Reset the ST165 ECU

When do I want to reset the ECU?

  1. After a performance upgrade e.g. exhaust, air filter
  2. After engine repairs e.g. lambda sensor replacement
  3. To clear stored faults
  4. If the car is playing up, sometimes an ECU reset can cure the fault

Why do I want to reset the ECU?

  1. To restore the ECU to basic settings and to a certain extent "learn" the new engine characteristics
  2. To reset the ECU to factory defaults and again "learn" the new engine characteristics
  3. Certain faults are stored in the memory and some may restrict the operation of the engine e.g. when you hit fuel cut this is stored in memory and whenever you make positive boot pressure then the ECU will cut fuel again - this will keep happening until the ECU is reset

How do I reset the ECU?

There are 2 "levels":

How do I reset the ECU using the easy method?

Locate the main engine bay fuse box - the largest fuse box on the right hand side of the engine bay.

Fuse box cover ECU fuse

Remove the ECU fuse for approx 10 seconds to clear the memory of the ECU. Fuse location shown above.