For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | 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 | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
5-Volt Reference | B1395 02, B1825 06, B1850 06, B1860 06, B2355 06, B2365 06, B2375 06, B2860 06, B2880 06 | B1825 06, B1850 06, B1860 06, B2355 06, B2365 06, B2375 06, B2860 06, B2880 06 | B1395 05, B1825 01, B1850 01, B1860 01, B2355 01, B2365 01, B2375 01, B2860 01, B2880 01 | B1825 5A, B1850 5A, B1860 5A, B2355 5A, B2365 5A, B2375 5A, B2860 5A, B2880 5A
Front Vertical Position Sensor Signal | B2355 06 | B2355 06 | B2355 01 | --
Horizontal Position Sensor Signal | B2375 06 | B2375 06 | B2375 01 | --
Lumbar Horizontal Position Sensor Signal | B1850 06 | B1850 06 | B1850 01 | --
Lumbar Vertical Position Sensor Signal | B1860 06 | B1860 06 | B1860 01 | --
Rear Vertical Position Sensor Signal | B2365 06 | B2365 06 | B2365 01 | --
Recline Position Sensor Signal | B1825 06 | B1825 06 | B1825 01 | --
Steering Column Telescope Motor Signal | B2860 06 | B2860 06 | B2860 01 | --
Steering Column Tilt Motor Signal | B2880 06 | B2880 06 | B2880 01 | --
Memory Seat/Mirror Sensor Low Reference | -- | B1825 01, B1850 01, B1860 01, B2355 01, B2365 01, B2375 01, B2860 01, B2880 01 | -- | B1825 5A, B1850 5A, B1860 5A, B2355 5A, B2365 5A, B2375 5A, B2860 5A, B2880 5A

### Circuit/System Description

The memory seat module (MSM) supplies a 5-volt reference voltage to the driver seat and tilt/telescoping 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 tilt/telescopic steering.

### Conditions for Running the DTC

The memory seat module must be powered.

### Conditions for Setting the DTC

The following conditions exist for more than 1 second:

#### B1395 02

The reference voltage is less than 4.8 volts.

#### B1395 05

The reference voltage is greater than 5.2 volts.

### Action Taken When the DTC Sets

All memory recall functions will be disabled.

### Conditions for Clearing the DTC

• | The current DTC will clear 3 seconds after the reference voltage returns to 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

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

### Reference Information

#### Schematic Reference

• | Driver Seat Schematics

• | Tilt/Telescoping Steering Column Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Memory Seats Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References 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 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.

• | Horizontal position sensor terminal 2

• | Front vertical position sensor terminal 2

• | Rear vertical position sensor terminal 2

• | Recline position sensor terminal 2

• | Lumbar horizontal position sensor terminal 3

• | Lumbar vertical position sensor terminal 3

• | Tilt position sensor terminal A X2

• | Telescope position sensor terminal D 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 after completing the diagnostic procedure.

• | Front Seat Lumbar Support Replacement

• | Front Seat Recliner Actuator Motor Replacement

• | Steering Column Replacement

• | Control Module References for MSM replacement, setup, and programming