Component replacement
Before replacing the electric power steering ECU, the battery must be disconnected.
Procedure to follow after disconnecting the battery
After each battery disconnection, the steering wheel angle is invalid (remains at 0) and the ET020 status is "State 3". Following a road test, this results in a fault in Dynamic Driving Control.
Therefore, after each battery disconnection, turn the steering wheel a quarter turn to the left, then a quarter turn to the right, and return the steering wheel to the straight-ahead centre position, with the engine running.
If the fault persists, stop and restart the engine without touching the ESP button, and repeat the previous procedure.
ECU replacement
Each time the Electric Power Steering ECU is replaced, configure the ECU for the vehicle concerned (see CF088 or SC001) and perform the steering wheel angle learning (CF085).
Any ECU replacement must be carried out with ignition switched off.
Test yourself
A quick Renault Megane quiz: every answer comes with an explanation and a link to the manual page.