P1678
Immobilizer Powertrain Identification Failed
Severity
🔴 HighCan you drive?
Do not drive — repair immediately
Approx. repair cost
$33–167 (est.)
Symptoms
- Engine won't start
- The engine stalls immediately after starting
- The immobilizer indicator is on
- Check Engine light comes on
- No response when turning the ignition key
Causes
- Faulty ignition key (chip)
- Damage to the immobilizer antenna
- Problems with the immobilizer wiring harness
- ECU software failure
- Immobilizer unit malfunction
How to Fix
- Check the condition of the ignition key
- Diagnose the immobilizer antenna
- Check the integrity of the wiring harness
- Reprogram the immobilizer system
- Repair only from an authorized dealer