U0136 on Buick: How to Diagnose & Fix
Lost Communication With Differential Control Module – Rear
1 Buick model · 1 documented issue · $500-$1,100 repair
U0136 on Buick by model: symptoms, diagnosis and fix
On 2013-2018 Encore AWD models the rear differential clutch control module (RDCM) sits low at the rear axle where road splash reaches it over time. Water enters the module and corrodes its circuit board. The most common result is loss of all-wheel-drive engagement with a 'Service AWD' / 'Service StabiliTrak' style message and codes C0800 and/or U0136; in rarer cases the corroded module back-feeds the network and causes a dead battery or loss of electric power-steering assist. Owners on BuickForums also describe the rear clutch randomly engaging with a pop or bang and binding in tight turns before the module fails outright. GM addressed this with Special Coverage bulletin 17436-02 ('Loss of All Wheel Drive Operation Due to Corrosion of Rear Differential Control Module'), which extends coverage on the RDCM and its harness for 2013-2018 AWD Encores.
Common Symptoms
- Service AWD message
- Loss of all-wheel-drive function / front-wheel spin only
- Rear differential randomly engaging with a pop or clunk
- Binding in tight low-speed turns
- Dead battery overnight
- Service Power Steering message or loss of assist
- DTC C0800 and/or U0136 stored
How to Fix
Dealer replaces the corroded RDCM harness and installs an updated RDCM (GM P/N 42463357, tagged with a green dot) and re-secures the harness to its original routing. Check with a dealer for Special Coverage 17436-02 eligibility by VIN before paying - the module and harness were covered well beyond the base warranty under that program. Out of coverage, expect roughly $500-$1,100 for module, harness and labor.
Sources for this issue (3)
U0136 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does U0136 mean on a Buick?
U0136 stands for "Lost Communication With Differential Control Module – Rear." Sets when a module loses data-bus communication with the rear Differential Control Module (electronic/active or e-locker rear differential) and no longer receives its expected messages. On Buick it is documented across 1 model: Encore.
What are the most common causes of U0136?
The most common causes of U0136 are: Open or shorted bus wiring to the rear differential module, Corroded or loose connector, Blown fuse / lost power or ground, Low battery voltage, Failed rear differential control module. The specific cause varies by vehicle.
How much does it cost to fix U0136 on a Buick?
Published repair estimates on Buick range from $500 to $1,100 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for U0136 on a different make?
View U0136 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.