GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2005 🢒 STS 🢒 Body 🢒 Seats 🢒 DTC B1335

Circuit Description

Battery positive voltage is supplied to the memory seat module (MSM)/driver position module (DPM) from the seats circuit breaker located in the left rear fuse block. When commanded, this voltage is used by the MSM/DPM to power the seat motors through the motor control circuits. During memory recall functions and manual seat functions, the driven motor current is monitored through the motor control circuits by the MSM/DPM. When an overcurrent condition is detected, the MSM/DPM disables the seat motors in order to protect the internal MSM/DPM circuitry.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B1335 Device Power 3 Circuit Range/Performance

Conditions for Running the DTC

The MSM/DPM monitors for overcurrent only when the seat motors are active.

Conditions for Setting the DTC

The MSM/DPM will set DTC B1335 when the measured current exceeds 81 amps for 100 milliseconds.

Action Taken When the DTC Sets
    • All memory recalls in progress are aborted.
    • The MSM/DPM will not respond to manual movements of the affected motor.

Conditions for Clearing the DTC

The MSM/DPM does not detect an overcurrent condition during seat movement.

Diagnostic Aids

The MSM is also known as the DPM for this vehicle.

Test Description

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

  1. This test determines which directional motor exhibits excessive current.

    2.

  2. This test determines if the suspect motor has an internal short to ground.

    3.

  3. This test verifies the repair.

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 in Vehicle DTC Information

2

  1. Install a scan tool.
  2. Clear DTC B1335.
  3. Turn ON the ignition, with the engine OFF.
  4. Operate the seat switch in both directions for each directional motor.
  5. With a scan tool, observe the Diagnostic Trouble Codes (DTC) in the Seats data list after operating each seat motor.

Did the scan tool display DTC B1335 as a current or history DTC for any of the seat motors?

Go to Step 3

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

3

  1. Clear DTC B1335.
  2. Disconnect the suspect motor harness connector.
  3. Operate the suspect motor switch in both directions.

Did the driver position module set DTC B1335 as a current or history DTC?

Go to Step 4

Go to Step 5

4

Test the motor control circuits of the suspect motor 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 9

Go to Step 6

5

Inspect for poor connections at the harness connector of the suspect seat motor. 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 9

Go to Step 7

6

Inspect for poor connections at the harness connector of the memory seat module (MSM)/driver position module (DPM). 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 9

Go to Step 8

7

Replace the suspect seat motor. Refer to Front Seat Adjuster Replacement .

Did you complete the replacement?

Go to Step 9

--

8

Replace the MSM/DPM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming .

Did you complete the replacement?

Go to Step 9

--

9

  1. Clear the DTCs using the scan tool.
  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