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 B1735 02: Seat Front Up Switch Circuit Short to Ground
DTC B1740 02: Seat Front Down Switch Circuit Short to Ground
DTC B1745 02: Seat Rear Up Switch Circuit Short to Ground
DTC B1750 02: Seat Rear Down Switch Circuit Short to Ground
DTC B1755 02: Seat Assembly Forward Switch Circuit Short to Ground
DTC B1760 02: Seat Assembly Rearward Switch Circuit Short to Ground
DTC B1815 02: Seat Recline Forward Switch Circuit Short to Ground
DTC B1820 02: Seat Recline Rearward Switch Circuit Short to Ground

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Front Vertical Up Switch Signal | B1735 02, B1740 02, B1745 02, B1750 02, B1755 02, B1760 02, B1815 02, B1820 02 | 1 | -- | --
Front Vertical Down Switch Signal | B1735 02, B1740 02, B1745 02, B1750 02, B1755 02, B1760 02, B1815 02, B1820 02 | 1 | -- | --
Rear Vertical Up Switch Signal | B1735 02, B1740 02, B1745 02, B1750 02, B1755 02, B1760 02, B1815 02, B1820 02 | 1 | -- | --
Rear Vertical Down Switch Signal | B1735 02, B1740 02, B1745 02, B1750 02, B1755 02, B1760 02, B1815 02, B1820 02 | 1 | -- | --
Horizontal Forward Switch Signal | B1735 02, B1740 02, B1745 02, B1750 02, B1755 02, B1760 02, B1815 02, B1820 02 | 1 | -- | --
Horizontal Rearward Switch Signal | B1735 02, B1740 02, B1745 02, B1750 02, B1755 02, B1760 02, B1815 02, B1820 02 | 1 | -- | --
Recline Forward Switch Signal | B1735 02, B1740 02, B1745 02, B1750 02, B1755 02, B1760 02, B1815 02, B1820 02 | 1 | -- | --
Recline Rearward Switch Signal | B1735 02, B1740 02, B1745 02, B1750 02, B1755 02, B1760 02, B1815 02, B1820 02 | 1 | -- | --
1. Power seat inoperative

### Circuit/System Description

The memory seat module supplies a reference voltage to each signal circuit of the seat adjuster switch. When the power seat switches are pressed, the appropriate signal circuit from the memory seat module is pulled low through the switch contacts indicating the power seat command. The memory seat module then commands the driver seat to move in response to the switch signals.

### Conditions for Running the DTC

• | DTC B1325 must not be present.

• | Module battery voltage must be between 9 - 16 V.

### Conditions for Setting the DTC

• | If a seat switch circuit is active in one direction and the switch for the opposite direction is pressed, this DTC will set.

• | A short to ground on a switch signal circuit.

### Action Taken When the DTC Sets

• | A motor output driven in response to a switch considered failed, is deactivated for both directions.

• | All memory recall commands are ignored.

• | The memory seat module will respond to any other switch signal that has not set a DTC.

### Conditions for Clearing the DTC

• | The current DTC will clear and set the code to history, when the fault is no longer present and the ignition is cycled OFF then back to ACC or RUN.

• | The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.

### Diagnostic Aids

• | If one of the switch signal circuits is shorted to ground, multiple codes will set.

• | If a switch is stuck in one direction and the switch is pressed in the opposite direction, a single code will set.

### Reference Information

#### Schematic Reference

Driver Seat 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 Verification

Ignition ON, observe all scan tool K40 Memory Seat Module seat switch parameters while pressing and releasing each seat directional switch. The readings should change between Inactive and Forward/Rearward or UP/Down.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the S64D seat adjuster switch.
2. Verify that all scan tool driver seat switch parameters listed below are Inactive:

• | Driver Seat Cushion Front Vertical Switch

• | Driver Seat Cushion Rear Switch

• | Driver Seat Horizontal Switch

• | Driver Seat Back Switch

⇒ | If not the specified value, test the appropriate signal circuit listed below for a short to ground. If the circuit tests normal, replace the K40 memory seat module.

• | Front vertical upward switch terminal A (LHD)

• | Front vertical upward switch terminal K (RHD)

• | Front vertical downward switch terminal K (LHD)

• | Front vertical downward switch terminal A (RHD)

• | Rear vertical upward switch terminal F (LHD)

• | Rear vertical upward switch terminal J (RHD)

• | Rear vertical downward switch terminal J (LHD)

• | Rear vertical downward switch terminal F (RHD)

• | Horizontal forward switch terminal D

• | Horizontal rearward switch terminal C

• | Recline forward switch terminal H

• | Recline rearward switch terminal G

3. If all circuits test normal, test or replace the K64D seat adjuster switch.

### Component Testing

1. Ignition OFF, disconnect the harness connector at the S64D seat adjuster switch.
2. Test for infinite resistance between the ground terminal E and each seat direction signal terminal listed below with the switch in the open position:

• | Front vertical upward switch terminal A (LHD)

• | Front vertical upward switch terminal K (RHD)

• | Front vertical downward switch terminal K (LHD)

• | Front vertical downward switch terminal A (RHD)

• | Rear vertical upward switch terminal F (LHD)

• | Rear vertical upward switch terminal J (RHD)

• | Rear vertical downward switch terminal J (LHD)

• | Rear vertical downward switch terminal F (RHD)

• | Horizontal forward switch terminal D

• | Horizontal rearward switch terminal C

• | Recline forward switch terminal H

• | Recline rearward switch terminal G

⇒ | If not the specified value, replace the S64D seat adjuster switch.

3. Test for less than 2 Ω between the ground terminal E and each signal terminal listed below with the switch in the closed position.

• | Front vertical upward switch terminal A (LHD)

• | Front vertical upward switch terminal K (RHD)

• | Front vertical downward switch terminal K (LHD)

• | Front vertical downward switch terminal A (RHD)

• | Rear vertical upward switch terminal F (LHD)

• | Rear vertical upward switch terminal J (RHD)

• | Rear vertical downward switch terminal J (LHD)

• | Rear vertical downward switch terminal F (RHD)

• | Horizontal forward switch terminal D

• | Horizontal rearward switch terminal C

• | Recline forward switch terminal H

• | Recline rearward switch terminal G

⇒ | If greater than the specified value, replace the S64D seat adjuster switch.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Driver or Passenger Seat Adjuster Switch Replacement

• | Control Module References for K40 memory seat module replacement, setup, and programming