Autologic Fix: Immobilizer fault diagnostics

Feb. 18, 2016
The vehicle's immobilizer is locked, and a variety of causes could be to blame.

Brand: Peugeot and Citroen

Symptom: The driver reports a non-start situation. 

Cause: Immobilizer locked (various causes)

Fix: 

1. On the AssistPlus, go to BSI Menu > Select parameter measurements > Select immobiliser > Check parameter 'key transponder chip recognised?’

  • If YES, go to step 2.
  • If NO, then consider the internal chip within key or the transponder pick up ring around the ignition barrel as faulty. 

2. On the same parameter screen, is ‘engine control unit locked’ status reading displaying YES or NO?

  • If YES, go to step 5.
  • If NO, go to step 3. 

3. Engine ECU is unlocked, which indicates there is no issue with immobilizer system. Does the engine crack with starter motor?

  • If NO, then check fuses in under bonnet fuse box. (Normal fuse f8 is for the starter solenoid feed and starter motor itself)
  • If YES, go to step 4. 

4. Carry out fault finding using engine ECU parameter measurement screens, checking rpm signal, cam crank signals, fuel pressures etc.

  • Check mechanical items such as cam timing and belt alignment. 
  • If the above checks are good, contact the Assist Technical helpline. Please ensure you have the chassis number, any checks already carried out and the results and fault codes to hand when you call Autologic.

5. Check the wiring and CAN network to the engine ECU and under bonnet fuse box. Use the correct wiring diagrams obtained from the manufacturer’s website to do this.

  • If the above checks are good, contact the Assist Technical helpline. Please ensure you have the chassis number, any checks already carried out and the results and fault codes to hand when you call Autologic.

Information provided by: Autologic Diagnostics

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