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 service bulletin 18-NA-007 for 2013-2018 AWD Encores; in Canada, 2013-2017 models are covered by Special Coverage 17436.
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
The dealer installs an updated RDCM (GM P/N 42463357, tagged with a green dot) and re-secures the harness to its original routing. The RDCM harness is replaced only if its connector shows corrosion; GM notes only about 3% of vehicles have a corroded connector. In Canada, ask a dealer to check Special Coverage 17436 eligibility by VIN for 2013-2017 models before paying. Out of coverage, expect roughly $500-$1,100 for module, harness and labor.
Call to confirm they can assess your vehicle and perform the stated work. Search results do not confirm qualification, eligibility or coverage.
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.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.