Circuit Description
Battery positive voltage is supplied to the rear seat module (RSM) from a 30-amp fuse located in the rear fuse block. When commanded, this voltage is used by the RSM to power the seat motors through there respective motor control circuits. During seat operations, the driven motor current is monitored through the motor control circuits by the RSM. When an overcurrent condition is detected, the RSM disables the seat motors in order to protect the internal RSM circuitry.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC B1547 Seat Back Rotation Motor Circuit |
| • | DTC B1770 Seat Motor 2 (Assembly Horizontally) Circuit |
| • | DTC B1785 Seat Motor (Recline) Circuit |
Conditions for Running the DTC
The RSM monitors for overcurrent only when the seat motors are active.
Conditions for Setting the DTC
The RSM will set this DTC when the measured current exceeds 81 amps for 100 milliseconds.
Action Taken When the DTC Sets
| • | If the seat is moving when this condition occurs, the operation will be aborted. |
| • | The RSM will not respond to all third row seat switch inputs. |
| • | The RSM will set a history DTC. |
Conditions for Clearing the DTC
| • | The RSM does not detect an overcurrent condition during seat movement. |
| • | The history code will clear if the RSM does not detect an overcurrent for 100 ignition cycles. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This test determines which directional motor exhibits excessive current.
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This test determines if the suspect motor has an internal short to ground.
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This test verifies the repair.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Rear Seat 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 |
Did the rear seat module (RSM) set a history overcurrent DTC for any of the seat motors? | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | |
Did the RSM set a history overcurrent DTC for the seat motor? | Go to Step 4 | Go to Step 5 | |
4 | Test the motor control circuits of the suspect motor for a short to ground. Refer to Circuit Testing and 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 harness connector of the suspect seat motor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector 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 RSM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 8 |
7 | Replace the suspect seat motor. Refer to Rear Seat Number 2 Back Pivot Actuator Motor Replacement - Cushion , Rear Seat Number 2 Back Pivot Actuator Motor Replacement - Back Cushion , or Rear Seat Number 2 Back Recliner Actuator Motor Replacement . Did you complete the replacement? | Go to Step 9 | -- |
8 | Replace the RSM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | Go to Step 9 | -- |
Does the DTC reset? | Go to Step 2 | System OK | |
