B2356
DTC B1826, B1851, B1861, B2356, B2366, or B2376
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptors
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, and horizontal 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 V reference voltage through the 5 V 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. 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 V, 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
B2356, B2366, or B2376
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 (0.2 V) 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.
* The history DTC will clear once 50 consecutive fault-free ignition cycles have occurred.
Diagnostic Aids
The memory seat module is also referred to as the Driver Position Module in certain scan tool menus.
Reference Information
Schematic Reference
Driver Seat Schematics (Driver Seat Schematics)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
Memory Seats Description and Operation (Memory Seats)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Testing
1. Ignition OFF, disconnect the X1 harness connector at the driver seat adjuster motor assembly.
2. Verify that the appropriate control circuit terminals listed below are in the correct harness connector cavities:
* Front vertical motor up control terminal C
* Front vertical motor down control terminal D
* Rear vertical motor up control terminal E
* Rear vertical motor down control terminal F
* Seat horizontal motor forward control terminal A
* Seat horizontal motor rearward control terminal B
• If the wires are not in the correct cavities, make the appropriate changes.
3. Disconnect the appropriate X2, X3, X4 harness connector at the driver seat adjuster motor assembly.
4. Verify that the appropriate 5 V reference and low reference circuit terminals listed below are in the correct harness connector cavities:
* Front vertical sensor 5 V reference terminal C
* Front vertical sensor low reference terminal A
* Rear vertical sensor 5 V reference terminal C
* Rear vertical sensor low reference terminal A
* Seat horizontal sensor 5 V reference terminal A
* Seat horizontal sensor low reference terminal C
• If the wires are not in the correct cavities, make the appropriate changes.
5. 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