U0249 code meaning
Lost Communication With Entertainment Control Module - Rear B
What U0249 means
Rear B is the second rear entertainment unit; GM applies the code to a concrete part. Its 2011 Saab 9-5 code list names U0249 as lost communication with the rear radio audio control module, the rear seat audio controls with their own headphone outputs. On 2013–2014 Buick Enclave, Chevrolet Traverse and GMC Acadia the radio and the HVAC module stored U0249 within a long list of U codes when the side object sensor harness at the right rear rubbed through on the muffler and disturbed the LAN wiring; the cure was repairing and rerouting that harness (PI1202). The case shows that one chafed lead can silence modules far from the damage. Without unit B, rear audio controls, headphone sound or the second rear screen stop. Rear unit A is U0196, invalid data from B U054A.
U0249 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0249
- Rear audio controls or headphone outputs dead
- Second rear screen without picture
- Many U codes across modules, radio may switch off while driving
Common causes of U0249
- Most likelyChafed or burnt network wiring elsewhere in the vehicle (GM: harness on muffler)
- PossibleRear unit without power or ground
- PossibleLoose or corroded connector at the rear unit
- Less likelyRear unit internally faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Entertainment module rear bCAN bus
What each part of U0249 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 49 | The exact fault in that area. |
What to do next
- Note U0249 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 U0249
What does U0249 mean?
U0249 means "Lost Communication With Entertainment Control Module - Rear B". Rear B is the second rear entertainment unit; GM applies the code to a concrete part. It is a generic code, so it means the same on every make.
Is it safe to drive with U0249?
U0249 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U0249 fail an emissions test?
U0249 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 U0249 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will U0249 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.