P1388

Tests 1 - 3:

Tests 4 - 8:

SYMPTOM
P1388 - AUTO SHUTDOWN RELAY CONTROL CIRCUIT

WHEN MONITORED
With ignition key ON and battery voltage greater than 10 volts

POSSIBLE CAUSES
- Fused B(+) circuit open
- Auto shutdown relay resistance ≥ 100.0 ohms
- ASD relay control circuit wiring harness intermittent defect
- ASD relay control circuit wiring harness observable defect
- Auto shutdown relay control circuit open
- Auto shutdown relay control circuit shorted to ground
- PCM defective (auto shutdown relay control circuit)