B1760
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
- Driver Seat Front Up Switch Circuit
DTC B1740
- Driver Seat Front Down Switch Circuit
DTC B1745
- Driver Seat Rear Up Switch Circuit
DTC B1750
- Driver Seat Rear Down Switch Circuit
DTC B1755
- Driver Seat Assembly Horizontal Forward Switch Circuit
DTC B1760
- Driver Seat Assembly Horizontal Rearward Switch Circuit
Diagnostic Fault Information
Circuit/System Description
Battery positive voltage is supplied at all times to the seat adjuster switch from the TELE SWITCH/MSM fuse located in the body control module (BCM) fuse block. When a seat adjustment switch is pressed, battery voltage is applied through the switch contacts and the appropriate switch signal circuit 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
* DTC B1327 must not be present.
* Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
B1735, B1740, B1745, B1750, B1755, or B1760
* The MSM will set these DTCs when a short to voltage is detected on a switch signal circuit.
* The MSM will set these DTCs if a seat switch circuit is active in one direction and a switch for the opposite direction is activated.
* The MSM will set these DTCs if a seat adjuster switch is active for 30 seconds after a motor has reached the end of its travel.
Actions Taken When the DTC Sets
* The motor associated with the inoperative switch adjuster signal circuit will be disabled for both directions.
* The memory seat functions for the seat will be disabled.
* The MSM will respond to any other switch adjuster signal that has not set a DTC.
Conditions for Clearing the DTCs
* The condition responsible for setting the DTC no longer exists.
* The history DTC will clear once 50 consecutive fault-free ignition cycles have occurred.
Diagnostic Aids
The memory seat module is also referred to as the Driver Position Module in certain scan tool menus.
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
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)
Circuit/System Verification
Ignition ON, observe all scan tool Driver Position Module seat switch parameters while pressing and releasing each seat directional switch. The readings should change between Inactive and Active.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the driver 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
• If not the specified value, test the appropriate signal circuit terminal listed below for a short to voltage. If the circuit tests normal, replace the MSM.
* Front vertical upward switch terminal B
* Front vertical downward switch terminal D
* Rear vertical upward switch terminal A
* Rear vertical downward switch terminal G
* Horizontal forward switch terminal C
* Horizontal rearward switch terminal F
3. If all circuits test normal, test or replace the driver seat adjuster switch.
Component Testing
Seat Adjuster Switch
1. Ignition OFF, disconnect the harness connector at the seat adjuster switch.
2. Test for infinite resistance between the B+ terminal E and each seat direction signal terminal listed below with the switch in the open position:
* Front vertical upward switch terminal B
* Front vertical downward switch terminal D
* Rear vertical upward switch terminal A
* Rear vertical downward switch terminal G
* Horizontal forward switch terminal C
* Horizontal rearward switch terminal F
• If not the specified value, replace the seat adjuster switch.
3. Test for less than 1 Ohms between the B+ terminal E and each seat direction signal terminal listed below with the appropriate switch in the closed position:
* Front vertical upward switch terminal B
* Front vertical downward switch terminal D
* Rear vertical upward switch terminal A
* Rear vertical downward switch terminal G
* Horizontal forward switch terminal C
* Horizontal rearward switch terminal F
• 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.
* Power Seat Switch Replacement (Power Seat Switch Replacement)
* Control Module References (Programming and Relearning) for MSM replacement, setup, and programming