Diagnostic Routine H

Diagnostic Routine H

Diagnostic Overview

The Power Seat is Inoperative, Does Not Operate Correctly - Both Rear

Refer to Wiring Diagram Set 120 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

REFER to Seating - Power-Fold .

DTC Fault Trigger Conditions






Pinpoint Test

NOTICE: Do not carry out this pinpoint test unless directed to do so from the Symptom Chart: Seating - Power-Fold Preliminary Inspection.

1. CONFIRM THE PRELIMINARY INSPECTION HAS BEEN COMPLETED

1. Perform the steps outlined in the Preliminary Inspection. REFER to Symptom Chart(s) Seating - 3rd Row.

Does either seat move to any position?








2. CHECK THE OPERATION OF EACH SEAT SEPARATELY

1. Check the seats.

2. Select LH (Left Hand) using the seat select button and operate the seat to each position (NORMAL, STOW and FOLD), allowing the seat to complete each selection.

3. Select RH (Right Hand) using the seat select button and operate the seat to each position, allowing the seat to complete each selection.

Do both seats operate correctly?








3. CHECK THE BCM (Body Control Module) FOR DTCs (Diagnostic Trouble Codes)

1. Ignition ON.

2. Using a scan tool, perform BCM (Body Control Module) self-test.

Are DTCs (Diagnostic Trouble Codes) present?








4. CHECK FOR VOLTAGE AND GROUND TO THE PFSM (Power-Fold Seat Module)

1. Disconnect: PFSM (Power-Fold Seat Module) C4250A.

- To access the PFSM (Power-Fold Seat Module), REFER to Power-Fold Seat Module (PFSM) .

2. Verify the vehicle is in PARK and the liftgate is open.

3. Verify the courtesy lights are on. If needed, close and open any door on the vehicle.

4. Measure:





Is the voltage greater than 11 volts?








5. CHECK THE PFSM (Power-Fold Seat Module) FOR VOLTAGE

1. Verify the vehicle is in PARK and the liftgate is open.

2. Verify the courtesy lights are on. If needed, close and open any door on the vehicle.

3. Measure:





Is the voltage greater than 11 volts?








6. CHECK THE THIRD ROW POWER SEAT RELAY FOR VOLTAGE AND GROUND

1. Disconnect: Third Row Power Seat Relay.

2. Verify the vehicle is in PARK and the liftgate is open.

3. Verify the courtesy lights are on. If needed, close and open any door on the vehicle.

4. Measure:





Is the voltage greater than 11 volts?








7. CHECK THE THIRD ROW POWER SEAT RELAY FOR VOLTAGE

1. Verify the vehicle is in PARK and the liftgate is open.

2. Verify the courtesy lights are on. If needed, close and open any door on the vehicle.

3. Measure:





Is the voltage greater than 11 volts?








8. CHECK THE THIRD ROW POWER SEAT RELAY FOR VOLTAGE

1. Measure:





Is the voltage greater than 11 volts?








9. CHECK THE CIRCUIT BETWEEN THE PFSM (Power-Fold Seat Module) AND THE THIRD ROW POWER SEAT RELAY FOR AN OPEN

1. Ignition OFF.

2. Measure:





Is the resistance less than 3 ohms?








10. CHECK THE PFSM (Power-Fold Seat Module) ENABLE CIRCUIT FOR A SHORT TO VOLTAGE

1. Disconnect: PFSM (Power-Fold Seat Module) C4250E.

- To access the PFSM (Power-Fold Seat Module), REFER to Power-Fold Seat Module (PFSM) .

2. Disconnect: BCM (Body Control Module) C2280C.

3. Ignition ON.

4. Measure:





Is any voltage present?








11. CHECK THE PFSM (Power-Fold Seat Module) ENABLE CIRCUIT FOR AN OPEN

1. Ignition OFF.

2. Disconnect: PFSM (Power-Fold Seat Module) C4250E.

- To access the PFSM (Power-Fold Seat Module), REFER to Power-Fold Seat Module (PFSM) .

3. Disconnect: BCM (Body Control Module) C2280C.

4. Measure:





Is the resistance less than 3 ohms?








12. CHECK THE PFSM (Power-Fold Seat Module) ENABLE CIRCUIT FOR A SHORT TO GROUND

1. Ignition OFF.

2. Disconnect: PFSM (Power-Fold Seat Module) C4250E.

- To access the PFSM (Power-Fold Seat Module), REFER to Power-Fold Seat Module (PFSM) .

3. Disconnect: BCM (Body Control Module) C2280C.

4. Measure:





Is the resistance greater than 10,000 ohms?








