C0628 code meaning
Variable Effort Steering Module Performance
What C0628 means
C0628 says the unit that runs variable effort steering fails its own function checks. On GM's Magnasteer that unit was a separate module in 1996–97 and became part of the brake control module from 1998. A GM patent describes the logic: a microcomputer reads coil current from speed and lateral acceleration tables, limits the total and its rate of change and drives the coil by PWM; a Steering Solutions patent gives ±3 A full scale. Performance faults cover a driver stage that cannot reach the commanded current, a failed internal self-test or corrupt calibration. GM's Tech 2 can run a function test sweeping the coil current. No maker publishes C0628 in this sense; GM's PIP5094 list (2014 and older) carries the number with an older meaning.
C0628 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyHard
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of C0628
- Steering effort no longer changes with speed
- Heavy steering when parking or light steering at highway speed
- Steering, ABS or stability warning where the brake module hosts the function
Common causes of C0628
- PossibleInternal fault in the controlling module or its coil driver stage
- PossibleLow or unstable supply voltage so the commanded current cannot be reached
- Less likelyCorrupt calibration or software after a module replacement or flash
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Ves module
What each part of C0628 means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 28 | The exact fault in that area. |
What to do next
- Note C0628 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 C0628
What does C0628 mean?
C0628 means "Variable Effort Steering Module Performance". C0628 says the unit that runs variable effort steering fails its own function checks. It is a generic code, so it means the same on every make.
Is it safe to drive with C0628?
Drive gently and only to a workshop. With C0628 the car can go into limp mode (reduced power) to protect itself.
Will C0628 fail an emissions test?
C0628 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 C0628 to fix?
Difficulty: hard. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will C0628 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.