U302F code meaning
Ignition Output Accessory
What U302F means
U302F is logged by the module that switches the accessory feed for audio, sockets or windows when that feed is out of step with its own command. Two normal behaviours have to be ruled out first. Keyless systems cut accessory power during cranking: in Tokai Rika's patent US7254466B2 the power supply unit releases the accessory relay when start is requested and re-energizes it only once the engine controller reports that combustion has begun. GM's 2012 pickups, on the other hand, keep accessory voltage on after key-off through a relay inside the BCM for roughly 10 minutes, unless a door is opened. Outside those windows, a live feed in a locked car suggests a welded relay or a driver stuck on, and a dead feed in accessory an open relay, fuse or wire. No manufacturer documents U302F publicly.
U302F at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyEasy, DIY possible
- Typical labor0.3 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U302F
- Radio, sockets or windows dead in accessory mode
- Accessories still on long after locking, battery drained
Common causes of U302F
- PossibleAccessory relay welded or its driver stuck on
- PossibleAccessory relay not pulling in
- PossibleBlown accessory fuse or open feed wire
- Less likelyRetrofitted equipment overloading or backfeeding the accessory feed
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Ignition outputIgnition relayOutput wiring
What each part of U302F means
| U | Network system: communication between the control modules (CAN bus). |
| 3 | Reserved range, usually generic. |
| 2F | The exact fault in that area. |
What to do next
- Note U302F 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 U302F
What does U302F mean?
U302F means "Ignition Output Accessory". U302F is logged by the module that switches the accessory feed for audio, sockets or windows when that feed is out of step with its own command. It is a generic code, so it means the same on every make.
Is it safe to drive with U302F?
U302F does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U302F fail an emissions test?
U302F 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 U302F to fix?
Difficulty: easy. A typical repair takes 0.3 to 2.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will U302F clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.