What it means
The vehicle network has lost the electric power steering (EPS) control module. Power assist drops out, the steering becomes heavy and the EPS warning lamp lights up.
At a glance
- Usually lights the warning light of the system that lost communication
- The engine or gearbox may go into limp mode
How it works
Despite the code title, the supplied meaning describes loss of communication with the electric power steering control module. That module exchanges steering-assist status over the vehicle network; this code sets when expected messages stop arriving, and assist may be lost as a result.
Common causes
Most likely first.
- EPS module unpowered
- CAN wiring to EPS damaged
- Gateway module routing CAN messages incorrectly
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
How to diagnose it
- Scan all modules and record freeze-frame and steering-related codes; check whether the power steering module is offline or whether a broader network fault is present.
- With the vehicle stationary, check for an EPS warning and assess whether steering effort is unusually heavy; do not road-test if steering control is impaired.
- Inspect the steering module's connector and accessible wiring for damage, corrosion, water or a loose fit, taking care around any high-current circuits.
- Check the module's specified power and ground, then test the network wiring and gateway path for opens, shorts or connection faults using manufacturer procedures.
- If power, ground and network wiring are correct, use manufacturer diagnostics to determine whether the steering module or gateway has failed.
Common fixes
- Reconnect or repair a loose, corroded or damaged steering module connector.
- Repair an open or short in the CAN wiring to the steering module.
- Restore the module's specified power or ground by repairing the confirmed feed, fuse or ground connection.
- Correct a gateway routing issue if tests show it is blocking steering-module messages.
- Replace the steering module only after its supplies, network and gateway path are verified.
Can I keep driving?
If steering assist is reduced or steering effort is heavy, stop in a safe place and arrange assistance; steering can require much more effort, especially at low speed. Do not continue driving if you cannot control the vehicle confidently.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.