For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Fog Lights Schematics Connector End View Reference: Master Electrical Component List
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Are both rear fog lamps inoperative? | Go to Step 3 | Go to Step 9
3 |

1. Install the scan tool.
2. Turn ON the ignition, with the engine OFF.
3. With a scan tool command the Rear Fog Lamps ON from the rear integration module (RIM) output controls special functions list.

Do both rear fog lamps turn ON?

Go to Step 8

Go to Step 4

4 |

1. Turn OFF the ignition.
2. Disconnect the rear fog lamp relay. Refer to Relay Replacement.
3. Turn ON the ignition, with the engine OFF.
4. Probe the rear fog lamp relay control side supply voltage circuit with a test lamp connected to ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 20

5 | Probe the rear fog lamp relay switch side supply voltage circuit with a test lamp connected to ground. Does the test lamp illuminate? | Go to Step 6 | Go to Step 21
6 |

1. Turn OFF the ignition.
2. Connect a test lamp between the rear fog lamp relay control side supply voltage circuit and the rear fog lamp relay control circuit.
3. Turn ON the ignition, with the engine OFF.
4. With a scan tool, command the Rear Fog Lamps ON and OFF from the rear integration module (RIM) output controls special functions list.

Does the test lamp turn ON and OFF with each command?

Go to Step 7

Go to Step 13

7 |

1. Turn OFF the ignition.
2. Connect a 15-amp fused jumper between the rear fog lamp relay switch side supply voltage circuit and the rear fog lamp supply voltage circuit.
3. Turn ON the ignition, with the engine OFF.

Do both rear fog lamps illuminate?

Go to Step 14

Go to Step 12

8 |

1. Turn OFF the ignition.
2. Disconnect the C2 harness connector at the turn signal/multifunction switch.
3. Connect a 3-amp fused jumper between the rear fog lamp switch signal circuit and rear fog lamp switch ground circuit.
4. Turn ON the ignition, with the engine OFF.

Do the rear fog lamps turn ON?

Go to Step 15

Go to Step 10

9 |

1. Turn OFF the ignition.
2. Remove the inoperative rear fog lamp bulb.
3. Connect a test lamp between the inoperative rear fog lamp supply voltage circuit and the inoperative rear fog lamp ground circuit.
4. Turn ON the ignition, with the engine OFF.
5. Turn ON the rear fog lamp switch.

Does the test lamp illuminate?

Go to Step 18

Go to Step 12

10 | Test the rear fog lamp switch ground circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | Go to Step 27 | Go to Step 11
11 | Test the rear fog lamp switch signal circuit for an open, high resistance, or short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 27 | Go to Step 17
12 | Test the rear fog lamp supply voltage circuit for an open, high resistance, or short to ground. Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | Go to Step 27 | Go to Step 19
13 | Test the rear fog lamp relay control circuit for an open, high resistance, or short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 27 | Go to Step 16
14 | Inspect for poor connections at the rear fog lamp relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs. Did you find and correct the condition? | Go to Step 27 | Go to Step 22
15 | Inspect for poor connections at the harness connector of the turn signal/multifunction switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs. Did you find and correct the condition? | Go to Step 27 | Go to Step 23
16 | Inspect for poor connections at the harness connector of the rear integration module (RIM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 27 | Go to Step 24
17 | Inspect for poor connections at the harness connector of the instrument panel module (IPM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs. Did you find and correct the condition? | Go to Step 27 | Go to Step 25
18 | Inspect for poor connections at the inoperative rear fog lamp bulb. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 27 | Go to Step 26
19 | Locate and repair an open or high resistance in the rear fog lamp ground circuit. Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | Go to Step 27 | --
20 | Locate and repair an open or high resistance in the control side supply voltage circuit of the rear fog lamp relay. Refer to Circuit Testing and Wiring Repairs. Did you complete the repair? | Go to Step 27 | --
21 | Locate and repair an open or high resistance in the switch side supply voltage circuit of the rear fog lamp relay. Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | Go to Step 27 | --
22 | Replace the rear fog lamp relay. Refer to Relay Replacement. Did you complete the replacement? | Go to Step 27 | --
23 | Replace the turn signal/multifunction switch. Refer to Turn Signal Multifunction Switch Replacement . Did you complete the replacement? | Go to Step 27 | --
24 | Replace the RIM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 27 | --
25 | Replace the IPM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 27 | --
26 | Replace the inoperative rear fog lamp bulb. Did you complete the replacement? | Go to Step 27 | --
27 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2