GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2007 🢒 Rendezvous - FWD 🢒 Driver Information and Entertainment 🢒 Cellular, Entertainment, and Navigation 🢒 DTC B1580, B1590, B1610, or B1620

Circuit Description

The memory seat module (MSM) receives inputs from the mirror position sensors during memory 1 and memory 2 recall. The potentiometers in the position sensors vary in resistance as the motors move the mirror. The MSM receives a variable voltage input depending on the resistance of the potentiometer. During memory set, the MSM records the voltages across the mirrors. During memory recall, the MSM moves the mirror motors until the voltage across each potentiometer matches the recorded voltage. During normal operation, the mirror position sensors are checked against out-of-range limits. If the MSM sees the vertical or horizontal position sensor input voltage out of normal range, a DTC B1580, B1590, B1610 or B1620 is set and the mirror outputs are disabled during memory recall.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC B1580 Mirror Horizontal Position Sensor Circuit
    • DTC B1590 Mirror Vertical Position Sensor Circuit
    • DTC B1610 Right Front Mirror Horizontal Position Sensor Circuit
    • DTC B1620 Right Front Mirror Vertical Position Sensor Circuit

Conditions for Running the DTC

Battery input voltage between 9-16 volts.

Conditions for Setting the DTC
    • The outside rearview mirrors vertical or horizontal position sensor input voltage is less than 0.75 volts.
    • The outside rearview mirrors vertical or horizontal position sensor input voltage is greater than 4.50 volts.

Action Taken When the DTC Sets

The MSM will disable the affected motor during memory recall.

Conditions for Clearing the DTC
    • The MSM no longer detects the position sensor failure.
    • DTC will clear after 50 consecutive ignition cycles.

Diagnostic Aids
    • An intermittent malfunction may be caused by an outside rearview mirror that is being operated after reaching the hard stop.
    • If the DTC does not reset after it has been cleared, then the malfunction may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections .

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step tests for an inoperative mirror motor. If the fuse in the jumper opens when you perform this test, the 5-volt reference or mirror position sensor signal circuit is short to ground.

    2.

  2. This step tests for an inoperative mirror assembly. If the fuse in the jumper opens when you perform this test, the 5-volt reference or mirror position sensor signal circuit is short to ground.

    3.

  3. This step tests for a short to ground or an open in the 5-volt reference or mirror position sensor signal circuits.

    4.

  4. This step tests for an inoperative mirror motor.

    5.

  5. This step tests for an inoperative mirror assembly.

    6.

  6. This step tests for a short to voltage in the 5-volt reference or mirror position sensor circuits.

Step

Action

Values

Yes

No

Schematic Reference: Outside Rearview Mirror Schematics

Connector End View Reference: Vehicle Access Connector End Views or Power Seat Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the appropriate Mirror Position Sensor parameters in the memory seat module (MSM) data list.

Does the scan tool indicate that the Mirror Position Sensor parameters are within the specified range?

0.75-4.50 V

Go to Diagnostic Aids

Go to Step 3

3

Does the scan tool indicate that the Mirror Position Sensor parameter is less than the specified range?

0.75 V

Go to Step 4

Go to Step 7

4

  1. Turn OFF the ignition.
  2. Disconnect the appropriate mirror motor.
  3. Connect a 3-amp fused jumper wire between the 5-volt reference circuit and the appropriate signal circuit of the appropriate mirror motor.
  4. Turn ON the ignition, with the engine OFF.

Does the scan tool indicate that the Mirror Position Sensor parameter is greater than the specified range?

4.50 V

Go to Step 15

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Disconnect the fused jumper wire.
  3. Connect the appropriate mirror motor.
  4. Disconnect the appropriate mirror assembly.
  5. Connect a 3-amp fused jumper wire between the 5-volt reference circuit and the appropriate signal circuit of the appropriate mirror assembly.
  6. Turn ON the ignition, with the engine OFF.

Does the scan tool indicate that the Mirror Position Sensor parameter is greater than the specified range?

4.50 V

Go to Step 16

Go to Step 6

6

  1. Disconnect the fused jumper wire.
  2. Measure the voltage between the 5-volt reference circuit of the appropriate mirror motor and the low reference circuit of the appropriate mirror assembly.

Is the voltage less than the specified value?

5 V

Go to Step 10

Go to Step 11

7

Disconnect the appropriate mirror motor.

Does the scan tool indicate that the Mirror Position Sensor parameter is less than the specified range?

0.75 V

Go to Step 15

Go to Step 8

8

Disconnect the appropriate mirror assembly.

Does the scan tool indicate that the Mirror Position Sensor parameter is less than the specified range?

0.75 V

Go to Step 16

Go to Step 9

9

  1. Turn OFF the ignition.
  2. Disconnect the negative battery cable.
  3. Measure the resistance from the low reference circuit of the appropriate mirror assembly to a good ground.

Is the resistance less than the specified value?

5 ohms

Go to Step 12

Go to Step 13

10

Test the 5-volt reference circuit of the appropriate mirror position sensor for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 21

Go to Step 17

11

Test the appropriate mirror position sensor signal circuit for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 21

Go to Step 17

12

Test the 5-volt reference circuit of the appropriate mirror position sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 21

Go to Step 14

13

Test the low reference circuit of the appropriate mirror position sensor for an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 21

Go to Step 17

14

Test the appropriate mirror position sensor signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 21

Go to Step 17

15

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

Did you find and correct the condition?

--

Go to Step 21

Go to Step 18

16

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

Did you find and correct the condition?

--

Go to Step 21

Go to Step 19

17

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

Did you find and correct the condition?

--

Go to Step 21

Go to Step 20

18

Replace the appropriate outside rearview mirror motor. Refer to Outside Rearview Mirror Motor Replacement .

Did you complete the replacement?

--

Go to Step 21

--

19

Replace the appropriate outside rearview mirror. Refer to Power Mirror Replacement .

Did you complete the replacement?

--

Go to Step 21

--

20

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

Did you complete the replacement?

--

Go to Step 21

--

21
  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