The controller area network (CAN) serial data circuit is a high speed serial data bus used to communicate information between the engine control module (ECM) and the electronic brake control module (EBCM). Traction control is simultaneously controlled by the ECM and the EBCM. The ECM sends engine torque data via serial data communications to the EBCM. The EBCM uses this message to determine traction control operation.
The CAN bus circuit is monitored continuously after the ignition switch is turned to the ON position.
This diagnostic procedure supports the following DTC:
DTC C0241 PCM Indicated Requested Torque Malfunction
The ignition is ON.
• | The EBCM receives an incorrect engine torque message 3 seconds after start-up from the ECM. |
• | The EBCM continuously monitors for invalid data. |
If equipped, the following actions occur:
• | The EBCM will disable the TCS. |
• | The antilock brake system (ABS) telltale is not illuminated. |
• | The ABS is not disabled. |
• | The condition for the DTC is no longer present. |
• | Using a scan tool, clear the DTC function. |
• | The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
Possible causes of this DTC are as follows:
• | Check the ECM DTCs. |
• | Check the EBCM for any communication DTCs, and diagnose any powertrain or communication DTCs first. |
• | The EBCM is not receiving the message from the ECM. |
• | The CAN HI and CAN LO circuits are shorted together. |
• | The CAN HI and CAN LO circuit is shorted to ground. |
• | The CAN HI and CAN LO circuit is shorted to voltage. |
The numbers below refer to the step numbers on the diagnostic table.
This step tests for a short to ground between the CAN HI and CAN LO circuits.
This step tests the CAN HI and CAN LO circuits for a short together.
This step checks to see if the DTC will reset as current.
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: Antilock Brake System Schematics Connector End View Reference: Antilock Brake System Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
Did you find and correct the condition? | Go to Step 6 | Go to Step 3 | |
Using the DMM, test the CAN HI and CAN LO circuits between the ECM and the EBCM for being shorted together or shorted to voltage. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 6 | Go to Step 4 | |
Did DTC C0241 reset? | Go to Step 5 | Go to Step 6 | |
5 | Replace the EBCM. Refer to Control Module References in Computer/Integrating Systems. Did you complete the repair? | Go to Step 6 | -- |
6 |
Does the DTC reset? | Go to Step 2 | System OK |