U0136Lost Communication With Differential Control Module - Rear
- Generic OBD-II code · Network
- Turns on the check-engine light
- How the car detects it
- U0136 is set when a listener misses the rear differential control module, which operates an electronic limited-slip or twin-clutch rear drive unit. GM's 2019 tables document it in the ECM of the Cadillac XT4 (LSY engine): if message $1CF from the rear drive module stays absent for 10 s while bus A is active and supply exceeds 11 V, the ECM stores U0136 as a Type B fault, so the MIL comes on after two trips. Saab's 2011 9-5 list (XWD all-wheel drive) also names the rear differential module and adds byte 71 for invalid data. Implausible rear-differential data has its own code U0437; the front axle uses U0135. Rear torque distribution switches off with a warning, and the car usually continues with front-wheel drive.
- What you may notice
- AWD or rear differential warning
- Car drives with front-wheel drive only, less traction
- MIL after two trips on GM vehicles
- Likely causes
- LikelyFuse, supply, ground or CAN wiring of the rear drive module faulty
- PossibleCorroded or damaged connector at the rear axle, exposed to spray water
- RareRear differential control module internally faulty
- Repair
- Hard · Usually a job for a workshop.Typical cost: €80 – €2,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.