B1745
DTC B1735, B1740, B1745, B1750, B1755, B1760, B1815, or B1820
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions)provides an overview of each diagnostic category.
DTC Descriptors
DTC B1735 01
- Seat Front Up Switch Circuit Short to Battery
DTC B1740 01
- Seat Front Down Switch Circuit Short to Battery
DTC B1745 01
- Seat Rear Up Switch Circuit Short to Battery
DTC B1750 01
- Seat Rear Down Switch Circuit Short to Battery
DTC B1755 01
- Seat Assembly Forward Switch Circuit Short to Battery
DTC B1760 01
- Seat Assembly Rearward Switch Circuit Short to Battery
DTC B1815 01
- Seat Recline Forward Switch Circuit Short to Battery
DTC B1820 01
- Seat Recline Rearward Switch Circuit Short to Battery
Diagnostic Fault Information
Circuit Description
When the power seat switches are pressed, they send a 12 V signal through the switch signal circuits to the memory seat module (MSM). The MSM then commands the driver seat motors to move in response to the switch signals.
Conditions for Running the DTC
The MSM must be powered.
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 voltage 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 MSM will respond to any other switch signal that has not set a DTC.
Conditions for Clearing the DTC
* A current DTC will transition to history 3 seconds after the fault is no longer present 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.
Reference Information
Schematic Reference
Driver Seat Schematics (Driver Seat Schematics)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
* Power Seats System Description and Operation (Power Seats System)
* Memory Seats Description and Operation (Memory Seats)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing For Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
Scan Tool Reference
Control Module References (Programming and Relearning)for scan tool information
Circuit/System Verification
Ignition ON, observe the scan tool Memory Seat Module seat switch parameters while pressing the appropriate seat directional switches. The reading should change between Inactive and Active.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the seat adjuster switch.
2. Ignition ON, verify the scan tool seat switch parameters listed below are Inactive:
* Front Vertical Upward Switch
* Front Vertical Downward Switch
* Rear Vertical Upward Switch
* Rear Vertical Downward Switch
* Horizontal Forward Switch
* Horizontal Rearward Switch
* Recline Forward Switch
* Recline Rearward Switch
• If not the specified value, test the appropriate signal circuit listed below for a short to voltage. If the circuit tests normal, replace the MSM.
* Front vertical upward switch terminal A
* Front vertical downward switch terminal K
* Rear vertical upward switch terminal F
* Rear vertical downward switch terminal J
* 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 seat adjuster switch.
Component Testing
1. Ignition OFF, disconnect the harness connector at the seat adjuster switch.
2. Test for infinite resistance between the B+ terminal E and each signal terminal listed below and with the switch in the open position.
* Front vertical upward switch terminal A
* Front vertical downward switch terminal K
* Rear vertical upward switch terminal F
* Rear vertical downward switch terminal J
* 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 seat adjuster switch.
3. Test for less than 1 Ohms between the B+ terminal E and each signal terminal listed below and with the appropriate switch in the closed position.
* Front vertical upward switch terminal A
* Front vertical downward switch terminal K
* Rear vertical upward switch terminal F
* Rear vertical downward switch terminal J
* 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 range, replace the seat adjuster switch.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Driver Seat Adjuster Switch Replacement (Driver Seat Adjuster Switch Replacement)
* Control Module References (Programming and Relearning)for MSM replacement, setup, and programming