U0131 – Lost Communication With Power Steering Control Module

System: Network | Standard: ISO/SAE Controlled | Fault type: General

Definition source: SAE J2012/J2012DA (industry standard)

U0131 indicates the vehicle has detected a network communication loss with the power steering control module. In practical terms, one or more other control modules expected to receive messages from the power steering module but did not see them within an allowed time, so the network monitor flagged a lost-communication fault. This is a network-level DTC, so it does not automatically mean the steering system has a mechanical failure or that the power steering module is “bad”; it means communication was not reliable or not present during the monitor conditions. DTC behavior, stored status, and the exact enabling criteria vary by vehicle, so confirm the module location, network topology, and test procedures using the correct service information.

What Does U0131 Mean?

U0131 means Lost Communication With Power Steering Control Module. Per SAE J2012 DTC structure, a “U” code is a network communication fault, and this specific entry is set when the vehicle’s communication system determines that messages from the power steering control module are missing or invalid for long enough to be considered a failure. The code describes a communication condition between modules (or between a module and the network), not a specific sensor signal being high/low or an actuator being stuck. Diagnosis focuses on whether the power steering control module is powered up and connected to the network, and whether the network wiring, connectors, and related modules can exchange data reliably.

Quick Reference

  • Subsystem: Network communications involving the power steering control module (vehicle data bus and related power/ground).
  • Common triggers: Module offline due to power/ground loss, network open/short, poor connector contact, or bus interference causing message timeouts.
  • Likely root-cause buckets: Wiring/connector issues, power/ground supply faults, network bus faults, module internal fault, and (varies by vehicle) configuration/software issues.
  • Severity: Potentially high; steering assist may be reduced or disabled and warning indicators may appear.
  • First checks: Verify steering warnings, check for multiple U-codes, confirm module powers up, inspect connectors/harness near the module, and check battery/charging health.
  • Common mistakes: Replacing steering components before confirming network integrity, ignoring shared power/ground issues, or overlooking other communication DTCs that point to a bus-wide problem.

Theory of Operation

The power steering control module communicates with other modules over the vehicle network, broadcasting status and receiving commands or related data used to coordinate steering assist and system reporting. Other controllers (and sometimes a central gateway, varies by vehicle) continuously expect periodic messages and will flag a fault if those messages stop, are corrupted, or cannot be decoded.

U0131 typically sets when the receiving module(s) detect a message timeout or loss of contact with the power steering control module. This can occur if the power steering module loses power or ground, the network wiring has an open/short or high resistance, connectors have poor terminal contact, or the module is present but cannot participate on the network. Intermittent faults may set during vibration, temperature change, or when harness routing is stressed.

Symptoms

  • Warning lamp steering system warning indicator illuminated.
  • Reduced assist steering feels heavier than normal, especially at low speeds.
  • Message display driver information message related to steering assist or system fault (varies by vehicle).
  • Multiple U-codes additional network communication DTCs stored in other modules.
  • No module data scan tool cannot communicate with the power steering control module or shows it as offline.
  • Intermittent behavior steering warnings or assist changes that come and go with bumps, turns, or temperature changes.
  • Fail-safe mode system enters a default strategy with limited functionality (varies by vehicle).

Common Causes

  • Open circuit, short-to-power, or short-to-ground on the network communication lines between the power steering control module and the rest of the vehicle network
  • Poor connector engagement, backed-out terminals, terminal spread, corrosion, or moisture intrusion at the power steering control module connector or an in-line network connector
  • Power steering control module power feed issue (blown fuse, faulty relay, high resistance in the supply circuit)
  • Power steering control module ground issue (loose ground fastener, corrosion, damaged ground splice, high resistance ground path)
  • High resistance or intermittent wiring fault in the harness (rub-through, pinched section, previous repair, strain at the module)
  • Network backbone fault affecting multiple modules (faulty splice, damaged junction, or connector issue on the shared network segment)
  • Another module or aftermarket device loading the network and preventing reliable communication (varies by vehicle design)
  • Power steering control module internal fault or software/configuration issue (consider only after power/ground and network integrity are verified)

Diagnosis Steps

Tools typically needed include a scan tool that can read network DTCs and module status, access to vehicle-specific wiring diagrams/service information, and a digital multimeter for voltage-drop and continuity checks. A breakout lead set and basic back-probing tools help avoid terminal damage. If available, a lab scope can be useful to evaluate network activity, but many faults can be isolated with scan data and careful electrical testing.

