C121C
C121C - Torque Request Signal Denied
For a complete wiring diagram, refer to.
• When Monitored: With the engine running.
• Set Condition: When the powertrain control module indicates, for an extended period of time, that engine management relevant for automatic yaw control/traction control system control can not be accomplished.
Test Step 1 - Test for DTC C121C - Torque Request Signal Denied
• 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 Test Step 2 => [ Test Step 2 - Test the Powertrain DTCs ]
No
• Perform the ABS Intermittent Condition Test. Refer to => Non-DTC Based Diagnostics. ABS Intermittent Condition Test
Test Step 2 - Test the Powertrain DTCs
• With the scan tool, read and record Powertrain DTCs.
Were any Powertrain related DTCs found?
Yes
• Repair the Powertrain Diagnostics. Refer to => Engine DTC-Based Diagnostics.
No
• Go to Test Step 3 => [ Test Step 3 - ESP Torque Request Signal ]
Test Step 3 - ESP Torque Request Signal
• Engine started.
• With the scan tool, read the Allow ESP Torque Request status bit.
Was the allow ESP torque request showing NOT set?
Yes
• Replace the Powertrain Module.
• Perform Powertrain Verification Test. Refer to => Engine DTC-Based Diagnostics. PCM Verification Test
No
• Replace the anti lock brake module.
• Perform ABS Verification Test. Refer to => Non-DTC
Based Diagnostics. ABS Verification Test