C0374 code meaning
4WD Drive Coupling
What C0374 means
No publicly available J2012 list carries C0374; GM uses it in the transfer case control module of its 4WD trucks and SUVs, and PIP5094 names it among GM chassis codes. Dorman's sheets for the S10, Blazer, Astro and Safari, the Trailblazer, Envoy and Isuzu Ascender call it General 4WD Failure: in Auto 4WD the module notices rear wheel slip, commands torque to the front axle and still sees the front and rear propshafts turning at different speeds. After ten attempts that fail to couple the front drive it stores the code. Auto 4WD is then unavailable and Service 4WD stays lit until the next engine start. The fault thus points to the coupling path as a whole, encoder motor, clutch and speed sensors, rather than one circuit.
C0374 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyHard
- Typical labor1 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of C0374
- Service 4WD message until the next engine start
- Auto 4WD does not engage, rear wheels spin on slippery ground
Common causes of C0374
- Most likelyEncoder motor too weak or sticking, so the clutch is not applied
- PossibleFront or rear propshaft speed sensor or its wiring giving false values
- PossibleWorn transfer case clutch pack or wrong fluid
- Less likelyTires of unequal size or pressure faking a speed difference
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Awd couplingTransfer case control moduleEncoder motor
What each part of C0374 means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 74 | The exact fault in that area. |
What to do next
- Note C0374 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about C0374
What does C0374 mean?
C0374 means "4WD Drive Coupling". No publicly available J2012 list carries C0374; GM uses it in the transfer case control module of its 4WD trucks and SUVs, and PIP5094 names it among GM chassis codes. It is a generic code, so it means the same on every make.
Is it safe to drive with C0374?
Drive gently and only to a workshop. With C0374 the car can go into limp mode (reduced power) to protect itself.
Will C0374 fail an emissions test?
C0374 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is C0374 to fix?
Difficulty: hard. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will C0374 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.