• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Switch Supply Voltage | 1 | 1 | -- | -- |
Lumbar Forward Switch Signal | 1 | 1 | B1830, B1835 | -- |
Lumbar Rearward Switch Signal | 1 | 1 | B1830, B1835 | -- |
Switch Ground | -- | 2 | -- | |
1. Lumbar switches inoperative 2. No effect |
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.
The battery voltage must be between 9-16 volts.
A switch signal circuit to the MSM is active for more than 60 seconds.
The MSM will disable the power lumbar function.
• | 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. |
The scan tool may reference the Memory Seat Module as the Driver Seat Module.
Memory Seats Description and Operation
Control Module References for scan tool information
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.
⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. |
⇒ | 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 |
• | 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. |
• | Lumbar forward switch terminal A |
• | Lumbar rearward switch terminal D |
⇒ | If not the specified value, replace the lumbar adjuster switch. |
• | Lumbar forward switch terminal A |
• | Lumbar rearward switch terminal D |
⇒ | If greater than the specified range, replace the lumbar adjuster switch. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for MSM replacement, programming, and setup |