Pinpoint Test BW: Power-Stow Seat Motor and Sensor Functional Test - LH Third Row Power Seat
Seats
Pinpoint Tests
Pinpoint Test BW: Power-Stow Seat Motor and Sensor Functional Test - LH Third Row Power Seat
Refer to Wiring Diagram Set 120, Power Seats for schematic and connector information. Diagrams By Number
Normal Operation
The Power-Fold Seat Module (PFSM) supplies voltage and ground to the power-stow seat motor to move the seat to and from the STOW position when selected by the seat control switch. When STOW is selected from NORMAL or TAILGATE, the backrest will fold forward to release the spring loaded headrest. If an obstruction is detected in the STOW axis of movement the seat will stop, reverse movement a few inches and then stop again until the obstruction is removed. When the obstruction has been removed the seat control switch must be depressed again to reset the request. The seat will go to the power-stow seat motor home position (seat folded and latched to the floor) and then continue with the STOW request. If the PFSM detects an open or short in the power-stow seat motor circuitry, motor operation will be disabled. If a short to ground is present the motor will work in only one direction.
A Hall effect sensor is located inside each of the power-stow seat motor assemblies to detect power-stow seat motor movement and position to the PFSM. If the sensor does not detect motor movement during a request from the seat control switch, the PFSM will disable the power-stow seat motor output. When the seat control switch is pressed again the seat will move in short increments indicating a fault with the sensor or circuitry.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Power-stow seat motor and sensor
- PFSM
PINPOINT TEST BW: POWER-STOW SEAT MOTOR AND SENSOR FUNCTIONAL TEST - LH THIRD ROW POWER SEAT
NOTICE: The following pinpoint test uses a test light to simulate normal circuit loads. Use only the test light recommended in the Special Tools table at the beginning. To avoid connector terminal damage, use the Flex Probe Kit for the test light probe connection to the vehicle. Do not use the test light probe directly on any connector.
NOTE: Verify good battery condition before diagnosing the Power-Fold Seat Module (PFSM) system. Poor battery condition may interfere with PFSM operation. If battery voltage drops below 10 volts, seat movement will not start. If battery voltage drops below 8 volts, a started seat movement will stop.
NOTE: The accessory delay system (courtesy lamps) will time-out after 10 minutes and disable the third row power seat operation. Meter voltage measurements will be inaccurate when this occurs, which could lead to misdiagnosis. To enable the accessory delay system during diagnosis and testing, close and open any vehicle door.
-------------------------------------------------
BW1 CONFIRM THE SYSTEM FUNCTIONAL TEST HAS BEEN COMPLETED
- Verify the Functional Test - Third Row Power Seat has been completed before testing the power-stow seat motor and sensor.
- Has the Functional Test been completed?
Yes
GO to BW2.
No
CARRY OUT the Functional Test - Third Row Power Seat. GO to Pinpoint Test BT and return to this test only if directed to do so. Pinpoint Test BT: Functional Test - Third Row Power Seat
-------------------------------------------------
BW2 CHECK THE PFSM FOR OUTPUT VOLTAGE TO THE POWER-STOW SEAT MOTOR
- Access the PFSM. To access the PFSM, refer to the appropriate steps in Power-Fold Seat Module (PFSM) Service and Repair.
- NOTICE: Before moving the seat, make sure all parts are out from under it or damage can occur.
- Reposition the PFSM and wiring away from the seat so that the seat can be moved during testing without damaging the PFSM or wire harness.
- Detach the PFSM and wire harness completely from the LH load floor flapper panel.
- Lower the PFSM and wire harness to the floor in front of the seat.
- Before the seat is moved, make sure the wiring is clear from the pivot areas of the seat and will not be pinched or torn by seat movement.
- Verify the vehicle is in PARK and the liftgate is open.
- Verify the courtesy lights are on. If needed, close and open any door on the vehicle.
- Connect a test lamp between PFSM C4250C-12, circuit CPS03 (VT/GY) and PFSM C4250C-10, circuit CPS02 (GY/YE), by back-probing the connector.
- Press the STOW button and monitor the test lamp.
- Does the test lamp illuminate (may be momentary) when the STOW button is pressed?
Yes
GO to BW5.
No
GO to BW3.
-------------------------------------------------
BW3 CHECK THE LH POWER-STOW SEAT MOTOR AND CIRCUITS FOR A SHORT TO GROUND
- Disconnect: PFSM C4250C.
- Measure the resistance between:
- PFSM C4250C-12, circuit CPS03 (VT/GY), harness side and ground.
- PFSM C4250C-10, circuit CPS02 (GY/YE), harness side and ground.
- Are the resistances greater than 10,000 ohms?
Yes
GO to BW11.
No
GO to BW4.
-------------------------------------------------
BW4 CHECK THE LH POWER-STOW SEAT MOTOR AND CIRCUITS FOR A SHORT TO GROUND
- Disconnect: LH Power-Stow Seat Motor C4181.
