U043A code meaning
Invalid Data Received From Suspension Control Module B
What U043A means
Suspension control module B is a second chassis controller, often the one that runs adjustable dampers while module A handles levelling. U043A is logged when its frames reach a receiver but fail integrity checks. GM's 2025 tables give the example of the electronic brake module reading the damper control information: a rolling count equal to the previous one or a protection value that does not add up counts as an error, and 8 errors in a sliding window of 16 set the fault. The check runs only between 9 and 16 V, not during engine start and not within 5 s after a power mode change or reset; it is Type C, so no MIL. Ride control may drop to a fixed default and stability functions may be restricted. U0139 is lost contact, U0421 refers to module A.
U043A at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.3 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U043A
- Service suspension or ride control warning
- Ride noticeably firmer or softer than usual
Common causes of U043A
- PossibleDamper module resets or hangs, sending frozen counters
- PossibleLow supply voltage at the suspension module
- Less likelySoftware of suspension and brake modules not matched
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Suspension module b
What each part of U043A means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 3A | The exact fault in that area. |
What to do next
- Note U043A 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 U043A
What does U043A mean?
U043A means "Invalid Data Received From Suspension Control Module B". Suspension control module B is a second chassis controller, often the one that runs adjustable dampers while module A handles levelling. It is a generic code, so it means the same on every make.
Is it safe to drive with U043A?
Drive gently and only to a workshop. With U043A the car can go into limp mode (reduced power) to protect itself.
Will U043A fail an emissions test?
U043A 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 U043A to fix?
Difficulty: workshop only. A typical repair takes 0.3 to 2.5 hours of work. This is a job for a workshop.
Will U043A clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.