Gear Ratio | 16 | 0..64.255 | 0.001 – | ||
| 4 | 0 | Transmission Current Gear | 8 | -125..125 | |||
| 5 | 0 | Transmission Requested Range | 16 | ASCII TEXT | |||
| 7 | 0 | Transmission Current Range | 16 | ASCII TEXT | |||
|
18F00C03h ETC8 Electronic Transmission |
1 | 0 | Transmission Torque Converter Ratio | 16 | 0..64.255 | 0.001 – | |
| 3 | 0 | Transmission Clutch Converter Input Speed 5052 | 16 | 0..8031.88 | 0.125 rpm | ||
|
18F02D03h ACCS Acceleration Sensor |
1 | 0 | Lateral Acceleration Extended Range | 16 | -320..322.55 | 0.01 m/s^2 | |
| 3 | 0 | Longitudinal Acceleration Extended Range | 16 | -320..322.55 | 0.01 m/s^2 | ||
| 5 | 0 | Vertical Acceleration Extended Range | 16 | -320..322.55 | 0.01 m/s^2 | ||
|
18FD9503h TRF2 Transmission Fluids 2 |
1 | 4 | Transmission Overheat Indicator | 2 | 0 | Transmission Overheat Indicator is Off | |
| 1 | Transmission Overheat Indicator is On Continuously | ||||||
| 2 | Transmission Overheat Indicator is Flashing | ||||||
| 3 | Not Available | ||||||
| 2 | 0 | Transmission Torque Converter Oil Outlet Temperature | 16 | -273..1734.97 | 0.03125 deg C | ||
|
18FE4A03h ETC7 Electronic Transmission |
1 | 0 | Transmission Current Range Display Blank State | 2 | 0 | Not Blanked | |
| 1 | Blanked | ||||||
| 2 | Error | ||||||
| 3 | Not Supported | ||||||
| 1 | 2 | Transmission Service Indicator | 2 | 0 | Transmission Service Indicator is Off | ||
| 1 | Transmission Service Indicator is on Continuously | ||||||
| 2 | Transmission Service Indicator is Flashing | ||||||
| 3 | Not Available | ||||||
| 1 | 4 | Transmission Requested Range Display Blank State | 2 | 0 | Inactive; Transmission Requested Range display should NOT be blanked | ||
| 1 | Active; Transmission Requested Range display SHOULD be blanked | ||||||
| 2 | Reserved | ||||||
| 3 | No Action | ||||||
| 1 | 6 | Transmission Requested Range Display Flash State | 2 | 0 | Inactive; Transmission Requested Range display should NOT be flashing | ||
| 1 | Active; Transmission Range display SHOULD be flashing | ||||||
| 2 | Reserved | ||||||
| 3 | No Action | ||||||
| 2 | 2 | Active Shift Console Indicator | 2 | 0 | Primary Shift Console is Active | ||
| 1 | Secondary Shift Console is Active | ||||||
| 2 | Reserved | ||||||
| 3 | Not Available | ||||||
| 2 | 4 | Transmission Engine Crank Enable | 2 | 0 | Cranking Disabled; engine cranking is prohibited by the transmission | ||
| 1 | Cranking Enabled; engine cranking is allowed by the transmission | ||||||
| 2 | Error | ||||||
| 3 | Not Available | ||||||
| 2 | 6 | Transmission Shift Inhibit Indicator | 2 | 0 | Inactive; shift is not inhibited | ||
| 1 | Active (on continuously); shift is inhibited | ||||||
| 2 | Active (flashing) | ||||||
| 3 | No Action | ||||||
| 3 | 0 | Transmission Mode 4 Indicator | 2 | 0 | Transmission Mode 4 Not Active | ||
| 1 | Transmission Mode 4 Active | ||||||
| 2 | Error | ||||||
| 3 | Not Available | ||||||
| 3 | 2 | Transmission Mode 3 Indicator | 2 | 0 | Transmission Mode 3 Not Active | ||
| 1 | Transmission Mode 3 Active | ||||||
| 2 | Error | ||||||
| 3 | Not Available | ||||||
| 3 | 4 | Transmission Mode 2 Indicator | 2 | 0 | Transmission Mode 2 Not Active | ||
| 1 | Transmission Mode 2 Active | ||||||
| 2 | Error | ||||||
| 3 | Not Available | ||||||
| 3 | 6 | Transmission Mode 1 Indicator | 2 | 0 | Transmission Mode 1 Not Active | ||
| 1 | Transmission Mode 1 Active | ||||||
| 2 | Error | ||||||
| 3 | Not Available | ||||||
| 4 | 0 | Transmission Requested Gear Feedback | 8 | -125..125 | |||
| 5 | 0 | Transmission Mode 5 Indicator | 2 | 0 | Disable | ||
