For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Interior Lights Diagnostic System Check? | -- | Go to Step 2 | Go to Interior Lamps System Check
2 |

1. Install the scan tool.
2. Establish communication with the BCM.
3. Test for any current or history DTCs.

Are there any current or history DTCs present?

--

Go to Diagnostic System Check - Body Control System

Go to Step 3

3 |

1. Use the scan tool in order to turn on the interior lamps.
2. Select INTERIOR LAMPS from the light test menu under special functions on the scan tool.
3. Press the ON button and the OFF button on the scan tool in order to turn the interior lamps on and off.
4. Monitor the scan tool while pressing the ON and OFF buttons. The scan tool can tell you the status of the BCM when either the ON or OFF button has been pressed.

Do the interior lamps turn on when commanded by the BCM?

--

Go to Step 9

Go to Step 4

4 |

1. Locate the multifunction relay K134.
2. Do not disconnect the multifunction relay K134 from its connector.
3. Turn on the ignition.
4. Turn the headlamp switch to the INTERIOR LAMPS ON position.
5. Use a DMM in order to measure the voltage between terminal 2 of the multifunction relay K134 and a known good ground.

Does the voltage measure near the specified value?

B+

Go to Step 6

Go to Step 5

5 | Replace the multifunction relay K134. Did you complete the repair? | -- | Go to Step 12 | --
6 | Use the DMM in order to measure the resistance between terminal 13 of the multifunction relay K134 and a known good ground. Does the resistance measure less than the specified value? | 5 ohms | Go to Step 8 | Go to Step 7
7 |

1. Locate an open or a high resistance in CKT F805.
2. Repair the open or the high resistance in CKT F805.
3. If CKT F805 is OK, replace the multifunction relay K134.

Did you complete the repair?

--

Go to Step 12

--

8 |

1. Locate an open or a high resistance in CKT AP805 and/or CKT XP803.
2. Repair the open or the high resistance in CKT AP805 and/or CKT XP803.

Did you complete the repair?

--

Go to Step 12

--

9 |

1. Turn off the scan tool.
2. Disconnect the BCM connector C2.
3. Turn the headlamp switch to the INTERIOR LAMPS ON position.
4. Use the DMM in order to measure the resistance between terminal D16 of the BCM connector C2 and a known good ground.

Does the resistance measure less than the specified value?

5 ohms

Go to Step 11

Go to Step 10

10 |

1. Locate an open or a high resistance in CKT XY112 and CKT F18.
2. Repair the open or the high resistance in CKT XY112 and CKT F18.
3. If these circuits are OK, replace the headlamp switch. Refer to Headlamp Switch Replacement in Lighting Systems.

Did you complete the repair?

--

Go to Step 12

--

11 | Replace the BCM. Refer to Body Control Module Replacement in Body control System. Did you complete the repair? | -- | Go to Step 12 | --
12 |

1. Connect all connectors and components that were previously disconnected.
2. Verify that the interior lamps operate properly.

Do the interior lamps operate properly?

--

Go to Interior Lamps System Check

Go to Step 1