Circuit Description
The seat adjuster motors are controlled by the driver seat module (DSM) through the adjuster motor control circuits. In an inactive state both of the motor control circuits are grounded within the DSM. In an active state the DSM switches the appropriate motor control circuit to battery positive voltage. The direction of the adjuster motor rotation is determined by which of the motor control circuits is switched to battery positive voltage while the other remains grounded. During adjuster motor operation the DSM also monitors the current flow through the motor control circuits.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B3962 Seat Motors Over Current
Conditions for Running the DTC
The system voltage must be between 9-16 volts.
Conditions for Setting the DTC
A motor control circuit current monitored by the DSM is determined to be shorted to ground.
Action Taken When the DTC Sets
| • | The DSM will disable the affected adjuster motor. |
| • | When the fault is no longer present, a history DTC will be stored in the DSM and motor operation will be restored. |
Conditions for Clearing the DTC
| • | The DTC will be current for as long as the fault is present. |
| • | When the fault is no longer present the DTC will be a history status code. |
| • | The history DTC will be cleared after 100 error free ignition cycles, or by using the scan tool clearing DTCs feature. |
Diagnostic Aids
When an adjuster motor control circuit is shorted to ground the DSM will also set a DTC for the affected motor.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Driver Seat Schematics Connector End View Reference: Power Seat Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 | Attempt to operate all of the seat adjuster motors through the full range of adjustment. Do all of the seat adjuster motors operate normally? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
3 |
Does the test lamp illuminate when the switch is activated in both directions? | Go to Step 5 | Go to Step 4 |
4 | Test the motor control circuits for a short to ground. Refer to Circuit Testing and to Wiring Repairs. Did you find and correct the condition? | Go to Step 9 | Go to Step 6 |
5 | Inspect for poor connections at the adjuster motor connector. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs. Did you find and correct the condition? | Go to Step 9 | Go to Step 7 |
6 | Inspect for poor connections at the harness connector of the driver seat module (DSM). Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs. Did you find and correct the condition? | Go to Step 9 | Go to Step 8 |
7 | Replace the appropriate adjuster motor assembly. Refer to Front Seat Adjuster Motor Replacement . Did you complete the replacement? | Go to Step 9 | -- |
8 | Replace the DSM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 9 | -- |
9 |
Does the DTC reset? | Go to Step 2 | System OK |
