Memory Seat Feature Inoperative

Memory Seat Feature Inoperative

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information






Circuit/System Description

Battery positive voltage is supplied to the memory function switch from the driver door switch (DDS). When a memory switch is pressed, battery voltage is applied through the switch contacts, a series of resistors, and thorough the memory switch signal circuit to the DDS. The door control module then sends a message via the GMLAN serial data line to the memory seat module (MSM) indicating the memory recall request. The MSM then commands the appropriate seat motors to move to the pre-recorded seat positions stored in memory in response to the switch input.

Circuit/System Verification

1. Verify that all manual power seat and lumbar functions operate as described in the description and operation.
2. Verify that memory positions for driver 1 and driver 2 have been recorded to memory, by observing the scan tool Driver Position Module, Memory Data 1 and Memory Data 2 parameters.

Circuit/System Testing

1. Ignition ON, verify the scan tool Memory Recall Switches parameter is approximately 2.74 volts while pressing the memory 1 switch.

^ If the parameter is not the specified value, refer to Memory Switch component test. If the switch tests normal, replace the driver door switch.

2. Verify the scan tool Memory Recall Switches parameter is approximately 1.78 volts while pressing the memory 2 switch.

^ If the parameter is not the specified value, replace the memory switch.

3. Verify the scan tool Memory Recall Switches parameter is approximately 0.96 volt while pressing the EXIT switch.

^ If the parameter is not the specified value, replace the memory switch.

4. If all circuits test normal, replace the memory seat module.

Component Testing

Memory Switch

1. Disconnect the X4 harness connector at driver door switch.
2. Test for infinite resistance between the memory switch signal circuit terminal 5 and the switch supply voltage circuit terminal 14.

^ If not infinite, replace the memory switch.

3. Test the resistance between terminal 14 and terminal 5 while pressing the memory 1, memory 2, and EXIT buttons. Compare the resistance readings to the values in the Memory Switch Values table below.

^ If the resistance is not within the specified range, replace the memory switch.






Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Driver Seat Adjuster Memory Switch Replacement (Crew Cab)