Diagnostic Test
- CHECK FOR A DTC C121C-TORQUE REQUEST SIGNAL DENIED NOTE: This DTC must be active for the results of this test to be valid and this DTC may set while driving under severe load conditions.
- Turn the ignition on.
- With the scan tool, read and record DTCs.
- With the scan tool, read and record Environmental Data to help identify the conditions in which the DTC was set.
- With the scan tool, erase DTCs.
- Cycle the ignition switch from off to on.
- Start Engine.
- With the scan tool, read and record DTCs and monitor ESP Torque Request status.
Does the scan tool display: C121C-TORQUE REQUEST SIGNAL DENIED?
Yes
- Go to step 2
No
- Perform the ABS-INTERMITTENT CONDITION TEST. See DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure .
- CHECK THE POWERTRAIN DTCs
- With the scan tool, read and record Powertrain DTCs.
Were any Powertrain ESP related DTCs found?
Yes
- Replace the Powertrain Module in accordance with the Service Information.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
No
- Replace the Anti-Lock Brake Module in accordance with the Service Information.
- Perform ABS VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure .
- With the scan tool, read and record Powertrain DTCs.