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Makes 🢒 Chevrolet 🢒 1997 🢒 Corvette 🢒 Body and Accessories 🢒 Stationary Windows 🢒 Rear Defogger Inoperative, Heated Mirrors and Indicator Work

Rear Defogger Inoperative, Heated Mirrors and Indicator Work CJ2

Rear defogger inop, heated mirrors/indicator work (CJ2)

Step

Action

Value(s)

Yes

No

DEFINITION: Only the rear defogger grid is inoperative, the outside heated rearview mirrors are operating when the rear defogger button is depressed. DTCs B0432, B0433, U1255 by the BCM or U1153 by the Instrument Panel Cluster (IPC) has not been set.

1

Where you sent here from the Rear Defogger and Heated Mirror Diagnostic System Check?

Go to Step 2

Go to Rear Defogger and Heated Mirror Diagnostic System Check

2

Are all of the rear window defogger grid lines inoperative?

Go to Step 3

Go to Testing Grid Lines

3

Inspect the RR DEFOG Maxifuse® #48.

Is the fuse open?

Go to Step 4

Go to Step 7

4
  1. Remove the RR DEFOG Mini Relay #44.
  2. Using a DMM, measure for continuity across the relay from terminal 30 to terminal 87.

Is continuity present across these terminals?

Go to Step 13

Go to Step 5

5
  1. Disconnect the Rear Window Defogger Grid connector on the battery side leading toward the RR DEFOG Mini Relay #44.
  2. Using a DMM, measure for continuity between the Rear Window Defogger Grid connector (battery side) terminal A and ground.

Is the resistance infinite?

Refer to BCM DTC B0432

Go to Step 6

6

Repair a short to ground in CKT 293.

Is the repair complete?

Go to Rear Defogger and Heated Mirror Diagnostic System Check

7
  1. Disconnect the RR DEFOG Mini Relay #44 from the instrument panel center.
  2. Disconnect the Rear Window Defogger Grid connector on the battery side leading toward the RR DEFOG Mini Relay #44.
  3. Connect a fused jumper between terminal 30 and terminal 87 of the relay connector.
  4. Using a DMM, measure the voltage between the Rear Window Defogger Grid connector (battery side) terminal A and ground.

Is the voltage within the specified values?

10.0-14.0V

Go to Step 9

Go to Step 8

8

Repair an open or high resistance in CKT 293.

Is the repair complete?

Go to Rear Defogger and Heated Mirror Diagnostic System Check

9
  1. Disconnect the Rear Window Defogger Grid connector on the ground side leading toward G301.
  2. Using a DMM, measure for continuity between the Rear Window Defogger Grid connector (ground side) terminal A and ground.

Is continuity present in CKT 350 between the Rear Window Defogger Grid connector and G301?

Go to Step 11

Go to Step 10

10

Repair an open or high resistance in CKT 350.

Is the repair complete?

Go to Rear Defogger and Heated Mirror Diagnostic System Check

11
  1. Disconnect the Body Control Module (BCM) connector C2.
  2. Reinstall the RR DEFOG Mini Relay #44 into the instrument panel electrical center.
  3. Connect a fused jumper between the BCM connector C2 terminal C3 and ground.
  4. Turn the ignition switch to the RUN position.
  5. Using a DMM, measure the voltage between the Rear Window Defogger Grid connector (battery side) terminal A and ground.

Is the voltage within the specified values?

10.0-14.0V

Go to Step 12

Go to Step 13

12

Replace the BCM.

Is the repair complete?

Go to Rear Defogger and Heated Mirror Diagnostic System Check

13

Replace the RR DEFOG Mini Relay #44.

Is the repair complete?

Go to Rear Defogger and Heated Mirror Diagnostic System Check

Rear Defogger Inoperative, Heated Mirrors and Indicator Work C60

Rear defogger inop, heated mirrors/indicator work (C60)

Step

Action

Value(s)

Yes

No

DEFINITION: Only the rear defogger grid is inoperative, the outside heated rearview mirrors are operating when the rear defogger button is depressed. DTCs B0432, B0433, U1255 by the BCM or U1153 by the Instrument Panel Cluster (IPC) has not been set.

