P1491

Tests 1 - 3:

Tests 4 - 7:

Test 8:

SYMPTOM
P1491-RAD FAN CONTROL RELAY CIRCUIT

POSSIBLE CAUSES
- Intermittent condition
- Fused B+ circuit
- Fused ignition switch circuit
- RAD fan relay control circuit open
- Radiator fan relay control circuit short to ground
- Radiator fan relay
- PCM