- Remove the rear quarter trim finish panel to access the LH power-stow seat motor electrical connector.
- Measure the resistance between:
- PFSM C4250C-12, circuit CPS03 (VT/GY), harness side and ground.
- PFSM C4250C-10, circuit CPS02 (GY/YE), harness side and ground.
- Are the resistances greater than 10,000 ohms?
Yes
INSTALL a new power-stow seat motor. REFER to Power-Stow Seat Motor - Third Row Power-Stow Seat Motor - Third Row. TEST the system for normal operation.
No
REPAIR the circuit(s). TEST the system for normal operation.
-------------------------------------------------
BW5 CHECK THE LH POWER-STOW SEAT MOTOR AND CIRCUITS FOR AN OPEN
- Disconnect: PFSM C4250C.
- Measure the resistance between PFSM C4250C-12, circuit CPS03 (VT/GY), harness side and PFSM C4250C-10, circuit CPS02 (GY/YE), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to BW7.
No
GO to BW6.
-------------------------------------------------
BW6 CHECK THE POWER-STOW SEAT MOTOR CIRCUITS FOR AN OPEN
- Disconnect: LH Power-Stow Seat Motor C4181.
- Remove the rear quarter trim finish panel to access the LH power-stow seat motor electrical connector.
- Measure the resistance between:
- PFSM C4250C-12, circuit CPS03 (VT/GY), harness side and LH power-stow seat motor C4181-3, circuit CPS03 (VT/GY), harness side.
- PFSM C4250C-10, circuit CPS02 (GY/YE), harness side and LH power-stow seat motor C4181-1, circuit CPS02 (GY/YE), harness side.
- Are the resistances less than 5 ohms?
Yes
INSTALL a new power-stow seat motor. REFER to Power-Stow Seat Motor - Third Row Power-Stow Seat Motor - Third Row. TEST the system for normal operation.
No
REPAIR the circuit(s). TEST the system for normal operation.
-------------------------------------------------
BW7 CHECK THE PFSM FOR OUTPUT VOLTAGE TO THE STOW SENSOR
- Connect: PFSM C4250C.
- Verify the vehicle is in PARK and the liftgate is open.
- Verify the courtesy lights are on. If needed, close and open any door on the vehicle.
- Measure the voltage between PFSM C4250C-2, circuit LPS13 (BU/GY) and PFSM C4250C-5, circuit RPS13 (GN/OG), by back-probing the connector.
- Is the voltage greater than 5 volts?
Yes
GO to BW10.
No
GO to BW8.
-------------------------------------------------
BW8 CHECK THE LH POWER-STOW SEAT MOTOR SENSOR AND CIRCUIT FOR A SHORT TO GROUND
- Disconnect: PFSM C4250C.
- Measure the resistance between PFSM C4250C-2, circuit LPS13 (BU/GY), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to BW11.
No
GO to BW9.
-------------------------------------------------
BW9 CHECK THE LH POWER-STOW SEAT MOTOR SENSOR CIRCUIT FOR A SHORT TO GROUND
- Disconnect: LH Power-Stow Seat Motor C4181.
- Remove the rear quarter trim finish panel to access the LH power-stow seat motor electrical connector.
- Measure the resistance between PFSM C4250C-2, circuit LPS13 (BU/GY), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
INSTALL a new power-stow seat motor assembly. REFER to Power-Stow Seat Motor - Third Row Power-Stow Seat Motor - Third Row. TEST the system for normal operation.
No
REPAIR the circuit. TEST the system for normal operation.
-------------------------------------------------
BW10 CHECK THE LH POWER-STOW SEAT MOTOR SENSOR CIRCUITS FOR AN OPEN
- Disconnect: LH Power-Stow Seat Motor C4181.
- Remove the rear quarter trim finish panel to access the LH power-stow seat motor electrical connector.
- Disconnect: PFSM C4250C.
- Measure the resistance between:
- PFSM C4250C-2, circuit LPS13 (BU/GY), harness side and LH power-stow seat motor C4181-2, circuit LPS13 (BU/GY), harness side.
- PFSM C4250C-5, circuit RPS13 (GN/OG), harness side and LH power-stow seat motor C4181-4, circuit RPS13 (GN/OG), harness side.
- Are the resistances less than 5 ohms?
Yes
INSTALL a new power-stow seat motor assembly. REFER to Power-Stow Seat Motor - Third Row Power-Stow Seat Motor - Third Row. TEST the system for normal operation.
No
REPAIR the circuit(s). TEST the system for normal operation.
-------------------------------------------------
BW11 CHECK PFSM CONNECTORS AND PINS FOR DAMAGE AND RETEST THE SYSTEM
- Inspect the PFSM connectors for corrosion and pushed out or damaged pins and repair as necessary.
- Reconnect all the PFSM connectors.
- Operate the seats and determine if the concern is still present.
- Is the concern still present?
Yes
INSTALL a new PFSM. Refer to Power-Fold Seat Module (PFSM) Service and Repair. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
-------------------------------------------------