1

Where you sent here from the Rear Defogger and Heated Mirror Diagnostic System Check?

Go to Step 2

Go to Rear Defogger and Heated Mirror Diagnostic System Check

2

Are all of the rear window defogger grid lines inoperative?

Go to Step 3

Refer to Testing Grid Lines

3

Inspect the RR DEFOG Maxifuse® #48.

Is the fuse open?

Go to Step 4

Go to Step 7

4
  1. Remove the RR DEFOG Mini Relay #44.
  2. Using a DMM, measure for continuity across the relay from terminal 30 to terminal 87.

Is continuity present across these terminals?

Go to Step 17

Go to Step 5

5
  1. Disconnect the Rear Window Defogger Grid connector on the battery side leading toward the RR DEFOG Mini Relay #44.
  2. Using a DMM, measure for continuity between the Rear Window Defogger Grid connector (battery side) terminal A and ground.

Is the resistance infinite?

Refer to BCM DTC B0432

Go to Step 6

6

Repair a short to ground in CKT 293.

Is the repair complete?

Go to Rear Defogger and Heated Mirror Diagnostic System Check

7
  1. Disconnect the RR DEFOG Mini Relay #44 from the instrument panel center.
  2. Disconnect the Rear Window Defogger Grid connector on the battery side leading toward the RR DEFOG Mini Relay #44.
  3. Connect a fused jumper between terminal 30 and terminal 87 of the relay connector.
  4. Using a DMM, measure the voltage between the Rear Window Defogger Grid connector (battery side) terminal A and ground.

Is the voltage within the specified values?

10.0-14.0V

Go to Step 9

Go to Step 8

8

Repair an open or high resistance in CKT 293.

Is the repair complete?

Go to Rear Defogger and Heated Mirror Diagnostic System Check

9
  1. Disconnect the Rear Window Defogger Grid connector on the ground side leading toward G301.
  2. Using a DMM, measure for continuity between the Rear Window Defogger Grid connector (ground side) terminal A and ground.

Is continuity present in CKT 350 between the Rear Window Defogger Grid connector and G301?

Go to Step 11

Go to Step 10

10

Repair an open or high resistance in CKT 350.

Is the repair complete?

Go to Rear Defogger and Heated Mirror Diagnostic System Check

11
  1. Disconnect the Body Control Module (BCM) connector C2.
  2. Reinstall the RR DEFOG Mini Relay #44 into the instrument panel electrical center.
  3. Connect a fused jumper between the BCM connector C2 terminal C3 and ground.
  4. Turn the ignition switch to the RUN position.
  5. Using a DMM, measure the voltage between the Rear Window Defogger Grid connector (battery side) terminal A and ground.

Is the voltage within the specified values?

10.0-14.0V

Go to Step 12

Go to Step 17

12
  1. Turn the ignition switch to the RUN position.
  2. Depress the Rear Window Defogger switch.

Does the Defogger ON Indicator light illuminate?

Go to Step 14

Go to Step 13

13

Replace the HVAC Control Head.

Is the repair complete?

Go to Rear Defogger and Heated Mirror Diagnostic System Check

14
  1. Turn the ignition switch to OFF.
  2. Disconnect the HVAC Control Head connector C1.
  3. Using a DMM, measure for continuity between the HVAC Control Head connector C1 terminal D and the BCM connector C2 terminal C10.

Is the CKT 681 continuous between these two connectors?

Go to Step 16

Go to Step 15

15

Repair an open or high resistance in CKT 681.

Is the repair complete?

Go to Rear Defogger and Heated Mirror Diagnostic System Check

16

Replace the BCM.

Is the repair complete?

Go to Rear Defogger and Heated Mirror Diagnostic System Check

17

Replace the RR DEFOG Mini Relay #44.

Is the repair complete?

Go to Rear Defogger and Heated Mirror Diagnostic System Check