C121C on 2021-2024 Jeep Grand Wagoneer — Manufacturer-Specific Chassis Control Code
1 vehicles · 1 makes · $650-$2,200 repair
Most Reported On
C121C is an OBD-II diagnostic trouble code meaning “Manufacturer-Specific Chassis Control Code.” C121C is an obscure, manufacturer-specific chassis trouble code without an established generic SAE definition. It generally indicates that a chassis control module (ABS, traction/stability, steering, or suspension) detected a fault in a monitored circuit or component, with the hexadecimal suffix indicating a manufacturer-defined condition. The specific component and severity depend entirely on the vehicle make and model. Confirm the definition with factory service information for your exact vehicle before attempting any diagnosis or repair. This code is most commonly reported on 2021-2024 Jeep Grand Wagoneer, with repair costs ranging from $650 to $2,200.
Common Causes
Typical Repair Cost
Based on 1 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
C121C does not use the standard P/B/C/U prefix. It may be a manufacturer-specific code, so verify that a scanner supports your exact year, model and module before buying.
FAQ
What does C121C mean?
C121C stands for "Manufacturer-Specific Chassis Control Code." C121C is an obscure, manufacturer-specific chassis trouble code without an established generic SAE definition. It generally indicates that a chassis control module (ABS, traction/stability, steering, or suspension) detected a fault in a monitored circuit or component, with the hexadecimal suffix indicating a manufacturer-defined condition. The specific component and severity depend entirely on the vehicle make and model. Confirm the definition with factory service information for your exact vehicle before attempting any diagnosis or repair.
What are the most common causes of C121C?
The most common causes of C121C are: Wiring or connector fault in the monitored circuit, Faulty sensor or actuator in the chassis system, Open or short circuit (to ground or power), Low or unstable supply voltage / poor ground, Internal control module fault, Connector corrosion or moisture intrusion. The specific cause varies by vehicle.
How much does it cost to fix C121C?
Repair costs for C121C range from $650 to $2,200, depending on the vehicle and root cause.
Which vehicles are affected by C121C?
Au7o has documented C121C across 1 vehicle models from 1 manufacturers: Jeep.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.