13. CHECK THE PFSM (Power-Fold Seat Module) ENABLE CIRCUIT FOR VOLTAGE

1. Disconnect: PFSM (Power-Fold Seat Module) C4250E.

- To access the PFSM (Power-Fold Seat Module), REFER to Power-Fold Seat Module (PFSM) .

2. Verify the vehicle is in PARK and the liftgate is open.

3. Verify the courtesy lights are on. If needed, close and open any door on the vehicle.

4. Measure:





Is the voltage greater than 11 volts?








14. CHECK FOR VOLTAGE TO THE SEAT CONTROL SWITCH
NOTICE: This pinpoint test step directs testing circuits using a back-probe method. Use the special back-probe tool specified in the tool list. Do not force test leads or other probes into connectors. Adequate care must be exercised to avoid connector terminal damage while making sure that good electrical contact is made with the circuit or terminal. Failure to follow these instructions may cause damage to wiring, terminals, or connectors and subsequent electrical faults.

1. Connect: PFSM (Power-Fold Seat Module) C4250A (if previously disconnected).

2. Remove the third row seat control switch, but do not disconnect the electrical connector at this time. REFER to Seat Control Switch .

3. Verify the vehicle is in PARK and the liftgate is open.

4. Verify the courtesy lights are on. If needed, close and open any door on the vehicle.

5. With all of the switch buttons at rest and seat select set to BOTH, measure:





Do the voltages agree with the expected voltages in the table?








15. CHECK CIRCUITS FOR VOLTAGE WITH THE SEAT CONTROL SWITCH DISCONNECTED

1. Disconnect: Third Row Seat Control Switch.

2. Verify the vehicle is in PARK and the liftgate is open.

3. Verify the courtesy lights are on. If needed, close and open any door on the vehicle.

4. Measure:





Do the voltages agree with the expected voltages in the table?








16. CHECK THE SEAT CONTROL SWITCH CIRCUITS FOR A SHORT TO VOLTAGE

1. Disconnect: PFSM (Power-Fold Seat Module) C4250C.

2. Disconnect: PFSM (Power-Fold Seat Module) C4250D.

3. Measure:





Is any voltage present?








17. CHECK THE SEAT CONTROL SWITCH CIRCUITS FOR AN OPEN OR SHORT TO GROUND

1. Measure:













Are the resistances less than 3 ohms between the seat control switch and the PFSM (Power-Fold Seat Module); and greater than 10,000 ohms between the seat control switch and ground?








18. CHECK THE SEAT CONTROL SWITCH CIRCUITS FOR A SHORT TOGETHER

1. Measure:





Are the resistances greater than 10,000 ohms?








19. CHECK THE VOLTAGE AT THE SEAT CONTROL SWITCH CIRCUITS
NOTICE: This pinpoint test step directs testing circuits using a back-probe method. Use the special back-probe tool specified in the tool list. Do not force test leads or other probes into connectors. Adequate care must be exercised to avoid connector terminal damage while making sure that good electrical contact is made with the circuit or terminal. Failure to follow these instructions may cause damage to wiring, terminals, or connectors and subsequent electrical faults.

1. NOTE: C4250E must be disconnected or inaccurate meter measurements may be taken.
Disconnect: PFSM (Power-Fold Seat Module) C4250E.

- To access the PFSM (Power-Fold Seat Module), REFER to Power-Fold Seat Module (PFSM) .

2. Verify the vehicle is in PARK and the liftgate is open.

3. Verify the courtesy lights are on. If needed, close and open any door on the vehicle.

4. Measure:





Do the measured voltages agree with the table?








20. CHECK THE LATCH SWITCH AND LATCH MOTOR RETURN CIRCUITS FOR AN OPEN

1. Disconnect: Left Seat Latch Switch.

- Gain access to the LH (Left Hand) latch switch connector. REFER to Seat Control Switch .

2. Disconnect: Left Seat Latch Motor.

3. Disconnect: PFSM (Power-Fold Seat Module) C4250A.

4. Measure:









Are the resistances less than 3 ohms?








21. CHECK BCM (Body Control Module) CONNECTORS AND PINS FOR DAMAGE AND RETEST THE SYSTEM

1. Disconnect and inspect all BCM (Body Control Module) connectors.

2. Repair:

- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins as necessary
- pushed-out pins - install new pins as necessary

3. Reconnect all previously disconnected electrical connectors.

4. Operate the seats and determine if the concern is still present.

Is the concern still present?








22. CHECK PFSM (Power-Fold Seat Module) CONNECTORS AND PINS FOR DAMAGE AND RETEST THE SYSTEM

1. Disconnect and inspect all PFSM (Power-Fold Seat Module) connectors.

2. Repair:

- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins as necessary
- pushed-out pins - install new pins as necessary

3. Reconnect all previously disconnected electrical connectors.

4. Operate the seats and determine if the concern is still present.

Is the concern still present?