Circuit Description
The seat adjuster motors are controlled by the memory seat module (MSM) through the adjuster motor control circuits. The MSM also monitors current flow through the adjuster motor control circuits. In an inactive state the control circuits are closed to ground within the MSM. In an active state the appropriate adjuster motor control circuit is switched to battery voltage within the MSM. The direction of the adjuster motor rotation is determined by which of the control circuits is switched to battery voltage while the other remains grounded.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC B1770 Seat Assembly Horizontal Motor Circuit |
| • | DTC B1775 Seat Front Vertical Motor Circuit |
| • | DTC B1780 Seat Rear Vertical Motor Circuit |
| • | DTC B1785 Seat Recline Motor Circuit |
Conditions for Running the DTC
The system voltage must be between 9-16 volts.
Conditions for Setting the DTC
The adjuster motor control circuit current monitored by the MSM is high, low, or open.
Action Taken When the DTC Sets
| • | The MSM will disable the seat adjuster motor for which a current status DTC is set. |
| • | When the fault is no longer present a history status DTC will be stored, and adjuster 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. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step verifies that the DTC is current or history by attempting to operate the seat adjuster motor for which the code is set.
-
This step tests the adjuster motor control circuits for proper operation.
Step | Action | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Memory Seats Schematics Connector End View Reference: Power Seat Connector End Views | |||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | ||||||
Does the seat adjuster motor operate through the full range of adjustment? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 | |||||||
Does the test lamp turn ON and OFF with each command? | Go to Step 5 | Go to Step 4 | |||||||
4 | Test and repair the adjuster motor control circuits for the following conditions:
Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. 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 Circuit Testing and to Wiring Repairs in Wiring Systems. 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 memory seat module (MSM). Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 8 | ||||||
7 | Replace the seat adjuster motor assembly. Refer to Power Seat Adjuster Mechanism Replacement . Did you complete the replacement? | Go to Step 9 | -- | ||||||
8 | Replace the MSM. Refer to Control Module References in Computer/Integrating Systems 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 | ||||||
