Refer to
Cell 141: Memory Seat Module, Transducers and Motors
.
The memory seat module (MSM) controls the seat rear height motor power and ground through CKT 282 (YEL) and CKT 283 (LT BLU). The MSM also senses the seat rear height motor position through the seat rear height transducer, utilizing CKT 569 (RED) for reference voltage and utilizing CKT 569 (BLK) as a sensor ground.
The DTC will set if the MSM detects that the rear height motor is not responding to the MSM commands due to the following conditions:
• | An open circuit |
• | A short to ground |
• | A short to power |
• | An inoperative motor |
• | A history DTC will clear after 100 consecutive fault free ignition cycles. |
• | Use a scan tool in order to clear history and current DTCs. |
One or more of the following conditions may be the cause of an intermittent failure:
• | A poor connection |
• | A break in the wire insulation that exposes the internal wire |
• | A wire broken inside the insulation |
The numbers below refer to the step numbers on the diagnostic table.
This step inspects for current DTCs.
This step inspects the wiring between the seat rear height motor and the MSM for open circuits.
This step repairs the open(s) in the wiring between the seat rear height motor and the MSM.
This step inspects the wiring between the seat rear height motor and the MSM for short(s) to ground.
This step repairs the short(s) to ground in the wiring between the seat rear height motor and the MSM.
This step verifies proper MSM operation.
This step replaces a defective seat rear height motor.
This step replaces a defective MSM.
Step | Action | Value(s) | Yes | No | ||||
---|---|---|---|---|---|---|---|---|
1 | Did you perform the Power Seat Systems Diagnostic System Check? | -- | Go to Step 2 | |||||
Does DTC B1780 reset? | -- | Go to Step 3 | ||||||
Is continuity present? | -- | Go to Step 5 | Go to Step 4 | |||||
Locate and repair the open circuit(s). Is the repair complete? | -- | -- | ||||||
Is continuity present? | -- | Go to Step 6 | Go to Step 7 | |||||
Locate and repair the short(s) to ground. Is the repair complete? | -- | -- | ||||||
Does the lamp light when the seat rear height switch is in the FORWARD and BACK positions? | -- | Go to Step 8 | Go to Step 9 | |||||
Replace the seat rear height motor. Is the repair complete? | -- | -- | ||||||
Replace the MSM. Is the repair complete? | -- | -- |