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 B1830 00: Seat Lumbar Forward Switch CircuitDTC B1835 00: Seat Lumbar Rearward Switch Circuit
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Lumbar Forward Switch Signal | 1 | 1 | B1830 00 | -- |
Lumbar Rearward Switch Signal | 1 | 1 | B1835 00 | -- |
1. Lumbar Support Inoperative | ||||
Circuit/System Description
When the lumbar switches are pressed, they send 12-volt signal through the switch signal circuit to the memory seat module (MSM). The MSM interprets the signal and commands the lumbar 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 lumbar 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
| • | The current DTC will clear and set the code 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
Connector End View Reference
Description and Operation
Power Seats System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, observe the scan tool Memory Seat Module lumbar switch parameters while pressing and releasing the lumbar switch in both directions. The reading should change between Inactive and Active
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the lumbar switch.
- Ignition ON, verify the scan tool lumbar switch parameters listed below are Inactive.
- If all circuits test normal, test or replace the lumbar switch.
| • | Lumbar Forward Switch |
| • | Lumbar 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. |
| • | Lumbar forward switch terminal B |
| • | Lumbar rearward switch terminal E |
Component Testing
Lumbar Switch
- Ignition OFF, disconnect the harness connector at the lumbar switch.
- Test for infinite resistance between each lumbar direction signal terminal listed below and the B+ terminal D with the switch in the open position.
- Test for less than 1 ohm between each lumbar direction signal terminal listed below and the B+ terminal D with the switch in the closed position.
| • | Lumbar horizontal forward switch terminal B |
| • | Lumbar horizontal rearward switch terminal E |
| ⇒ | If not the specified value, replace the lumbar switch. |
| • | Lumbar horizontal forward switch terminal B |
| • | Lumbar horizontal rearward switch terminal E |
| ⇒ | If greater than the specified range, replace the lumbar switch. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for MSM replacement, setup, and programming |