  1. Confirm the complaint and capture data: Verify warning messages/steering assist concerns, then perform a full vehicle scan. Record U0131 and any additional network, power supply, or module-related DTCs. Save freeze frame or event data if the platform provides it.
  2. Check whether the power steering control module is reachable: Attempt to communicate directly with the power steering control module using the scan tool. Note whether it is “no communication,” intermittently available, or fully accessible. This result guides whether you focus first on power/ground or the network segment.
  3. Assess for broader network impact: Look for multiple “lost communication” codes across different modules. If several modules report communication loss, prioritize diagnosing the shared network backbone, common splices, and power distribution rather than condemning a single module.
  4. Verify battery and charging system health: Check for low system voltage indicators or related DTCs. Poor system voltage can cause modules to drop off the network. Correct any battery/charging issues first, then recheck for U0131.
  5. Perform a targeted visual inspection: With ignition off, inspect the module area and harness routing for damage, rub-through, pinched sections, or evidence of water intrusion. Inspect connectors for loose latches, bent pins, corrosion, or pushed-out terminals. Repair obvious physical issues before deeper testing.
  6. Check module power feeds under load: Using wiring diagrams, identify all power feeds to the power steering control module. Test each related fuse for integrity and verify the feed circuit can support load (not just “has voltage”). Use voltage-drop testing across the feed path (battery to module feed) to find high resistance.
  7. Check module grounds with voltage-drop testing: Identify all module grounds and perform voltage-drop tests from the module ground pin(s) to the battery negative while the circuit is loaded (as applicable). Excessive drop indicates resistance at a ground fastener, splice, or conductor that can cause intermittent module resets and communication loss.
  8. Evaluate network circuit integrity at the module connector: With ignition off and per service information precautions, test for opens/shorts between the module connector pins and the network junction/backbone. Check for shorts to power/ground and for continuity where appropriate. Avoid “ohms testing” through connected modules unless service information confirms it is safe.
  9. Wiggle test for intermittents: While monitoring scan tool module status and network DTC counters, gently wiggle the harness, connector, and nearby splices related to the power steering control module. If communication drops in/out, isolate the exact section by moving in smaller increments and inspecting for terminal fretting, broken conductors, or poor strain relief.
  10. Use live-data logging to validate the fix: After repairing any wiring/connector/power/ground issues, clear DTCs and perform a road test or functional test while logging network status and steering-related module availability (where supported). Confirm the module remains online and U0131 does not return under the same conditions that originally triggered it.
  11. Consider module-level causes last: Only after verifying stable power, solid grounds, and correct network integrity should you consider an internal module fault or configuration/software issue. Follow service information for any setup, programming, calibration, or variant coding requirements before replacement.

Professional tip: If U0131 is intermittent, prioritize finding what makes the power steering control module reset or drop offline: a marginal ground, a loose terminal, or harness movement is more common than a failed module. Use scan tool “module alive” status (or communication counters) during a controlled wiggle test, and confirm repairs with voltage-drop tests instead of relying solely on continuity checks.

Need network wiring diagrams and module connector views?

Communication stop and network faults require module connector pinouts, bus wiring routes, and power/ground diagrams. A repair manual helps you trace the exact circuit path before replacing any ECU.

Factory repair manual access for U0131

Check repair manual access

Possible Fixes & Repair Costs

Repair cost for U0131 varies widely because the fix depends on what caused the lost communication (power/ground, network wiring, connector issues, or a module concern). Labor time can also vary based on component access and required network diagnosis.

