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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