Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there's a problem with the sensor that checks the temperature of a part in the car that helps it switch between two-wheel and four-wheel drive. It's like a thermometer that's not working right.
The code C12AC indicates an electrical issue with the temperature sensor circuit in the transfer case control module.
The transfer case control module monitors the temperature of the transfer case to ensure optimal operation. If the module detects an electrical fault in the temperature sensor circuit, it triggers the C12AC code.
• Check engine light is on
• Vehicle may not switch between drive modes properly
• Unusual noises from the transfer case
• Faulty temperature sensor
• Damaged wiring or connectors
• Malfunctioning transfer case control module
Transfer Case: A part of the drivetrain that transfers power from the transmission to the front and rear axles.
Control Module: An electronic device that manages various functions in a vehicle.
• Inspect the wiring and connectors for damage or corrosion.
• Test the temperature sensor for proper operation.
• Check the transfer case control module for faults.
• Replace the faulty temperature sensor.
• Repair or replace damaged wiring or connectors.
• Replace the transfer case control module if necessary.
• OBD-II scanner
• Multimeter
• Socket set
$150 - $500
Moderate
• Jeep Grand Cherokee
• Dodge Ram
• Chevrolet Silverado
• Regularly inspect wiring and connectors.
• Perform routine maintenance on the transfer case.
• Use high-quality replacement parts.
Sensor Issue
• Do not ignore the check engine light.
• Have the vehicle inspected by a professional if unsure.
• Avoid driving in severe conditions until repaired.
Check with the vehicle manufacturer for specific warranty coverage on drivetrain components.
This code has been associated with vehicles that frequently switch between drive modes, leading to wear on the sensor and wiring.
Moderate – It should be addressed soon to prevent further drivetrain issues.
Driving with a malfunctioning transfer case can lead to loss of vehicle control. Ensure repairs are conducted promptly.
• Vehicle is in a safe, stationary position.
• Engine is off and cool to the touch.
The transfer case control module is typically located near the vehicle's drivetrain, under the vehicle.
Q: Can I drive with the C12AC code?
A: It's not recommended as it may affect the vehicle's ability to switch drive modes safely.
Q: How do I reset the C12AC code?
A: After repairs, use an OBD-II scanner to clear the code. If the issue persists, further diagnosis is needed.
Pro · Four-system diagnostics
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