GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2002 🢒 Montana - 4WD 🢒 DTC 🢒 DTC B1770, B1775, B1780, B1785, B1790, B1805, or B2415

Circuit Description

The seat adjuster motors are controlled by the memory seat module through the adjuster motor control circuits. The memory seat module also monitors current flow through the adjuster motor control circuits. In an inactive state the control circuits are closed to ground within the memory seat module. In an active state the appropriate adjuster motor control circuit is switched to battery voltage within the memory seat module. The direction of the adjuster motor rotation is determined by which of the control circuits is switched to battery voltage while the other remains grounded.

Conditions for Running the DTC

The system voltage must be between 9.0 and 16.0 volts.

Conditions for Setting the DTC

The adjuster motor control circuit current monitored by the memory seat module is high, low, or open.

Action Taken When the DTC Sets
    • The memory seat module will disable the seat adjuster motor for which a current status DTC is set.
    • When the fault is no longer present a history status DTC will be stored, and adjuster motor operation will be restored.

Conditions for Clearing the DTC
    • The DTC will be current for as long as the fault is present.
    • When the fault is no longer present the DTC will be a history status code.
    • The history DTC will be cleared after 100 error free ignition cycles, or by using the scan tool clearing DTCs feature.

Test Description

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

  1. Verify that the DTC is current or history by attempting to operate the seat adjuster motor for which the code is set.

    2.

  2. Tests the adjuster motor control circuits for proper operation.

Step

Action

Yes

No

Schematic Reference: Memory Seats Schematics

Connector End View Reference: Power Seat Connector End Views

1

Did you perform the Power Seat Systems Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Power Seat Systems

2

  1. Install a scan tool.
  2. With a scan tool, operate the seat adjuster motor through the full range of adjustment in both directions.

Does the seat adjuster motor operate through the full range of adjustment?

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

Go to Step 3

3

  1. Disconnect the seat adjuster motor assembly connector.
  2. Connect a test lamp between the affected adjuster motor control circuit terminals in the seat harness connector.
  3. With a scan tool, command the adjuster motor active in both directions.

Does the test lamp turn ON and OFF with each command?

Go to Step 5

Go to Step 4

4

Test and repair the adjuster motor control circuits for the following conditions:

    • Short to ground
    • Open or high resistance
    • Short to voltage

Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 6

5

Inspect for poor connections at the adjuster motor connector. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 7

6

Inspect for poor connections at the harness connector of the memory seat module. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 8

7

Replace the seat adjuster motor assembly. Refer to Power Seat Adjuster Mechanism Replacement .

Did you complete the replacement?

Go to Step 9

--

8

Replace the memory seat module. Refer to Memory Seat Control Module Replacement .

Did you complete the replacement?

Go to Step 9

--

9
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the system in order to verify the repair.

Does the DTC reset?

Go to Step 2

System OK