  • Repair or replace damaged wiring in the communication network between modules (repair verified opens, shorts, or high resistance)
  • Clean, repair, or re-pin poor connector terminals at the power steering control module and any related network junctions (verify pin fit and corrosion)
  • Restore proper power and ground to the power steering control module (repair blown fuse cause, poor ground, or voltage-drop issues)
  • Correct network faults at splices or junction points (repair verified splice corrosion, loose joints, or harness damage)
  • Perform a module reset/relearn procedure if required by service information after communication is restored
  • Update/reprogram the affected control module(s) only if service information confirms a software-related communication issue
  • Replace the power steering control module only after confirming power/ground and network integrity and verifying the module will not communicate

Can I Still Drive With U0131?

Driving with U0131 may be unsafe because losing communication with the power steering control module can lead to reduced or lost power assist, warning indicators, and unpredictable steering feel. If steering assist is reduced, steering warnings are on, or other safety-related warnings appear, do not drive—have the vehicle towed and diagnosed. If steering feels normal and the code is history-only, limit driving and schedule diagnosis promptly, since the condition may be intermittent and return without warning.

What Happens If You Ignore U0131?

Ignoring U0131 can allow an intermittent network or power/ground problem to worsen, potentially causing sudden loss of steering assist, repeated warnings, and additional network communication codes. Continued operation with an underlying wiring fault can lead to more frequent failures, harder diagnosis later, and the risk of a no-assist steering event when you least expect it.

Compare nearby steering lost trouble codes with similar definitions, fault patterns, and diagnostic paths.

  • U0170 – Lost Communication With Steering Angle Sensor Module
  • U0130 – Lost Communication With Steering Effort Control Module
  • U017D – Lost Communication With Control Module “M”
  • U017C – Lost Communication With Control Module “L”
  • U017B – Lost Communication With Control Module “K”
  • U017A – Lost Communication With Control Module “J”

Key Takeaways

  • U0131 indicates lost communication with the power steering control module, not a confirmed mechanical steering failure.
  • Most root causes are network wiring/connector issues or power/ground problems feeding the steering control module.
  • Verify module power, ground, and network integrity before considering module replacement.
  • Intermittent faults are common; capture freeze-frame data and log network/module status during a road test when safe.
  • Reduced or lost steering assist is a safety concern; avoid driving if warnings or abnormal steering feel are present.

Vehicles Commonly Affected by U0131

  • Vehicles equipped with electric power steering where steering assist is controlled by a dedicated control module
  • Vehicles using a high-speed network bus for chassis and steering communications
  • Vehicles with steering control modules mounted low in the vehicle where harness stress or moisture exposure can occur (varies by vehicle)
  • Vehicles with recent battery replacement, low battery events, or charging system concerns that can disrupt module communications
  • Vehicles with prior collision damage or repairs near the front structure, steering gear, or harness routing
  • Vehicles with aftermarket electrical accessories or recent wiring modifications that may affect network circuits
  • High-mileage vehicles where connector terminal tension and ground integrity may degrade over time
  • Vehicles operated in environments that increase corrosion risk at connectors and grounds (varies by vehicle)

FAQ

Does U0131 mean the power steering control module is bad?

No. U0131 only means communication with the power steering control module was lost. The cause can be the module, but it is often a power/ground supply problem, a wiring/connector issue, or a network fault that prevents messages from reaching or leaving the module.

Can a weak battery cause U0131?

Yes, it can. Low system voltage during cranking or charging system instability can cause modules to drop off the network or reset, which may set a lost communication code. Confirm battery and charging system health and check for related low-voltage or reset codes.

Why does U0131 come and go?

Intermittent U0131 is commonly caused by loose terminals, harness movement, marginal grounds, or a developing break in a wire. Heat, vibration, and moisture can temporarily change resistance or connection quality, so logging data and performing wiggle testing during diagnosis is important.

Will clearing the code fix U0131?

Clearing may turn off warnings temporarily, but it does not correct the underlying reason communication was lost. If the root cause remains, the code will typically return when the fault condition occurs again, sometimes during the next key cycle or while driving.

What should be checked first for U0131?

Start by verifying whether the power steering control module is communicating on a scan tool, then check its power and grounds (including voltage-drop testing under load), inspect network wiring/connectors for damage or corrosion, and look for other communication or low-voltage codes that help narrow the failure path.

Confirm the repair by restoring stable communication with the power steering control module, clearing codes, and completing a monitored road test while watching module status and network-related data to ensure U0131 does not return.