For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Headlamp Diagnostic System Check performed? | -- | Go to Step 2 | Go to Headlight System Check
2 |

1. Disconnect the inoperative headlamp connector.
2. Turn the headlamp switch to the HEAD position.
3. Complete the following steps if the low beam is inoperative:

• | Turn the headlamp dimmer switch to the LOW position.

• | Use a test lamp in order to backprobe from the inoperative headlamp connector terminal B to ground.

4. Complete the following steps if the high beam is inoperative:

• | Turn the headlamp dimmer switch to the HIGH position.

• | Use a test lamp in order to backprobe from the inoperative headlamp connector terminal C to ground.

Did the test lamp light?

--

Go to Step 3

Go to Step 4

3 |

• | If the low beam is inoperative, use a test lamp in order to frontprobe the inoperative headlamp connector B to headlamp connector A.

• | If the high beam is inoperative, use a test lamp in order to frontprobe the inoperative headlamp connector C to headlamp connector A.

Did the test lamp light?

--

Go to Step 6

Go to Step 7

4 |

1. Complete the following steps for the left headlamp:

• | For the low beam, use a test lamp in order to backprobe between the underhood accessory junction block harness C3 terminal B8 and ground.

• | For the high beam, use a test lamp in order to backprobe between the underhood accessory junction block harness C3 terminal B4 and ground.

2. Complete the following steps for the right headlamp:

• | For the low beam, use a test lamp in order to backprobe between the underhood accessory junction block harness C3 terminal A8 and ground.

• | For the high beam, use a test lamp in order to backprobe between the underhood accessory junction block harness C3 terminal A4 and ground.

Did the test lamp light?

--

Go to Step 5

Go to Step 8

5 |

• | For the low beam, repair an open in CKT 12 between the underhood accessory junction block harness connector and the inoperative headlamp connector terminal B.

• | For the high beam, repair an open in CKT 11 between the underhood accessory junction block harness connector and the inoperative headlamp connector terminal C.

Has the repair been completed?

--

Go to Headlight System Check

--

6 | Replace the headlamp. Refer to Headlamp Replacement . Has the repair been completed? | -- | Go to Headlight System Check | --
7 |

• | For the left headlamp, repair an open in CKT 1350 between the headlamp connector terminal A and G101.

• | For the right headlamp, repair an open in CKT 1250 between the headlamp connector terminal A and G102.

Has the repair been completed?

--

Go to Headlight System Check

--

8 |

• | For the low beam, use a test lamp in order to backprobe between the underhood accessory junction block harness connector C2 terminal F8 to ground.

• | For the high beam, use a test lamp in order to backprobe between the underhood accessory junction block harness connector C2 terminal F4 to ground.

Did the test lamp light?

--

Go to Step 9

Go to Step 10

9 | Replace the underhood accessory junction block. Refer to Relay/Fuse Center Replacement in Wiring Systems. Has the repair been completed? | -- | Go to Headlight System Check | --
10 | Voltage is not present to illuminate the low beams or the high beams. Are the low beam headlamps inoperative or the highbeam headlamps inoperative? | -- | Go to Headlamps Inoperative - Low Beams or Headlamps Inoperative - High Beams | --