U0131
NetworkLost Communication with Power Steering Control Module
Most of the time this is a wiring or connection problem rather than a dead steering module, often corrosion or water getting into the power steering harness near the rack or bulkhead. The code itself means another module on the car, usually the engine ECU, has stopped getting messages from the power steering control module over the CAN data network. When the modules can't talk, the system fails safe and you can lose assist. On a lot of cars this turns out to be a poor earth, a chafed wire, or a connector full of road salt rather than an expensive replacement.
ⓘ Information only. This page provides general educational information about fault code U0131. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.
Recommended next steps
Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.
What does U0131 mean?
U0131 is a Network (CAN bus, module communications) fault code. It indicates: Lost Communication with Power Steering Control Module.
This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms commonly associated with this code
Symptoms that drivers often report alongside this code. Not all may apply to every case:
- • Steering goes heavy, especially when parking or crawling in traffic at low speed
- • Power steering warning lamp lit, sometimes with a steering assist message in the cluster
- • Check engine light may come on alongside it
- • A cluster full of lights at once, often ABS and traction control joining in because they share the network
- • Driver aids like lane keep or parking assist stop working
- • Assist that cuts out then comes back on its own, which usually points to a loose or corroded connection rather than a failed module
Possible causes
Causes commonly associated with U0131, listed in approximate order of typical investigation. The actual cause on a specific vehicle can only be confirmed by professional diagnosis.
- 1. Corroded or chafed wiring in the steering module harness, by far the most common culprit on UK cars thanks to road salt and damp getting into connectors near the rack and bulkhead
- 2. Poor earth at the steering rack or module mounting point, a bad ground will drop a module off the network in exactly this way
- 3. Blown fuse feeding the steering control module, simple to check and worth ruling out early
- 4. Pushed-back or damaged pins in the module connector, often from a previous repair or accident damage
- 5. Aftermarket kit such as an OBD tracker, dongle or remote starter loading or disrupting the CAN bus
- 6. A genuine CAN-bus fault, a broken wire, a shorted line, or another module dragging the whole network down
- 7. Internal failure of the power steering control module itself, the least common cause and the one you confirm last, not first
How mechanics typically diagnose
A typical diagnostic sequence used by mechanics, provided here for educational reference only. Diagnostic work should be performed by a qualified mechanic with the appropriate tools and training.
- 1. Scan every module, not just the engine ECU, and read the freeze frame. If several modules report U-codes together you're chasing a network or earth fault, not a single dead module
- 2. Check the fuses feeding the steering module and confirm they actually have power and a clean ground, this is the cheapest thing that fixes it
- 3. Inspect the earth points at the rack and module mounting. Undo them, clean the terminals back to bright metal, and refit tight. A flaky earth mimics a failed module perfectly
- 4. Go over the harness and connector with a torch, looking for green corrosion, chafe marks, water staining, or pins that have backed out, paying attention to the bulkhead and anywhere the loom runs near the rack
- 5. With ignition on and engine off, back-probe the CAN lines at the module connector. You're looking for roughly 2.5V on each line with a small wobble, check manufacturer figures for your car
- 6. If the wiring, earths and bus voltages all check out, then the module is the suspect. Confirm it can't be reached on the scan tool before condemning it
Common questions about U0131
Can I keep driving the car like this? +
I wouldn't. With this code the steering assist can drop out without warning, and the car gets very heavy to turn at parking and junction speeds. It's drivable in a straight line on a motorway, but trying to park or take a tight bend with no assist catches people out. Get it recovered or driven gently to a garage rather than relying on the assist holding up.
Is this going to fail the MOT? +
The fault itself isn't a specific MOT item, but it can cause a fail two ways. If the warning lamp is lit during the test the tester can record it, and from the 2018 rules a lit steering warning lamp is a major defect. On top of that, if the assist is dropping out the tester will feel the steering is impaired during the inspection. Sort the fault and clear the light before booking it in.
What's this likely to cost to put right? +
It hangs entirely on the cause. A blown fuse or a cleaned-up earth is barely two figures in parts, mostly diagnostic time. A wiring or connector repair at an independent typically lands somewhere in the low three figures once labour is in. If it's actually the module, you're into mid to high three figures and sometimes four, because the unit usually needs coding to the car's VIN and the labour isn't quick. A main dealer will charge noticeably more than a good independent for the same job, and the dealer is more likely to fit a new module where an independent will chase the wiring first.
How do I work out which of these it actually is on my car? +
Start with the scan. If only the power steering module is missing and everything else is healthy, look at the module's own power, fuse and earth first. If several modules throw communication codes together, you're almost certainly looking at a network or shared earth problem rather than the steering module. Wiggle-test the harness near the rack and bulkhead while watching live data, intermittent assist that comes and goes is wiring nearly every time. And if you've recently fitted a tracker or plugged a cheap dongle into the OBD port, unplug it and retest before spending a penny.
Information only, not professional advice
The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →