GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2001 🢒 Catera 🢒 Body and Accessories 🢒 Stationary Windows 🢒 DTC 019

Circuit Description

The memory seat module (MSM) supplies 5 volts and low reference to the inside rearview mirror. The MSM monitors the voltage of the horizontal and vertical signal circuits of the inside rearview mirror to determine the position of the mirror. The normal voltage range is between 0.16 volts and 4.6 volts.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

One of the following conditions can cause this DTC to set:

    • No mirror movement detected by the MSM during a memory recall command.
    • Voltage is less than 0.16 volts or greater than 4.6 volts on the horizontal or vertical signal circuit of the inside rearview mirror.

Action Taken When the DTC Sets

The automatic adjustment of the inside rearview mirror is disable.

Conditions for Clearing the DTC

The DTC will clear from current status when one of the following conditions is met:

    • Mirror movement is regained during a command from the MSM.
    • Voltage is between 0.16 volts and 4.6 volts on the horizontal or vertical signal circuit of the inside rearview mirror.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. Tests for the proper operation of the circuit in the high voltage range.

    2.

  2. Tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.

    3.

  3. Tests for a short to ground in the 5 volt reference circuit.

    4.

  4. Tests for the proper operation of the circuit in the high voltage range.

    5.

  5. Tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.

    6.

  6. Tests for a short to ground in the 5 volt reference circuit.

Step

Action

Value(s)

Yes

No

Schematic Reference: Inside Rearview Mirror Schematics

1

Did you perform the Stationary Windows Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Stationary Windows

2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Select the Inside Mirror Control from the Memory Seat Module (MSM) output controls.
  4. With a scan tool, command the inside rearview mirror Up and Down.

Does the mirror move Up and Down?

--

Go to Step 3

Go to Step 4

3

With a scan tool, command the mirror Left and Right.

Does the mirror move Left and Right?

--

Go to Step 8

Go to Step 6

4
  1. Turn OFF the ignition.
  2. Disconnect the harness connector of the inside rearview mirror.
  3. Connect a test lamp between the mirror up circuit of the inside rearview mirror and a good ground.
  4. Turn ON the ignition, with the engine OFF.
  5. With a scan tool, command the inside rearview mirror to the UP position.

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 16

5
  1. Connect a test lamp between the mirror up circuit of the inside rearview mirror and the motor control circuit of the inside rearview mirror.
  2. With a scan tool, command the inside rearview mirror to the DOWN position.

Does the test lamp illuminate?

--

Go to Step 24

Go to Step 18

6
  1. Turn OFF the ignition.
  2. Disconnect the harness connector of the inside rearview mirror.
  3. Connect a test lamp between the mirror right circuit of the inside rearview mirror and a good ground.
  4. Turn ON the ignition, with the engine OFF.
  5. With a scan tool, command the inside rearview mirror to the RIGHT position.

Does the test lamp illuminate?

--

Go to Step 7

Go to Step 17

7
  1. Connect a test lamp between the mirror right circuit of the inside rearview mirror and the motor control circuit of the inside rearview mirror.
  2. With a scan tool, command the inside rearview mirror to the LEFT position.

Does the test lamp illuminate?

--

Go to Step 24

Go to Step 18

8

With a scan tool, observe the interior mirror horizontal position data parameter in the MSM data list.

Does the scan tool indicate that the interior mirror horizontal position data parameter is within the specified range?

0.16-4.6 V

Go to Step 9

Go to Step 10

9

With a scan tool, observe the interior mirror vertical position data parameter in the MSM data list.

Does the scan tool indicate that the interior mirror vertical position data parameter is within the specified range?

0.16-4.6 V

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

Go to Step 13

10

  1. Turn OFF the ignition.
  2. Disconnect the harness connector of the inside rearview mirror.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the interior mirror horizontal position data parameter.

Does the scan tool indicate that the interior mirror horizontal position data parameter is greater than the specified value?

4.6 V

Go to Step 11

Go to Step 21

11

  1. Turn OFF the ignition
  2. Connect a 3 amp fused jumper wire between the horizontal signal circuit of the inside rearview mirror and the low reference circuit of the inside rearview mirror.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the interior mirror horizontal position data parameter.

Does the scan tool indicate that the interior mirror horizontal position data parameter is less than the specified value?

0.16 V

Go to Step 12

Go to Step 22

12

  1. Turn OFF the ignition
  2. Disconnect the fused jumper wire.
  3. Connect a 3 amp fused jumper wire between the 5 volt reference circuit of the inside rearview mirror and the horizontal signal circuit of the inside rearview mirror.
  4. Turn ON the ignition, with the engine OFF.
  5. With a scan tool, observe the interior mirror horizontal position data parameter.

Does the scan tool indicate that the interior mirror horizontal position data parameter is greater than the specified value?

4.6 V

Go to Step 20

Go to Step 19

13

  1. Turn OFF the ignition.
  2. Disconnect the harness connector of the inside rearview mirror.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the interior mirror vertical position data parameter.

Does the scan tool indicate that the interior mirror vertical position data parameter is greater than the specified value?

4.6 V

Go to Step 14

Go to Step 21

14

  1. Turn OFF the ignition
  2. Connect a 3 amp fused jumper wire between the vertical signal circuit of the inside rearview mirror and the low reference circuit of the inside rearview mirror.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the interior mirror vertical position data parameter.

Does the scan tool indicate that the interior mirror vertical position data parameter is less than the specified value?

0.16 V

Go to Step 15

Go to Step 22

15

  1. Turn OFF the ignition
  2. Disconnect the fused jumper wire.
  3. Connect a 3 amp fused jumper wire between the 5 volt reference circuit of the inside rearview mirror and the vertical signal circuit of the inside rearview mirror.
  4. Turn ON the ignition, with the engine OFF.
  5. With a scan tool, observe the interior mirror vertical position data parameter.

Does the scan tool indicate that the interior mirror horizontal position data parameter is greater than the specified value?

4.6 V

Go to Step 20

Go to Step 19

16

Test the mirror up circuit of the inside rearview mirror for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 28

Go to Step 25

17

Test the mirror right circuit of the inside rearview mirror for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 28

Go to Step 25

18

Test the mirror motor control circuit of the inside rearview mirror for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 28

Go to Step 25

19

Test the 5 volt reference circuit of the inside rearview mirror for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 28

Go to Step 25

20

Test the 5 volt reference circuit of the inside rearview mirror for a short to voltage or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 28

Go to Step 24

21

Test the signal circuit of the inside rearview mirror for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 28

Go to Step 25

22

Test the signal circuit of the inside rearview mirror for a short to voltage, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 28

Go to Step 23

23

Test the low reference circuit of the inside rearview mirror for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 28

Go to Step 25

24

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 in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 28

Go to Step 26

25

Inspect for poor connections at the harness connector of the MSM. 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 28

Go to Step 27

26

Replace the inside rearview mirror. Refer to Inside Rearview Mirror Replacement .

Did you complete the replacement?

--

Go to Step 28

--

27

Important: Perform the set up procedure for the MSM.

Replace the MSM. Refer to Memory Seat Control Module Replacement in Seats.

Did you complete the replacement?

--

Go to Step 28

--

28
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK