Four Wheel Drive (4WD) Control Module Fault
The 4WD control module has detected a fault.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The computer controlling the 4WD system is seeing a problem, which might prevent it from engaging or working properly.
What the computer is actually seeing
The 4WD control module gets signals from various sensors regarding the transfer case position and input from the driver. It compares these with the expected operation parameters.
What a healthy reading looks like
Typical input voltage from the 4WD switch should be around 5V in engaged position, and the transfer case position sensor should report back a range of 0.5V to 4.5V depending on the mode.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check the 4WD switch for proper operation—ensure voltage readings match expected values on the connector.
- 22. Inspect the wiring and connectors leading to the 4WD control module for damage or corrosion.
- 33. Test the transfer case motor for proper operation and resistance—should be in spec as per manufacturer guidelines.
- 44. Check for additional codes in the system that may help pinpoint the issue. If only C0371 is present, proceed to the next step.
- 55. If wiring is intact and components test fine, consider testing or replacing the 4WD control module itself. End diagnostics here. Decision: Has the issue been resolved? If yes, clear codes and road test. If no, further diagnostics may be necessary.
Common causes
- Bad 4WD control module
- Faulty wiring or connections to the 4WD module
- Faulty transfer case motor
- Corrosion or damage in connectors
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
It may be drivable but without functional 4WD, avoid off-road or slippery conditions.
Will this code come back after resetting?
If the underlying issue isn't fixed, yes, it will likely return.
Why did this code appear after recent service work?
If wiring or connections were disturbed during service, a fault may have been introduced.
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