P1612

Symptoms

• Engine won't start
• The immobilizer indicator is on
• Check Engine light comes on
• Intermittent engine operation before stopping

Causes

• Open or short circuit in wiring harness
• Immobilizer malfunction
• Problems with the engine control unit
• Software mismatch
• Damaged connectors or corroded contacts

How to Fix

1. Check the integrity of the wiring harness between the ECM and IMMU
2. Inspect and clean connector contacts
3. Check the power and ground of the immobilizer
4. Read immobilizer fault codes
5. Update or reflash ECM/IMMU software
6. Repair only from an authorized dealer

Related codes

Error P1612 by Vehicle Brand