Low beam headlamps inoperative, high beam OK

1. Disconnect headlamp/turn switch connector.
2. Probe circuit 1201 BLU with a test light-to-ground.

•	Lamp lights -- faulty headlamp/turn switch.

•	Lamp does not light -- open circuit 1201.

High beam headlamps inoperative, low beam OK

1. Disconnect headlamp/turn switch connector.
2. Probe circuit 1200 PNK with a test light-to-ground.

•	Lamp lights -- faulty headlamp/turn switch.

•	Lamp does not light -- open circuit 1200.

High and low beam headlamps inoperative

Check circuit 550 at headlamp switch for an open. If OK -- faulty headlamp switch.

High beam indicator does not operate.

Cluster test using Tech 2. If high beam indicator does not work with cluster test -- faulty cluster. Refer to Instrument Cluster Diagnosis in Instrument Panel, Gages and Console.

Right high beam headlamp, daytime running lamp (DRL), Inoperative

Check right high beam headlamp for open element. If OK, check for open 593 or 1200 circuit.

Left high beam headlamp, DRL, inoperative

Check left high beam headlamp for open element. If OK check for open circuit 40 or open circuit 1200.

DRL ON with headlamp switch ON, dimmer switch in low position

1. Using a scan tool, observe high beam input. If voltage is between 6-8 volts, disconnect body control module (BCM) connect or J3 (PNK 24-way).
2. Using a DVOM, check CKT 592, BLK/GRN wire for short to ground.
3. If OK -- faulty BCM.

DRL inoperative, high beam indicator ON with headlamp switch in any position

1. Disconnect BCM connector J1.
2. Probe circuit 1200 with a test light to B+.
3. Turn headlamp switch ON, dimmer switch in the high beam position.

•	Lamp lights -- faulty connection or BCM.

•	Lamp does not light -- open circuit 1200.

DRL lamps do not turn OFF with park brake applied.

1. Disconnect BCM connector J2.
2. Probe circuit 1134 with a test light to B+.
3. Apply park brake.

•	Lamp lights -- faulty connection or BCM.

•	Lamp does not light -- open circuit 1134.