Power Seats

DTC B1395

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 B1395 02
- Device Voltage Reference Output Circuit Shorted to Ground

DTC B1395 05
- Device Voltage Reference Output Circuit Shorted 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 horizontal, front vertical, rear vertical, recline, and lumbar horizontal 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.


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 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 the normal operating range and the ignition is cycled OFF then back to ACC or RUN.
* The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.



Diagnostic Aids

* All 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 DTC.
* An internal short to ground in one of the position sensors may set this DTC.



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) 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 and Column Info. The readings should be 0.0 volts.

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

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 4.8 volts, 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 4.8 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the MSM.

4. Connect each position sensor associated with the 5 volt reference circuit one at a time while monitoring the measured voltage. The voltage reading should remain within the specified range.

• If not the within specified range, replace the 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 Recliner Actuator Motor Replacement (Front Seat Recliner Actuator Motor Replacement)
* Control Module References (Programming and Relearning) for memory seat module replacement, setup, and programming