B2376

DTC B1826, B1851, B1861, B2356, B2366, or B2376

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptors
DTC B1826
- Driver Seat Recline Position Sensor Circuit Range/Performance

DTC B2356
- Driver Seat Front Vertical Position Sensor Circuit Range/Performance

DTC B2366
- Driver Seat Rear Vertical Position Sensor Circuit Range/Performance

DTC B2376
- Driver Seat Horizontal Position Sensor Circuit Range/Performance




Diagnostic Fault Information






Circuit/System Description

The front vertical, rear vertical, horizontal, and recline seat position sensors are potentiometers that are either attached directly to the motor transmission cable or are an internal part of the motor. The memory seat module (MSM) supplies a 5-volt reference voltage through the 5-volt reference circuit and ground through the low reference circuit to the respective seat position sensors. When the motor or cable rotates, the resistance of the potentiometer varies changing the feedback voltage of the position sensor signal circuit. This voltage varies from 0.25-4.75 volts. The MSM monitors this voltage signal to determine the position of the seat. When the MSM detects that one of the seat position sensor signal circuits is out of the voltage range of 0.25-4.75 volts, a DTC will be set for that signal circuit.


Conditions for Running the DTC

* DTC B1327 must not be present.
* Battery voltage must be between 9-16 volts.



Conditions for Setting the DTC

These DTCs will set when the MSM receives a signal form a seat position sensor that a motor being driven in a commanded direction changes by more than 10 counts or 0.2 volts in the wrong direction. The signal mismatches what the MSM is commanding the motors to perform.


Actions Taken When the DTC Sets

The motor associated with the fault will be disabled for memory functions.


Conditions for Clearing the DTCs

* The condition responsible for setting the DTC no longer exists.
* A history DTC will clear once 50 consecutive malfunction-free ignition cycles have occurred.



Diagnostic Aids

The memory seat module (MSM) is also referred to as the driver position module (DPM) in certain scan tool menus.


Reference Information
Schematic Reference

Driver Seat Schematics (Driver Seat Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Memory Seats Description and Operation (Memory Seats Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning)


Circuit/System Testing

1. Ignition OFF, disconnect the X1 harness connectors at the driver seat adjuster motor assembly and the driver seat recline motor.
2. Verify that the seat motor wiring circuits for all seat position motors are in the correct harness connector cavities.

• If the wires are not in the correct cavities, make the necessary changes.

3. Connect the X1 harness connectors at the driver seat adjuster motor assembly and the driver seat recline motor.
4. Disconnect the X2, X3, and X4 harness connectors at the driver seat adjuster motor assembly.
5. Verify that the seat motor position sensor wiring circuits for all seat position sensors are in the correct harness connector cavities.

• If the wires are not in the correct cavities, make the necessary changes.

6. Disconnect the X2 harness connector at the driver seat recline motor.
7. Verify that the seat recline motor position sensor wiring circuits are in the correct harness connector cavities.
8. Disconnect the harness connectors at the driver seat adjuster switch.
9. Verify that the seat adjuster switch wiring circuits are in the correct harness connector cavities.

• If the wires are not in the correct cavities, make the necessary changes.

10. If all circuits test normal, replace the MSM.



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.


Control Module References (Programming and Relearning) for MSM replacement, setup, and programming