Memory Seat Module (MSMD)

B210B-85-SYSTEM VOLTAGE LOW-SIGNAL ABOVE ALLOWABLE RANGE





For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Memory System is made up of the Memory Seat Module (MSM), Memory Switch, Driver Seat Switch, multiple Seat Motors which also each contain a hall-effect position sensor, and the Tilt and Telescope Steering Motors, both of which contain a hall-effect position sensor.

When the Driver Seat Switch is used to command seat movement, a signal is sent from the Switch to the MSM via a mux signal circuit. The MSM will then command the appropriate Seat Motor or Motors to move the seat in the commanded direction as long as the Driver Seat Switch is held in that direction. When seat movement is commanded, the MSM also powers the hall-effect position sensor located in each Seat Motor. These hall-effect sensors provide feedback to the MSM in relation to the seat's position. The Tilt and Telescoping Steering operate in a similar manner, with the Tilt Switch and Telescope Switch sending a signal to the MSM via a mux signal circuit. The Tilt Motor and Telescope Motor are then commanded by the MSM based on the Switch input. The Tilt Motor and Telescope Motor also each have a hall-effect position sensor.

The Memory Switch is used to set and recall memory seat and steering positions. When a Memory Switch button is pressed, a signal is sent from the Switch to the Driver Door Module (DDM) via a mux signal circuit. The DDM will then request the MSM perform the function via the Controller Area Network (CAN) bus circuit. If the SET button on the Memory Switch is pressed, followed by the 1 or 2 button, the MSM will store the seat and steering position based on the position inputs received from the hall-effect position sensor. If the 1 or 2 button on the Memory Switch is pressed, the MSM will recall the stored position for that particular selection and return the seat and steering column to the stored position. Memory position may also be recalled using a linked FOBIK transmitter. For driver safety, the MSM will prevent the memory recall function from being initiated if the transmission gear selector lever is not in the Park position or if the vehicle is moving. For further information Memory Seat Module - Operation.

- When Monitored:
Engine running, during seat motor operation.

- Set Condition:
The Memory Seat Module receives a high charging system voltage message over the CAN B Bus or detects voltage over 16.5 volts on the (A210) Fused B(+) circuit.





1. CHECK PCM FOR CHARGING SYSTEM DTC
1. With the scan tool, read the PCM DTCs.

Are there any Charging System DTCs set in the PCM?

Yes

- Perform the Charging System diagnostic procedures. Testing and Inspection.

No

- Go To 2

2. VERIFY THE DTC IS ACTIVE
1. With the scan tool, record and erase DTCs.
2. Turn the ignition off.
3. Start the engine and operate the driver power seat.
4. With the scan tool, read the active DTCs.

Does the scan tool display DTC B210B-85-SYSTEM VOLTAGE LOW-SIGNAL ABOVE ALLOWABLE RANGE?

Yes

- Replace the Memory Seat Module. Memory Seat Module - Removal.
- Perform the POWER SEAT SYSTEM VERIFICATION TEST. Power Seat System Verification Test.

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
- Perform the POWER SEAT SYSTEM VERIFICATION TEST. Power Seat System Verification Test.