C121C - Torque Request Signal Denied

The Technical Definition: This is a chassis code (C-code) indicating that the Anti-lock Braking System (ABS) module rejected a request from the powertrain module to reduce engine torque.

Common Symptoms: The ABS and Traction Control lights will illuminate on the dash, and the Jeep may feel sluggish as the traction control system gets confused.

Typical Fix: On modified Jeeps, this often happens if the steering wheel is not perfectly centered after a suspension lift or heavy off-roading. Re-centering the steering wheel using the drag link adjustment usually clears the fault. If the wheel is straight, a damaged wheel speed sensor is the next suspect.