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 B1825 01: Seat Recline Position Sensor Circuit Short to Battery
DTC B1825 06: Seat Recline Position Sensor Circuit Short to Ground or Open
DTC B1825 5A: Seat Recline Position Sensor Circuit Plausibility Failure
DTC B1850 01: Left Front Seat Lumbar Horizontal Position Sensor Circuit Short to Battery
DTC B1850 06: Left Front Seat Lumbar Horizontal Position Sensor Circuit Short to Ground or Open
DTC B1850 5A: Left Front Seat Lumbar Horizontal Position Sensor Circuit Plausibility Failure
DTC B1860 01: Left Front Seat Lumbar Vertical Position Sensor Circuit Short to Battery
DTC B1860 06: Left Front Seat Lumbar Vertical Position Sensor Circuit Short to Ground or Open
DTC B1860 5A: Left Front Seat Lumbar Vertical Position Sensor Circuit Plausibility Failure
DTC B2355 01: Left Seat Front Vertical Position Sensor Circuit Short to Battery
DTC B2355 06: Left Seat Front Vertical Position Sensor Circuit Short to Ground or Open
DTC B2355 5A: Left Seat Front Vertical Position Sensor Circuit Plausibility Failure
DTC B2365 01: Left Seat Rear Vertical Position Sensor Circuit Short to Battery
DTC B2365 06: Left Seat Rear Vertical Position Sensor Circuit Short to Ground or Open
DTC B2365 5A: Left Seat Rear Vertical Position Sensor Circuit Plausibility Failure
DTC B2375 01: Left Seat Assembly Horizontal Position Sensor Circuit Short to Battery
DTC B2375 06: Left Seat Assembly Horizontal Position Sensor Circuit Short to Ground or Open
DTC B2375 5A: Left Seat Assembly Horizontal Position Sensor Circuit Plausibility Failure

### 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 | --
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 Description

The position sensor that sets this diagnostic trouble code (DTC) is either attached to the seat directional motor drive cable or directly to the motor it monitors. It receives a 5-volt reference and a low reference from the memory seat module (MSM). The sensor sends a voltage signal that varies with the movement of the seat through the signal circuit to the MSM. Then based on this voltage signal, the MSM determines the position of the seat.

### Conditions for Running the DTC

The memory seat module must be powered.

### Conditions for Setting the DTC

#### B1825 01, B1850 01, B1860 01, B2355 01, B2365 01, B2375 01

If the MSM sees the analog input from this sensor is greater than 4.75 volts, the sensor will be considered out of range and the MSM will set this DTC.

#### B1825 06, B1850 06, B1860 06, B2355 06, B2365 06, B2375 06

If the MSM sees the analog input from this sensor is less than 0.22 volts, the sensor will be considered out of range and the MSM will set this DTC.

#### B1825 5A, B1850 5A, B1860 5A, B2355 5A, B2365 5A, B2375 5A

This DTC will set, if the MSM is controlling a motor in one direction and its position sensor is tracking the motor in the opposite direction. The sensor is either mounted or wired incorrectly, or the polarity of the motor control circuits are reversed.

### Action Taken When the DTC Sets

The MSM disables the memory recall and easy exit/entry action commands of the motor monitored by the sensor. The motor will respond to manual positioning commands.

### Conditions for Clearing the DTC

• | The current DTC will clear and set to history, when the MSM sees the analog input from the sensor as between 0.22-4.75 volts 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 codes will set.

• | If the 5-volt reference circuit is shorted to ground, multiple codes will set.

• | If the sensor ground circuit is open, multiple codes will set.

### Reference Information

#### Schematic Reference

Driver Seat Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

• | Power Seats System 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 Verification

Ignition ON, observe all scan tool Memory Seat Module driver seat and lumbar sensor parameters. The readings should be between 0.22 volts and 4.75 volts and change while adjusting seat and lumbar positions.

### Circuit/System Testing

#### B1825 01 or B1825 06

1. Ignition OFF, disconnect the harness connector at the seat recline position sensor.
2. Test for less than 2 ohms between the low reference circuit terminal 3 and ground.

⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the MSM.

3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 1 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. Verify the scan tool Driver Seat Recline Sensor parameter is less than 1 volt.

⇒ | If greater than the specified range, test the signal circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the MSM.

5. Install a 3A fused jumper wire between the signal circuit terminal 2 and the 5-volt reference circuit terminal 1. Verify the scan tool Driver Seat Recline Sensor parameter is greater than 4.75 volts.

⇒ | If less than the specified value, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.

6. If all circuits test normal, test or replace the seat recline position sensor.

#### B2355 01, B2355 06, B2365 01, B2365 06, B2375 01 or B2375 06

1. Ignition OFF, disconnect the harness connector at the appropriate seat position sensor.
2. Test for less than 2 ohms between the low reference circuit terminal 3 and ground.

⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the MSM.

3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 1 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. Verify the appropriate scan tool driver seat sensor parameter listed below is less than 1 volt.

• | Driver Seat Front Vertical Sensor

• | Driver Seat Rear Vertical Sensor

• | Driver Seat Horizontal Sensor

⇒ | If greater than the specified range, test the signal circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the MSM.

5. Install a 3A fused jumper wire between the signal circuit terminal 2 and the 5-volt reference circuit terminal 1. Verify the appropriate scan tool driver seat sensor parameter listed below is greater than 4.75 volts.

• | Driver Seat Front Vertical Sensor

• | Driver Seat Rear Vertical Sensor

• | Driver Seat Horizontal Sensor

⇒ | If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.

6. If all circuits test normal, test or replace the appropriate seat position sensor.

#### B1850 01, B1850 06, B1860 01 or B1860 06

1. Ignition OFF, disconnect the harness connector at the appropriate lumbar motor.
2. Test for less than 2 ohms between the low reference circuit terminal 2 and ground.

⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the MSM.

3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 4 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. Verify the appropriate scan tool lumbar sensor parameter listed below is less than 1 volt.

• | Lumbar Horizontal Sensor

• | Lumbar Vertical Sensor

⇒ | If greater than the specified range, test the signal circuit terminal 3 for a short to voltage. If the circuit tests normal, replace the MSM.

5. Install a 3A fused jumper wire between the signal circuit terminal 3 and the 5-volt reference circuit terminal 1. Verify the appropriate scan tool lumbar sensor parameter listed below is greater than 4.75 volts.

• | Lumbar Horizontal Sensor

• | Lumbar Vertical Sensor

⇒ | If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.

6. If all circuits test normal, test or replace the lumbar position sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Front Seat Lumbar Support Replacement

• | Front Seat Recliner Actuator Motor Replacement

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