Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the computer that controls the part of the car that switches between two-wheel drive and four-wheel drive is having trouble thinking or working properly.
The Transfer Case Control Module (TCCM) is responsible for controlling the transfer case, which manages the distribution of power between the front and rear wheels. This code indicates a problem with the TCCM's processor.
The C12AD code is triggered when the vehicle's onboard diagnostics system detects a malfunction in the processor of the Transfer Case Control Module. This module is crucial for managing the engagement and disengagement of the four-wheel drive system, ensuring proper power distribution based on driving conditions.
• Four-wheel drive system not engaging
• Warning light on the dashboard
• Unusual noises from the transfer case
• Faulty Transfer Case Control Module
• Software glitch in the TCCM
• Wiring issues or poor electrical connections
Transfer Case: A component in four-wheel drive vehicles that transfers power from the transmission to the front and rear axles.
TCCM: Transfer Case Control Module, the computer that controls the transfer case.
• Check for additional trouble codes
• Inspect the wiring and connectors to the TCCM
• Test the TCCM for proper operation
• Reprogram or update the TCCM software
• Repair or replace damaged wiring or connectors
• Replace the Transfer Case Control Module if faulty
• OBD-II scanner
• Multimeter
• Screwdriver set
$300 - $800
Moderate
• Chevrolet Silverado
• GMC Sierra
• Dodge Ram
• Regular maintenance of the transfer case
• Ensure software updates are applied
• Inspect wiring and connectors periodically
Control Module Issue
• Avoid using four-wheel drive until the issue is resolved
• Consult a professional mechanic for diagnosis and repair
Check with the vehicle manufacturer for warranty coverage on control modules.
This code has been reported in vehicles with electronic four-wheel drive systems, particularly in models with higher mileage.
Moderate – While not immediately dangerous, the issue can lead to further drivetrain problems if not addressed.
Driving with a malfunctioning transfer case can lead to loss of vehicle control, especially in slippery conditions.
• Vehicle in park or neutral
• Engine running
The Transfer Case Control Module is typically located under the vehicle, near the transfer case, or inside the cabin near the driver's side kick panel.
Q: Can I drive with the C12AD code?
A: It's not recommended to drive extensively with this code, especially in conditions requiring four-wheel drive.
Q: How do I reset the C12AD code?
A: The code can be reset with an OBD-II scanner, but it's important to fix the underlying issue first.
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