U0477 code meaning
Invalid Data Received From Restraints System Sensor G
What U0477 means
U0477 concerns restraints sensor G, whose messages arrive but are judged invalid; U0176 is lost contact. In Chrysler's lists from NHTSA investigation PE11-019, G names the second satellite on the right flank, an acceleration sensor with internal fault B1B76, and appears only on the six-sensor Compass and Patriot. What invalid data look like in practice is spelled out in Aston Martin's restraint control module manual: for the right C-pillar sensor of the Rapide it separates a dead line, Manchester or parity errors, readings outside the measuring range and plausibility faults, and often suspects a sensor with the wrong part number. Manchester bit coding with a parity bit is the PSI5 frame format. Airbag lamp on, no MIL.
U0477 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyHard
- Typical labor0.8 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0477
- Airbag warning lamp on
- Right rear side impact sensing reduced
Common causes of U0477
- PossibleSensor of an unsuitable part number installed
- PossibleTrapped or chafed sensor line causing corrupted telegrams
- Less likelySensor reporting values outside its measuring range
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Restraints system sensor g
What each part of U0477 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 77 | The exact fault in that area. |
What to do next
- Note U0477 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 U0477
What does U0477 mean?
U0477 means "Invalid Data Received From Restraints System Sensor G". U0477 concerns restraints sensor G, whose messages arrive but are judged invalid; U0176 is lost contact. It is a generic code, so it means the same on every make.
Is it safe to drive with U0477?
U0477 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U0477 fail an emissions test?
U0477 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 U0477 to fix?
Difficulty: hard. A typical repair takes 0.8 to 2.5 hours of work. This is a job for a workshop.
Will U0477 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.