U017C code meaning
Lost Communication With Restraints System Sensor M
What U017C means
U017C is stored once restraint sensor M, the thirteenth remote crash sensor, falls silent. No manufacturer documents U017C publicly. For diagnosis it matters whether the code is current or only stored: according to the PSI5 working group, a brief drop in supply makes a sensor restart and send initialisation data first, so a loose contact can leave a history entry without a lasting fault. Wiggle tests on the connector and harness while watching live status are therefore more useful than replacing parts. Mechanical fit counts too: Audi, for example, inserts its capacitive door pressure sensors into the inner door panel with a seal and turns them to lock, and a poorly seated sensor after trim work can fail. U047D reports invalid data instead of silence. No MIL.
U017C at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyWorkshop only
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U017C
- Airbag warning lamp on or flickering
- Code stored as history after the lamp went out again
- Impact detection in the zone of sensor M unavailable while active
Common causes of U017C
- Most likelyIntermittent contact at sensor M connector (history code)
- PossibleSensor not seated or sealed correctly after trim work
- PossibleSensor wiring chafed or open
- Less likelyCrash sensor M failed
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Restraints sensor mCrash signal wiring
What each part of U017C means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 7C | The exact fault in that area. |
What to do next
- Note U017C 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 U017C
What does U017C mean?
U017C means "Lost Communication With Restraints System Sensor M". U017C is stored once restraint sensor M, the thirteenth remote crash sensor, falls silent. It is a generic code, so it means the same on every make.
Is it safe to drive with U017C?
U017C does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U017C fail an emissions test?
U017C 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 U017C to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will U017C clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.