OBD Code U0131: Lost Communication With Power Steering Control Module

Code U0131 is a network communication error that means your vehicle’s primary control module (typically the Engine Control Module or Body Control Module) cannot communicate with the power steering control module. This is a serious issue because the power steering system relies on electronic control for proper operation. Unlike older mechanical power steering systems, modern vehicles use electronic control modules to manage power steering assist, which is critical for safe vehicle operation.

What Does U0131 Mean?

U0131 is a standardized OBD-II diagnostic trouble code that falls under the “Network Communication” category. The “U” prefix indicates this is a network/communication code, while “0131” specifically refers to lost communication with the power steering control module.

Modern vehicles communicate between different control modules using a Controller Area Network (CAN) bus—a high-speed communication system that allows modules to share data and coordinate vehicle functions. When the primary control module tries to communicate with the power steering module and receives no response (or incomplete data), it sets code U0131.

This code can appear in various control modules depending on your vehicle’s architecture:

• Engine Control Module (ECM)
• Body Control Module (BCM)
• Gateway Module
• Instrument Cluster Module

The power steering control module manages electronic power steering assist, steering angle sensors, torque feedback, and integration with advanced driver assistance systems (ADAS). Loss of communication with this module can affect steering performance and safety systems.

Common Symptoms

• Check Engine Light (CEL) or Warning Light: The most obvious symptom is an illuminated check engine light or power steering warning light on the dashboard
• Stiff Steering: Loss of power steering assist, making the steering wheel harder to turn, especially at low speeds or when parked
• Steering Angle Sensor Issues: The vehicle may not recognize the steering wheel position, affecting stability control and ADAS features
• Loss of ADAS Features: Lane keeping assist, adaptive cruise control, or collision avoidance systems may be disabled
• Reduced Fuel Economy: The engine may run less efficiently without proper steering system feedback
• Intermittent Steering Problems: Power steering may work normally sometimes and fail other times, indicating a loose connection
• Dashboard Warning Messages: Your vehicle may display “Power Steering Fault” or “Service Power Steering” messages
• No Symptoms While Driving: Some vehicles may operate normally despite the code being set, especially if the communication loss is intermittent

Possible Causes

Listed from most to least common:

1. Corroded or Loose CAN Bus Connectors (Most Common) – The CAN bus uses specific connectors that can corrode, loosen, or become damaged. This is the #1 cause of U0131 codes. Check connectors at the power steering module, gateway module, and main control modules.
2. Damaged CAN Bus Wiring – The CAN bus uses two twisted wires (CAN High and CAN Low) that run throughout the vehicle. Rodent damage, impact damage, or corrosion can break these lines, preventing communication.
3. Low Battery Voltage – The CAN bus requires stable voltage to operate. A weak battery, faulty alternator, or parasitic drain can cause communication failures. Voltage below 10.5V will typically cause CAN bus errors.
4. Faulty Power Steering Control Module – The power steering module itself may have failed internally, preventing it from responding to CAN bus messages. This is less common but requires module replacement.
5. Defective Gateway Module or CAN Bus Repeater – Many vehicles use a gateway module to manage CAN bus traffic. A failed gateway can prevent communication between modules.
6. Engine Control Module (ECM) or Body Control Module (BCM) Failure – If the primary module that’s trying to communicate with the power steering module has failed, it won’t be able to establish the connection.
7. Software Issues or Outdated Module Programming – Occasionally, a module may need a software update or reprogram to restore communication compatibility.
8. Ground Connection Problems – Poor ground connections can prevent proper CAN bus operation. Check ground straps and connections at the power steering module and main control modules.
9. Aftermarket Equipment Interference – Recently installed aftermarket electronics, alarms, or modifications may have damaged CAN bus wiring or connectors.

Diagnostic Steps

Follow these steps to diagnose code U0131:

Step 1: Check Battery Voltage

Use a multimeter to check battery voltage with the engine off and running. You should see approximately 12.6V when off and 13.5-14.5V when running. If voltage is low, charge the battery and retest. A weak battery is a common cause of CAN bus communication errors.

Step 2: Scan for Additional Codes

Use a quality OBD-II scanner to pull all stored and pending codes. If you see multiple communication codes (U0100, U0101, U0102, etc.), the problem is likely in the CAN bus wiring or a gateway module rather than the power steering module itself.

Step 3: Visually Inspect Connectors and Wiring

Locate the power steering control module (consult your vehicle’s service manual for location—it’s often near the steering column or in the engine bay). Inspect the connector for:

• Corrosion or green/white oxidation on pins
• Loose or bent pins
• Damaged connector housing
• Water intrusion or moisture

Also visually trace the CAN bus wiring from the power steering module to other modules, looking for damage, pinches, or rodent bites.

Step 4: Check CAN Bus Voltage

With the ignition on (engine off), use a multimeter to check voltage on the CAN High and CAN Low lines at the power steering module connector. CAN High should read approximately 2.5V and CAN Low should also read approximately 2.5V. If readings are significantly different or at 0V/5V, there’s a wiring problem.

Step 5: Test Module Communication with a Scope

If you have access to an oscilloscope, connect it to the CAN bus lines. You should see a differential voltage pattern when the vehicle is running. A flat line indicates no communication.

Step 6: Check Ground Connections

Inspect ground straps and connections at the power steering module and main control modules. Clean any corroded ground connections with a wire brush and ensure tight connections.

Step 7: Clear the Code and Test Drive

If you’ve found and corrected a connection issue, clear the code using your scanner and take a test drive. If the code returns immediately, the problem is likely a faulty module requiring replacement.

Step 8: Module Replacement (If Necessary)

If all connections are clean and voltage is correct, the power steering control module or gateway module may need replacement. This requires professional diagnostic equipment to program the new module.

Repair Cost Estimates

The cost to repair code U0131 varies widely depending on the underlying cause:

• Connector Cleaning/Repair: $50-$150 (DIY) or $100-$300 (shop labor)
• CAN Bus Wiring Repair: $200-$600 depending on extent of damage and location
• Power Steering Control Module Replacement: $400-$1,200 (parts and labor)
• Gateway Module Replacement: $300-$900 (parts and labor)
• ECM or BCM Replacement: $600-$2,000+ (parts and labor, often requires reprogramming)
• Full Diagnostic at a Dealership: $100-$200 (may be waived if you proceed with repairs)

Money-Saving Tip: Start with the cheapest fix first—cleaning corroded connectors. Many U0131 codes are resolved by simply cleaning the power steering module connector with electrical contact cleaner and a soft brush.

Can I Still Drive?

Severity: Medium to High

Whether you can safely drive with code U0131 depends on your vehicle’s design and whether you have power steering assist:

Safe to Drive (Short Distances):

• If power steering is still functioning normally and the check engine light is the only symptom, you can typically drive to a repair shop
• Modern vehicles often have failsafe modes that allow manual steering even if the module is offline

Not Safe to Drive:

• If you notice stiff steering or loss of power steering assist, do not drive the vehicle. Manual steering at highway speeds or in traffic is dangerous
• If ADAS features are disabled (lane keeping assist, adaptive cruise control), your vehicle’s safety systems are compromised
• If the code is intermittent and steering cuts out unexpectedly, the vehicle is unsafe to drive

Recommendation: Have the code diagnosed within 24-48 hours. While you may be able to drive short distances, a communication loss with the power steering module could worsen and leave you without steering assist. Do not ignore this code.

Frequently Asked Questions