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Power Seats




DTC B1395

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 B1395 02
- Device Voltage Reference Output Circuit Short to Ground

DTC B1395 05
- Device Voltage Reference Output Circuit Short to Battery or Open

Diagnostic Fault Information





Circuit/System Description

The memory seat module (MSM) supplies a 5-volt reference voltage to the driver seat position sensors, lumbar position sensors, passenger seat lumbar vertical position sensor, and the steering column position sensors. The MSM monitors this reference voltage to ensure the accuracy of the voltages being returned from the sensors. If the voltage exceeds the normal operating range, errors will occur in the memory recall operations of the seat and steering column.

Conditions for Running the DTC

The MSM must be powered.

Conditions for Setting the DTC

B1395 02

The reference voltage drops below 4.8 volts for more than 300 mS.

B1395 05

The reference voltage exceeds 5.2 volts for more than 300 mS.

Action Taken When the DTC Sets

All memory recall and seat massage functions will be disabled.

Conditions for Clearing the DTC

* The current DTC will clear and set the code to history 3 seconds after the reference voltage returns to normal operating range and the power mode changes to OFF then back to ACC or RUN.
* The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Diagnostic Aids

* The scan tool may reference the Memory Seat Module (MSM) as the Driver Position Module.
* All seat, lumbar, and tilt/telescoping steering column position sensors use common ground and 5-volt reference circuits.
* If the 5-volt reference circuit is shorted to voltage multiple position sensor codes will set.
* If the 5-volt reference circuit is shorted to ground multiple position sensor codes will set.
* A short to voltage on one of the position sensor signal circuits may set this code.
* An internal short to ground in one of the position sensors may set this code.

Reference Information
Schematic Reference

* Driver Seat Schematics (Driver Seat Schematics)
* Passenger Seat Schematics (Passenger Seat Schematics)
* Tilt/Telescoping Steering Column Schematics (Tilt/Telescoping Steering Column Schematics)

Connector End View Reference

Component Connector End Views (Connector Views)
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 harness connector for all position sensors connected to the 5-volt reference circuit.
2. Ignition ON, observe all scan tool sensor parameters for Seat 1 Info, Seat 2 Info, and Column Info. The readings should be 0.0 volts.

• If greater than the specified value, test the appropriate signal circuits listed below for a short to voltage. If the circuit tests normal, replace the MSM.

* Driver seat horizontal position sensor terminal 3 X2
* Driver seat front vertical position sensor terminal 1 X2
* Driver seat rear vertical position sensor terminal 5 X2
* Driver seat recline position sensor terminal 2 X2
* Driver seat lumbar horizontal position sensor terminal 2
* Driver seat lumbar vertical position sensor terminal 2
* Passenger seat lumbar vertical position sensor terminal B X353
* Tilt position sensor terminal C X2
* Telescope position sensor terminal C X2

3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit at any one of the position sensors and ground.

• If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.
• If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the MSM.

4. Connect each position sensor one at a time and verify that the DTC does not set as current.

• If the DTC sets as current, replace the appropriate position sensor.

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

Repair Instructions

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

* Front Seat Adjuster Replacement (Front Seat Adjuster Replacement)
* Driver or Passenger Seat Lumbar Support Replacement (w/AL2) (Driver or Passenger Seat Lumbar Support Replacement (W/AL2))Driver or Passenger Seat Lumbar Support Replacement (w/AM3) (Driver or Passenger Seat Lumbar Support Replacement (W/AM3))
* Front Seat Recliner Position Sensor Replacement (Service and Repair)
* Tilt Motor Replacement (Service and Repair)
* Steering Column Telescope Actuator Replacement (Steering Column Telescope Actuator Replacement)
* Control Module References (Programming and Relearning) for MSM replacement, setup, and programming

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