GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 HUMMER 🢒 2007 🢒 H2 🢒 Body Systems 🢒 Mirrors 🢒 Automatic Day-Night Mirrors Inoperative

Step

Action

Value(s)

Yes

No

Schematic Reference: Inside Rearview Mirror Schematics

Connector End View Reference: Mirror Connector End Views

1

Did you review the operation of the automatic day-night feature of the mirrors and perform the necessary inspections?

--

Go to Step 2

Go to Symptoms - Mirrors

2
  1. Turn ON the ignition, with the engine OFF.
  2. Turn OFF the automatic day-night feature of the inside rearview mirror.
  3. Observe the driver outside rearview mirror.

Does the driver outside rearview mirror remain in a darken state?

--

Go to Step 20

Go to Step 3

3
  1. Turn ON the automatic day-night feature of the inside rearview mirror.
  2. Cover the sensor on the inside rearview mirror back, facing the front window.
  3. Shine a bright light into the sensor on the inside rearview mirror face, facing the rear window.

Does the inside rearview mirror darken?

--

Go to Step 4

Go to Step 5

4

While shining a bright light into the sensor on the mirror face, facing the rear window, observe the driver outside rearview mirror.

Does the driver outside rearview mirror darken?

--

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 9

5
  1. Turn OFF the ignition.
  2. Disconnect the harness connector of the inside rearview mirror.
  3. Measure the resistance between the ground circuit of the inside rearview mirror and a good ground.

Is the resistance less than the specified value?

3 ohms

Go to Step 6

Go to Step 18

6
  1. Turn ON the ignition, with the engine OFF.
  2. Measure the voltage between the ignition voltage circuit and the ground circuit of the inside rearview mirror.

Is the voltage within the specified range?

B+

Go to Step 7

Go to Step 19

7
  1. Place the transmission in PARK.
  2. Measure the voltage between the backup lamp supply voltage circuit and the ground circuit of the inside rearview mirror.

Is the voltage less than the specified value?

0.5 V

Go to Step 8

Go to Backup Lamps Always On

8
  1. Place the transmission in REVERSE.
  2. Measure the voltage between the backup lamp supply voltage circuit and the ground circuit of the inside rearview mirror.

Is the voltage within the specified range?

B+

Go to Step 15

Go to Step 12

9
  1. Turn OFF the ignition.
  2. Disconnect the harness connector C2 of the driver door module (DDM).
  3. Turn ON the ignition, with the engine OFF.
  4. Turn ON the automatic day-night feature of the inside rearview mirror.
  5. Cover the sensor on the mirror back, facing the front window.
  6. Shine a bright light into the sensor on the mirror face, facing the rear window.
  7. Measure the voltage between the automatic day-night signal circuit and the low reference circuit of the driver outside mirror element.

Is the voltage within the specified range?

0.75-1.5 V

Go to Step 11

Go to Step 10

10

Measure the voltage between the automatic day-night signal circuit of the driver outside mirror element and a good ground.

Is the voltage within the specified range?

0.75-1.5 V

Go to Step 14

Go to Step 13

11
  1. Turn OFF the ignition.
  2. Disconnect the harness connector C3 of the DDM.
  3. Connect a 3-amp fused jumper wire between harness connectors C2 and C3 for the automatic day-night signal circuit of driver outside rearview mirror element.
  4. Connect a 3-amp fused jumper wire between harness connectors C2 and C3 for the low reference circuit of driver outside rearview mirror element.
  5. Turn ON the ignition, with the engine OFF.
  6. Turn ON the automatic day-night feature of the inside rearview mirror.
  7. Cover the sensor on the mirror back, facing the front window.
  8. Shine a bright light into the sensor on the mirror face, facing the rear window.
  9. While shining a bright light into the sensor on the mirror face, facing the rear window, observe the driver outside rearview mirror.

Does the driver outside rearview mirror darken?

--

Go to Step 16

Go to Step 17

12

Test the backup lamp supply voltage circuit of the inside rearview mirror for an open or short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 24

Go to Backup Lamps Inoperative

13

Test the automatic day-night signal circuit of the driver outside rearview mirror element for an open or short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find or correct the condition?

--

Go to Step 24

Go to Step 15

14

Test the low reference circuit of the driver outside rearview mirror element for an open or high resistance. Refer to Circuit Testing and Wiring Repairs .

Did you find or correct the condition?

--

Go to Step 24

Go to Step 15

15

Inspect for poor connections at the harness connector of the inside rearview mirror. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 24

Go to Step 21

16

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

Did you find or correct the condition?

--

Go to Step 24

Go to Step 22

17

Inspect for poor connections at the harness connector of the driver outside rearview mirror. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find or correct the condition?

--

Go to Step 24

Go to Step 23

18

Repair an open or high resistance in the ground circuit of the inside rearview mirror. Refer to Wiring Repairs .

Did you complete the repair?

--

Go to Step 24

--

19

Repair an open or short to ground in the ignition voltage circuit of the inside rearview mirror. Refer to Wiring Repairs .

Did you complete the repair?

--

Go to Step 24

--

20

Important:: A short to voltage on the automatic day-night signal circuit of the driver outside rearview mirror element will cause permanent damage to the driver outside rearview mirror and the inside rearview mirror. Both mirrors will have to replaced. The following actions will need to be performed:

  1. Repair a short to voltage on the automatic day-night signal circuit of the driver outside rearview mirror element. Refer to Wiring Repairs .
  2. Replace the inside rearview mirror and the driver outside rearview mirror. Refer to the following:
    3. • Replace the inside rearview mirror. Refer to Control Module References for replacement, setup, and programming.

Did you complete the repair?

--

Go to Step 24

--

21

Replace the inside rearview mirror. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 24

--

22

Replace the DDM. Refer to Control Module References for replacement, setup, and programming.

Is the replacement complete?

--

Go to Step 24

--

23

Replace the driver outside rearview mirror. Refer to Outside Rearview Mirror Replacement .

Did you complete the replacement?

--

Go to Step 24

--

24

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2