U0131

Lost Communication With Power Steering Control Module

Network / Communication Network/Communication CAN Bus Communication 🟡 Moderate — Fix within a week ⚠️ Drive with Care
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What This Actually Means

In plain language — no jargon

Your car's main computer has lost radio contact with the power steering control module, like a walkie-talkie losing signal. Without this connection, the power steering system can't communicate properly with the engine computer.

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Symptoms You May Notice

3 known symptoms for this code
Power steering warning light illuminated on dashboard
Stiff or heavy steering wheel, especially at low speeds
Loss of power-assisted steering functionality
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How Your ECU Detects This

Technical sensor logic and voltage thresholds

The ECM continuously monitors CAN bus communication with the power steering control module through periodic heartbeat messages. When no valid data is received within a specified timeout window, the ECM logs a U0131 fault code indicating a broken communication link.

Voltage & Parameter Thresholds

ParameterNormal RangeFault Condition
CAN Bus Message Timeout Valid PSM message received every 100-200ms No PSM response detected for >500ms
Data Validity Message checksum and sequence counter valid Checksum mismatch or missing consecutive messages
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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex
1
OBD-II Scanner
Scan for all stored and pending codes to identify secondary faults that may have triggered the communication loss.
2
CAN Bus Wiring and Connectors
Inspect the CAN H and CAN L lines at the power steering module for corrosion, loose connections, or damaged insulation and reseat connections firmly.
3
Power Steering Control Module
If wiring checks out, the power steering module itself may need replacement or reprogramming by a dealer.
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When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code U0131 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.

Safety note: OBD-II codes identify the system or circuit where a fault was detected — they do not always identify the exact failed component. A professional mechanic using live sensor data will diagnose the root cause more accurately than replacing parts based on the code alone.
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How to Clear Code U0131

What happens after you fix the fault

Once the fault is repaired, U0131 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.

The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.

✅ Safe to Clear When
  • Fault has been diagnosed and repaired
  • You want to confirm the repair worked
  • Code appeared after a sensor was cleaned
⚠️ Do Not Clear When
  • Preparing for an emissions/PUC test
  • Root cause is still undiagnosed
  • Check engine light is flashing
Emissions test note: Clearing codes resets OBD readiness monitors. Most vehicles need 50–100 km of mixed driving before monitors complete. Do not clear codes immediately before an emissions or PUC inspection.