GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Inspect fuse EF25.

Is fuse EF25 open?

--

Go to Step 2

Go to Step 3

2

  1. Inspect for a short circuit and repair it, if necessary.
  2. Replace fuse EF25.

Is the repair complete?

--

System OK

--

3

  1. Turn the ignition ON.
  2. Measure the voltage at fuse EF25.

Is the voltage at EF25 within the specified value?

11-14 V

Go to Step 5

Go to Step 4

4

Repair the open power supply circuit for fuse EF25.

Is the repair complete?

--

System OK

--

5

Inspect the electric control outside rearview mirrors.

Are both electric control outside rearview mirrors inoperative?

--

Go to Step 6

Go to Step 13

6

  1. Remove the retaining screw for the electric control outside rearview mirror and power window switch assembly.
  2. Lift the switch assembly so that the connectors on the underside are visible.

Is the connector secured to the electric control outside rearview mirror switch?

--

Go to Step 8

Go to Step 7

7

Connect the connector to the electric control outside rearview mirror switch.

Is the repair complete?

--

System OK

--

8

Use an ohmmeter to measure the continuity between terminal 4 (BK) of the electric control outside rearview mirror switch connector and ground.

Does the ohmmeter indicate the specified value?

0 ohms

Go to Step 10

Go to Step 9

9

Repair the open ground circuit for the electric control outside rearview mirror switch.

Is the repair complete?

--

System OK

--

10

  1. Turn the ignition ON.
  2. Measure the voltage at terminal 3 (PNK/BLK) of the electric control outside rearview mirror switch connector.

Is the voltage within to the specified value?

11-14 V

Go to Step 12

Go to Step 11

11

Repair the open power supply circuit for the electric control outside rearview mirror switch.

Is the repair complete?

--

System OK

--

12

Replace the electric control outside rearview mirror switch.

Is the repair complete?

--

System OK

-

13

  1. On the side which has the inoperative mirror, remove the black plastic escutcheon from the trim panel side of the door.
  2. Disconnect the electric control outside rearview mirror electrical connector.
  3. Turn the ignition ON.
  4. At the electric control outside rearview mirror connector, connect a voltmeter between terminal 7 (GY) and terminal 6 (L-GN), if testing the driver side, or PU/WH if testing the passenger side.
  5. Operate the in/out adjustment on the switch, and record the voltage indicated in each switch position.
  6. Connect a voltmeter between terminal 7 (GY) and terminal 4 (WH) if testing the left side, or RD/WH if testing the right side.
  7. Operate the up/down adjustment on the switch, and record the voltage indicated in each switch position.

Does the voltmeter indicate the specified voltage for each test, with the polarity reversing when the switch is changed from in to out or up to down?

11-14 V

Go to Step 14

Go to Step 15

14

Replace the electric control outside rearview mirror.

Is the repair complete?

--

System OK

--

15

  1. Remove the retaining screw for the electric control outside rearview mirror and power window switch assembly.
  2. Lift the switch assembly so that the connectors on the underside are visible.
  3. Leave the electric control outside rearview mirror disconnected, but do not disconnect the mirror switch connector.
  4. Turn the ignition ON.
  5. At the electric control outside rearview mirror switch connector, backprobe to measure the voltage between terminal 7 (GY) and terminal 6 (L-GN) if testing the left side, or PU/WH if testing the right side.
  6. Operate the in/out adjustment on the switch, and record the voltage indicated in each switch position.
  7. Connect a voltmeter between terminal 7 (GY) and terminal 4 (WH) if testing the left side or RD/WH if testing the right side.
  8. Operate the up/down adjustment on the switch, and record the voltage indicated in each switch position.

Does the voltmeter indicate the specified voltage for each test, with the polarity reversing when the switch was changed from in to out or up to down?

11-14 V

Go to Step 16

Go to Step 12

16

Repair the open circuit between the electric control outside rearview mirror switch and the electric control outside rearview mirror connector.

Is the repair complete?

--

System OK

--