What U0521 means
Other modules receive implausible EPS torque or angle data.
How the engine computer detects it
EPS reduces or disables assist; the EPS warning lamp comes on.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
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
Common causes
- Torque sensor drift Possible
- Gateway module routing CAN messages incorrectly Less likely
- CAN terminating resistor (120 Ω) drifted out of spec Less likely
How to diagnose U0521
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: eps module.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Reading the code
- U
- Network
- 0
- Generic (SAE) code
- 521
- Specific fault
Questions drivers ask
Can I drive with code U0521?
Carefully, and only if the steering feels normal. Power steering assist may be reduced or switched off, which makes the wheel heavy. If steering is heavy or unpredictable, don't drive the car.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.