SCHEMATIC REFERENCE: Defogger Schematics

Did you perform the Defogger Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Defogger

1. Turn ON the ignition, with the engine OFF.
2. Depress the rear defogger button.
3. Connect a test lamp between the left side of the rear defogger grid and the right side of the rear defogger grid.

Does the test lamp illuminate?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

Inspect the RR DEFOG fuse for an open.

Is the fuse open?

Go to Step 16

Go to Step 4

1. With a scan tool, observe the rear defogger relay parameter in Rear Integration Module (RIM) output controls data list.
2. Depress the rear defogger button.

Does the rear defogger relay parameter display ON?

Go to Step 5

Go to Step 22

5

1. Select from the special functions, the rear defogger relay from the RIM output controls.
2. With a scan tool, command the rear defogger relay ON and OFF.

Do you hear a click when you command the rear defogger relay ON and OFF?

Go to Step 8

Go to Step 6

1. Turn OFF the ignition.
2. Remove the rear defogger relay.
3. Turn ON the ignition, with the engine OFF.
4. Connect a test lamp between the Ignition 1 voltage circuit of the rear defogger relay coil and a good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 17

1. Turn OFF the ignition.
2. Connect a test lamp between the control circuit of the rear defogger relay and the Ignition 1 voltage circuit of the rear defogger relay coil.
3. Turn ON the ignition, with the engine OFF.
4. With a scan tool, command the rear defogger relay ON.

Does the test lamp illuminate?

Go to Step 13

Go to Step 12

1. Turn OFF the ignition.
2. Remove the rear defogger relay.
3. Turn ON the ignition, with the engine OFF.
4. Connect a test lamp between the battery positive voltage circuit of the rear defogger relay switch and a good ground.

Does the test lamp illuminate?

Go to Step 9

Go to Step 18

1. Connect a 40 amp fused jumper between the battery positive voltage circuit of the rear defogger relay switch and the supply voltage circuit of the rear defogger.
2. Connect a test lamp between the rear defogger grid and a good ground.

Does the test lamp illuminate?

Go to Step 11

Go to Step 10

Test the supply voltage circuit of the rear defogger for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 15

Test the ground circuit of the rear defogger for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 15

Test the control circuit of the rear defogger relay for an open or short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 14

Inspect for poor connections at the rear defogger relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 19

Inspect for poor connections at the harness connector of the RIM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 20

Inspect for poor connections at the rear defogger. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 21

Repair a short to ground in the supply voltage circuit of the rear defogger. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

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Repair an open or a high resistance in the Ignition 1 voltage circuit of the rear defogger relay coil. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

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Repair an open or high resistance in the battery positive voltage circuit of the rear defogger relay switch. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

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Replace the rear defogger relay.

Did you complete the replacement?

Go to Step 23

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Important: Perform the setup procedure for the Rear Integration Module (RIM).

Replace the RIM. Refer to Rear Integration Body Control Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 23

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Repair or replace the rear window glass. Refer to Bus Bar/Antenna Terminal Repair and Rear Window Replacement .

Did you complete the replacement?

Go to Step 23

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Replace the Instrument Panel Integration Module (IPM). Refer to Instrument Panel Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 23

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2