| 1 | Enable | ||||||
| 2 | Reserved | ||||||
| 3 | No Action | ||||||
| 5 | 2 | Transmission Mode 6 Indicator | 2 | 0 | Disable | ||
| 1 | Enable | ||||||
| 2 | Reserved | ||||||
| 3 | No Action | ||||||
| 5 | 4 | Transmission Mode 7 Indicator | 2 | 0 | Disable | ||
| 1 | Enable | ||||||
| 2 | Reserved | ||||||
| 3 | No Action | ||||||
| 5 | 6 | Transmission Mode 8 Indicator | 2 | 0 | Disable | ||
| 1 | Enable | ||||||
| 2 | Reserved | ||||||
| 3 | No Action | ||||||
| 6 | 0 | Transmission Reverse Gear Shift Inhibit Status | 2 | 0 | Reverse Gear Shifts are Currently Allowed | ||
| 1 | Reverse Gear Shifts are Currently Inhibited | ||||||
| 2 | Error | ||||||
| 3 | Not Available | ||||||
| 6 | 2 | Transmission Warning Indicator | 2 | 0 | Transmission Warning Indicator is Off | ||
| 1 | Transmission Warning Indicator is On Continuously | ||||||
| 2 | Transmission Warning Indicator is Flashing | ||||||
| 3 | Not Available | ||||||
|
18FE8D03h VEP2 Vehicle Electrical Power |
1 | 0 | Battery Potential Power Input 2 | 16 | 0..3212.75 | 0.05 V | |
| 3 | 0 | ECU Power Output Supply Voltage 1 | 16 | 0..3212.75 | 0.05 V | ||
| 5 | 0 | ECU Power Output Supply Voltage 2 | 16 | 0..3212.75 | 0.05 V | ||
| 7 | 0 | ECU Power Output Supply Voltage 3 | 16 | 0..3212.75 | 0.05 V | ||
|
18FEA403h ET2 Engine Temperature 2 |
3 | 0 | ECU Temperature | 16 | -273..1734.97 | 0.03125 deg C | |
|
18FEAB03h ETC6 Electronic Transmission |
1 | 0 | Recommended Gear | 8 | -125..125 | ||
| 2 | 0 | Highest Possible Gear | 8 | -125..125 | |||
| 3 | 0 | Lowest Possible Gear | 8 | -125..125 | |||
|
18FEF103h CCVS1 Cruise Control Vehicle |
2 | 0 | Wheel Based Vehicle Speed | 16 | 0..250.996 | 0.00390625 km/h | |
|
18FEF803h TRF1 Transmission Fluids 1 |
1 | 0 | Clutch Pressure | 8 | 0..4000 | 16 kPa | |
| 2 | 0 | Transmission Oil Level 1 | 8 | 0..100 | 0.4 % | ||
| 4 | 0 | Transmission Oil Pressure | 8 | 0..4000 | 16 kPa | ||
| 5 | 0 | Transmission Oil Temperature 1 | 16 | -273..1734.97 | 0.03125 deg C | ||
| 7 | 0 | Transmission Oil Level 1 High Low | 8 | -62.5..62.5 | 0.5 L | ||
| 8 | 0 | Transmission Oil Level 1 Countdown Timer | 4 | 0 | Less than 1 Minute | ||
| 1 | One Minute | ||||||
| 2 | Two Minutes | ||||||
| 3 | Three Minutes | ||||||
| 4 | Four Minutes | ||||||
| 5 | Five Minutes | ||||||
| 6 | Six Minutes | ||||||
| 7 | Seven Minutes | ||||||
| 8 | Eight Minutes | ||||||
| 9 | Nine Minutes | ||||||
| 10 | Ten Minutes | ||||||
| 11 | Eleven Minutes | ||||||
| 12 | Twelve Minutes | ||||||
| 13 | Thirteen Minutes | ||||||
| 14 | Error | ||||||
| 15 | Not Available | ||||||
| 8 | 4 | Transmission Oil Level 1 Measurement Status | 4 | 0 | Conditions Valid for Transmission Oil Level Measurement | ||
| 1 | Conditions Not Valid – Setting Timer Still Counting Down | ||||||
| 2 | Conditions Not Valid – Transmission in Gear | ||||||
| 3 | Conditions Not Valid – Transmission Fluid Temperature Too Low | ||||||
| 4 | Conditions Not Valid – Transmission Fluid Temperature Too High | ||||||
| 5 | Conditions Not Valid – Vehicle Moving; Output Shaft Speed Too High | ||||||
| 6 | Conditions Not Valid – Vehicle Not Level | ||||||
| 7 | Conditions Not Valid – Engine Speed Too Low | ||||||
| 8 | Conditions Not Valid – Engine Speed Too High | ||||||
| 9 | Conditions Not Valid – No Request for Reading | ||||||
| 10 | Not Defined | ||||||
| 11 | Not Defined | ||||||
| 12 | Not Defined | ||||||
| 13 | Conditions Not Valid – Other | ||||||
| 14 | Error | ||||||
| 15 | Not Available |
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