OBD-II trouble code
U0134: Lost Communication With Power Steering Control Module — Rear
The rear power steering (rear-steer) control module has stopped communicating on the vehicle network. Applies to vehicles with four-wheel/rear-wheel steering.
Quick facts
- System
- Network
- Category
- Network Communication
- Severity
- High severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $50 – $1,000
- DIY difficulty
- Shop recommended
What does U0134 mean?
A small number of vehicles — four-wheel-steering trucks and performance/luxury cars with rear-axle steering — carry a dedicated control module for the rear steering actuator. U0134 sets when other modules on the CAN network stop hearing from it. Its front-steering counterpart is U0131; this code is specifically the rear module going silent.
The lost-communication playbook applies: the module most often loses its voice because it lost power or ground (fuse, corroded feed), because its connector or CAN wiring is damaged, or — less often — because the module itself failed. Rear-steer modules and their harnesses live near the rear axle, exposed to spray, salt, and debris, so physical wiring damage is a genuinely common root cause here.
When the module goes offline the system defaults to a safe state: the rear wheels center and lock, and the car steers like a conventional front-steer vehicle, usually with a warning message. You may notice a wider turning circle and less agility, but nothing unsafe. Confirm the vehicle is actually equipped before chasing this code — on non-equipped vehicles a scan tool listing it is usually a misread.
Common causes
- Blown fuse or lost power/ground to the rear steering module
- Corroded or damaged connector near the rear axle (spray/salt exposure)
- Damaged CAN bus wiring to the rear of the vehicle
- Failed rear power steering control module
- Low system voltage setting the code spuriously
Symptoms
- Steering/4WS warning light or message
- Rear wheels locked centered — noticeably wider turning circle
- Reduced low-speed agility or high-speed stability assistance
- Code stored in other modules; vehicle otherwise drives normally
Diagnostic steps
- 1.Confirm the vehicle has rear-wheel steering.
- 2.Check battery and charging voltage first.
- 3.Attempt direct communication with the rear steering module via scan tool.
- 4.Check the module's fuses and power/ground feeds.
- 5.Inspect the rear harness, connectors, and CAN wiring for corrosion or road damage — the high-probability zone.
- 6.Replace and program the module only after its feeds and network wiring prove good.
Repair cost
$50 – $1,000
Wiring and connector repairs at the rear axle are common and moderate in cost. A replacement rear-steer module with programming can run $500-$1,000 depending on the platform. Physical harness damage from road debris is worth ruling out early.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with steering angle sensor service preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
Leave this one to a qualified shop. It typically involves emissions-critical components, refrigerant handling, or other work that requires manufacturer-grade tooling, training, or certification. DIY attempts often produce a more expensive problem than the original code.