B1830
DTC B1830, B1835, B1840, or B1845
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 B1830
- Driver Seat Lumbar Forward Switch Circuit
DTC B1835
- Driver Seat Lumbar Rearward Switch Circuit
Diagnostic Fault Information
Circuit/System Description
The power lumbar switches are inputs to the memory seat module (MSM). The seat module supplies the switch assembly with a battery positive switch supply circuit and monitor the switch signal circuits. In an inactive state the switch signal circuits are floating and when a switch is pressed the signal circuit is closed to the switch power circuit within the lumbar switch assembly. When battery voltage is present on the switch signal circuit the seat module determines the switch status to be active.
Conditions for Running the DTC
The battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
A switch signal circuit to the MSM is active for more than 60 seconds.
Action Taken When the DTC Sets
The MSM will disable the power lumbar function.
Conditions for Clearing the DTC
* The DTC will be stored as a history code when the fault is no longer present.
* The history DTC will clear after 100 consecutive fault-free ignition cycles have occurred.
Diagnostic Aids
The scan tool may reference the Memory Seat Module as the Driver Seat Module.
Reference Information
Schematic Reference
Driver Seat Schematics (Driver Seat Schematics)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Memory Seats Description and Operation (Memory Seats Description and Operation)
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 Driver Seat Module lumbar switch parameter while operating the lumbar switch in both directions. The reading should change between Idle, Forward, and Rearward.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the lumbar adjuster switch.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal E and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
3. Verify the scan tool Lumbar Switches parameter is Idle.
• 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 terminal A
* Lumbar rearward terminal D
4. Install a 3A fused jumper wire between the appropriate signal circuit listed below and the B+ circuit terminal E. Verify the scan tool Lumbar Switches parameter is Forward or Rearward.
* Lumbar forward terminal A
* Lumbar rearward terminal D
• If not the specified value, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.
5. If all circuits test normal, test or replace the lumbar adjuster switch.
Component Testing
Seat Adjuster Switch Test
1. Ignition OFF, disconnect the harness connector at the lumbar adjuster switch.
2. Test for infinite resistance between each seat direction signal terminal listed below and the B+ terminal E with the switch in the open position.
* Lumbar forward switch terminal A
* Lumbar rearward switch terminal D
• If not the specified value, replace the lumbar adjuster switch.
3. Test for less than 1 ohm between each seat direction signal terminal listed below and the B+ terminal E with the switch in the closed position.
* Lumbar forward switch terminal A
* Lumbar rearward switch terminal D
• If greater than the specified range, replace the lumbar 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, programming, and setup