SAAB WIS ONLINE

DTC B1735, B1740, B1745, B1750, B1755, B1760, B1815, or B1820

DTC B1735, B1740, B1745, B1750, B1755, B1760, B1815, or B1820

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

Driver Seat Front Up Switch Circuit Short to Ground

DTC B1740 02

Driver Seat Front Down Switch Circuit Short to Ground

DTC B1745 02

Driver Seat Rear Up Switch Circuit Short to Ground

DTC B1750 02

Driver Seat Rear Down Switch Circuit Short to Ground

DTC B1755 02

Driver Seat Assembly Forward Switch Circuit Short to Ground

DTC B1760 02

Driver Seat Assembly Rearward Switch Circuit Short to Ground

DTC B1815 02

Driver Seat Recline Forward Switch Circuit Short to Ground

DTC B1820 02

Driver 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 seat memory control module supplies a reference voltage to each signal circuit of the driver seat switch. When the power seat switches are pressed, the appropriate signal circuit from the seat memory control module is pulled low through the switch contacts indicating the power seat command. The seat memory control 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 seat memory control 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 the scan tool Seat Memory Control Module seat switch parameters listed below while pressing and releasing the appropriate seat directional switch. The readings should change between Inactive and Forward/Rearward or UP/Down.


Driver Seat Cushion Front Vertical Switch

Driver Seat Cushion Rear Vertical Switch

Driver Seat Horizontal Switch

Driver Seat Back Switch


Circuit/System Testing


1. Ignition OFF, disconnect the harness connector at the S64D driver 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 Vertical Switch

Driver Seat Horizontal Switch

Driver Seat Back Switch

3. 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 seat memory control 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

4. If all circuits test normal, test or replace the S64D driver seat aduster switch.


Component Testing


1. Ignition OFF, disconnect the harness connector at the S64D driver 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

3. If not the specified value, replace the S64D driver seat adjuster switch.

4. Test for less than 2 Ω between the ground terminal E and each signal terminal listed below with the appropriate 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

5. If greater than the specified value, replace the S64D driver seat adjuster switch.


Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.


Driver or Passenger Seat Adjuster Switch Replacement (Driver/Passenger Seat 4-Way Hybrid)

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