GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2005 🢒 DeVille 🢒 Accessories 🢒 Navigation Systems 🢒 DTC B1336

Circuit Description

Battery positive voltage is supplied to the memory seat module (MSM) from the Seats Circuit Breaker located in the left rear fuse block. When commanded, this voltage is used by the MSM 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. When an overcurrent condition is detected, the MSM disables the sea motors in order to protect the internal MSM circuitry.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B1336 Device Power 3 Circuit Range/Performance

Conditions for Running the DTC

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

Conditions for Setting the DTC

The MSM will set DTC B1336 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 will not respond to manual movements of the affected motor.

Conditions for Clearing the DTC

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

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. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the Current Diagnostic Trouble Codes in the Memory Seat Module (MSM) Diagnostic Trouble Code list.
  4. While observing the scan tool for DTCs, operate the seat switch in both directions for each directional motor.

Did the scan tool display DTC B1336 for any of the seat motors?

Go to Step 3

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

3

  1. Disconnect the suspect motor harness connector.
  2. While observing the scan tool for DTCs, operate the suspect motor switch in both directions.

Does the scan tool display DTC B1336?

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 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 9

Go to Step 8

7

Replace the suspect seat motor. Refer to Seat Adjuster Motor Replacement , Front Seat Recliner Actuator Motor Replacement , or Front Seat Lumbar Support Replacement .

Did you complete the replacement?

Go to Step 9

--

8

Replace the MSM. 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