GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2007 🢒 Rendezvous - FWD 🢒 DTC 🢒 DTC B1735, B1740, B1745, B1750, B1755, B1760, B1815, or B1820

Circuit Description

The seat adjuster switch is supplied a 12-volt reference circuit by the memory seat module (MSM). When a seat adjuster switch is pressed the signal circuit is closed to the 12-volt reference circuit. Closing the signal circuit to the 12-volt reference circuit pulls the signal circuit high indicating to the MSM the switch status is active.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC B1735 Driver Seat Front Up Switch Circuit
    • DTC B1740 Driver Seat Front Down Switch Circuit
    • DTC B1745 Driver Seat Rear Up Switch Circuit
    • DTC B1750 Driver Seat Rear Down Switch Circuit
    • DTC B1755 Driver Seat Assembly Forward Switch Circuit
    • DTC B1760 Driver Seat Assembly Rearward Switch Circuit
    • DTC B1815 Driver Seat Recline Forward Switch Circuit
    • DTC B1820 Driver Seat Recline Rearward Switch Circuit

Conditions for Running the DTC

The system voltage must be between 9-16 volts.

Conditions for Setting the DTC

A seat adjuster switch input to the MSM is active for more than 30 seconds.

Action Taken When the DTC Sets
    • The MSM will ignore the switch input for which a current status DTC is set.
    • When the fault is no longer present a history status DTC will be stored, and switch 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. This step tests the seat adjuster switch for an internal fault.

  2. When the seat adjuster switch is disconnected the faulty switch signal circuit will be isolated.

Step

Action

Yes

No

Schematic Reference: Driver Seat Schematics

Connector End View Reference: 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. Verify that the DTC is current.

Is the DTC current?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3

  1. Disconnect the seat adjuster switch connector.
  2. With a scan tool, observe the current DTCs.

Is the DTC current?

Go to Step 4

Go to Step 5

4

Test the switch signal circuit indicated in the previous step for a short to voltage. Refer to Circuit Testing and to Wiring Repairs.

Did you find and correct the condition?

Go to Step 9

Go to Step 6

5

Inspect and repair any damage to the seat adjuster switch connector and terminals which may cause the condition. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs.

Did you find and correct the condition?

Go to Step 9

Go to Step 7

6

Inspect and repair any damage to the memory seat module (MSM) connector and terminals which may cause the condition. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs.

Did you find and correct the condition?

Go to Step 9

Go to Step 8

7

Replace the seat adjuster switch. Refer to Power Seat Switch Replacement .

Did you complete the replacement?

Go to Step 9

--

8

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

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 within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK