Pinpoint Test A: The Power Liftgate Is Inoperative - Does Not Open Or Close
- A1 RETRIEVE THE DTCs FROM THE LTM
- Use the recorded LTM DTCs from the continuous and LTM self-tests.
- Are any LTM DTCs recorded?
- Yes:
For DTC B106F, REFER to the LIFTGATE/TRUNK MODULE (LTM) DTC CHART .
For DTC B2908, GO to A5.
For DTC B2418, GO to A19.
For DTC B2419 or B2420, GO to A18.
For DTC B2935, GO to A10.
For DTC B2552, GO to A13.
For DTC B2936, B2819, B2937 or B2939, GO to A14.
For DTC B106E, GO to A16.
For DTC B1179, B117A or B117B, GO to A27.
- No: GO to A2 .
- A2 CHECK THE OPERATION OF THE POWER LIFTGATE SWITCHES
- Vehicle in PARK.
- Close the liftgate to the full CLOSED position (manually if necessary).
- Activate the power liftgate from the power liftgate control switch (instrument panel).
- Activate the power liftgate from the remote transmitter.
- Activate the power liftgate from the liftgate exterior handle.
- Does the power liftgate power open from any switch?
NOTE: Make sure the power liftgate is enabled (ON) in the vehicle message center.- Yes: GO to PINPOINT TEST B .
- No: GO to A3 .
- A3 CHECK CIRCUIT SBP14 (BN/RD) FOR AN OPEN
- Disconnect LTM C4174A.
- Measure the voltage between LTM C4174A-9, circuit SBP14 (BN/RD), harness side and ground.
- Is the voltage greater than 10 volts?
- Yes: GO to A4 .
- No:
VERIFY Smart Junction Box (SJB) fuse 14 (10A) is OK. If OK, REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM
self-test.
If not OK, REFER to the SYSTEM WIRING DIAGRAMS for Edge or SYSTEM WIRING DIAGRAMS for MKX to identify the possible causes of the circuit short. CLEAR the DTCs. REPEAT the LTM self-test.
- A4 CHECK CIRCUIT GD149 (BK/GY) FOR AN OPEN
- Ignition OFF.
- Measure the resistance between LTM C4174A-1, circuit GD149 (BK/GY), harness side and ground.
- Is the resistance less than 5 ohms?
- Yes: RECONNECT power liftgate system electrical connectors and GO to A5 .
- No: REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
- A5 CHECK THE DETENT AND FORKBOLT SWITCH PID
- Enter the following diagnostic mode on the scan tool: DataLogger - LTM .
- Operate the liftgate manually while monitoring the following LTM
PIDs:
- Detent Switch Status (DETENTSW)
- Forkbolt Switch Status (FORKBLT_S)
- Forkbolt Secondary Switch (FKSWSEC)
- Begin with the liftgate in the OPEN position, then slowly close the liftgate into each of the latch positions specified by the table below.LIFTGATE LATCH POSITION REFERENCE CHART
Liftgate Latch Position DETENTSW FKSWSEC FORKBLT_S Fully Unlatched Not active (1) Active Active In primary Active Not active Not active (1) If detent switch is active in the fully unlatched position, manually attempt to rotate the forkbolt towards the latched position. - Do the switch states agree with the table?
NOTE: The liftgate is in the primary position when in the full closed position. The liftgate is in the unlatch position when open and completely out of the striker. The liftgate can be placed in the unlatched position by lifting up on the liftgate handle.- Yes: GO to A10.
- No: GO to A6 .
- A6 CHECK THE OPERATION OF THE DETENT AND FORKBOLT SWITCHES
- Ignition OFF.
- Disconnect: LTM C4174B.
- Measure the resistance between LTM
C4174B, harness side and ground at each of the connector pins and each latch position specified by the table below.LIFTGATE LATCH POSITION REFERENCE CHART
Liftgate Latch Position C4174B Circuit Resistance Fully Unlatched Pin 3, circuit CPR66 (GY/YE) Greater than 10,000 ohms (1) Fully Unlatched Pin 5, circuit CPR64 (VT/OG) Less than 5 ohms Fully Unlatched Pin 4, circuit CPR65 (BU/GN) Less than 5 ohms Primary Pin 3, circuit CPR66 (GY/YE) Less than 5 ohms Primary Pin 5, circuit CPR64 (VT/OG) Greater than 10,000 ohms Primary Pin 4, circuit CPR65 (BU/GN) Greater than 10,000 ohms (1) If resistance measured is less than 5 ohms, manually rotate the forkbolt to the latched position and retest. - Do the resistance values agree with the table?
- Yes: GO to A31.
- No: GO to A7 .
- A7 CHECK THE DETENT AND FORKBOLT SWITCH GROUND CIRCUIT
- Disconnect: Liftgate Latch/Unlatch Assembly C4188.
- Measure the resistance between power liftgate latch/unlatch assembly C4188-8, circuit GD149 (BK/GY), harness side and ground.
- Is the resistance less than 5 ohms?
- Yes: GO to A8 .
- No: REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
- A8 CHECK THE DETENT AND FORKBOLT SWITCH CIRCUITS FOR AN OPEN
- Measure the resistance between power liftgate latch/unlatch assembly C4188, harness side and LTM
C4174B, harness side using the following table:POWER LIFTGATE LATCH/UNLATCH ASSEMBLY REFERENCE CHART
Power Liftgate Latch/Unlatch Assembly Circuit LTM C4188-2 CPR64 (VT/OG) C4174B-5 C4188-3 CPR65 (BU/GN) C4174B-4 C4188-5 CPR66 (GY/YE) C4174B-3 - Is the resistance less than 5 ohms on all circuits?
- Yes: GO to A9 .
- No: REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
- Measure the resistance between power liftgate latch/unlatch assembly C4188, harness side and LTM
C4174B, harness side using the following table:
- A9 CHECK THE DETENT AND FORKBOLT SWITCH CIRCUITS FOR A SHORT TO GROUND
- Measure the resistance between LTM C4174B-5, circuit CPR64 (VT/OG), harness side and ground; between LTM C4174B-4, circuit CPR65 (BU/GN), harness side and ground; then between LTM C4174B-3, circuit CPR66 (GY/YE), harness side and ground.
- Are the resistances greater than 10,000 ohms on all circuits?
- Yes:
CHECK the power liftgate latch connector for bent or corroded connections on the component side and harness side. REPAIR as necessary.
INSTALL a new power liftgate latch. REFER to HANDLES, LOCKS, LATCHES AND ENTRY SYSTEMS . CLEAR the DTCs. REPEAT the LTM self-test.
- No: REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
- A10 CHECK POWER LIFTGATE ROD OPERATION
- Check for correct function of power liftgate rod and cable.
- Correctly attached to motor and liftgate.
- Cable turns with actuator.
- Is the power liftgate rod operating correctly?
- Yes: GO to A11 .
- No: REPAIR as necessary. If installing a new power liftgate rod, REFER to POWER LIFTGATE ROD . CLEAR the DTCs. REPEAT the LTM self-test.
- Check for correct function of power liftgate rod and cable.
- A11 CHECK FOR VOLTAGE AT THE POWER LIFTGATE MOTOR AND CLUTCH
- Ignition ON.
- Liftgate in the fully CLOSED position.
- With the motor/clutch connected and while activating the power liftgate control switch, measure the voltage between power liftgate motor/clutch C4223-1, circuit CPR57 (GN/WH) backprobe and ground; then between power liftgate motor/clutch C4223-2, circuit CPR69 (BN/BU), backprobe and power liftgate motor/clutch C4223-7, circuit GD149 (BK/GY), backprobe.
- Are both of the voltages greater than 10 volts while activating the power liftgate switch?
- Yes: If no DTCs were present, GO to A18. If DTCs were present, INSTALL a new power liftgate motor. REFER to POWER LIFTGATE MOTOR . CLEAR the DTCs. REPEAT the LTM self-test.
- No: GO to A12 .
- A12 CHECK THE MOTOR AND CLUTCH VOLTAGE OUTPUTS AT THE LTM
- With the LTM connected, measure the voltage between LTM C4174A-6, circuit CPR58 (GN/OG), backprobe and ground; then between LTM C4174A-8, circuit CPR69 (BN/BU), backprobe and ground.
- Are the voltages greater than 10 volts while activating the power liftgate switch?
- Yes: GO to A14.
- No: GO to A13 .
- A13 CHECK FOR VOLTAGE AT THE LTM
- Ignition OFF.
- Disconnect: LTM C4174A.
- Measure the voltage between LTM C4174A-4 circuit SBB59 (BU/RD), harness side and ground.
- Is the voltage greater than 10 volts?
- Yes: If sent here because of DTC B2552, GO to A31. Otherwise, GO to A18.
- No:
VERIFY Battery Junction Box (BJB) fuse 59 (30A) is OK. If OK, REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM
self-test.
If not OK, REFER to the SYSTEM WIRING DIAGRAMS for Edge or SYSTEM WIRING DIAGRAMS for MKX to identify the possible causes of the circuit short. CLEAR the DTCs. REPEAT the LTM self-test.
- A14 CHECK CIRCUIT CLUTCH GROUND CIRCUIT GD149 (BK/GY) FOR AN OPEN
- Ignition OFF.
- Disconnect: LTM Module C4174A.
- Disconnect: Power Liftgate Motor C4223.
- Measure the resistance between power liftgate motor C4223-7, circuit GD149 (BK/GY), harness side and ground.
- Is the resistance less than 5 ohms?
- Yes: GO to A15 .
- No: REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
- A15 CHECK THE MOTOR/CLUTCH CIRCUITS FOR AN OPEN
- Measure the resistance between LTM
C4174A, harness side and the power liftgate motor/clutch C4223, harness side, using the following chart:POWER LIFTGATE MOTOR/CLUTCH REFERENCE CHART
LTM Circuit Power Liftgate Motor/Clutch C4174A-5 CPR57 (GN/WH) C4223-1 C4174A-6 CPR58 (GN/OG) C4223-5 C4174A-8 CPR69 (BN/BU) C4223-2 - Are the resistances less than 5 ohms?
- Yes: GO to A16 .
- No: REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
- Measure the resistance between LTM
C4174A, harness side and the power liftgate motor/clutch C4223, harness side, using the following chart:
- A16 CHECK THE MOTOR/CLUTCH CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: LTM C4174A.
- Disconnect: Power Liftgate Motor C4223.
- Measure the resistance between LTM C4174A-5, circuit CPR57 (GN/WH), harness side and ground; between LTM C4174A-6, circuit CPR58 (GN/OG), harness side and ground; then between LTM C4174A-8, circuit CPR69 (BN/BU), harness side and ground.
- Are the resistances greater than 10,000 ohms?
- Yes: GO to A17 .
- No: REPAIR the circuit. If DTC B106E was present, CLEAR the DTCs. REPEAT the LTM self-test.
- A17 CHECK THE MOTOR/CLUTCH CIRCUITS FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between LTM C4174A-5, circuit CPR57 (GN/WH), harness side and ground; between LTM C4174A-6, circuit CPR58 (GN/OG), harness side and ground; then between LTM C4174A-8, circuit CPR69 (BN/BU), harness side and ground.
- Is any voltage present?
- Yes: REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
- No: CHECK the power liftgate motor and clutch connectors for corrosion or pushed-out pins. REPAIR as necessary. CLEAR the DTCs. REPEAT the LTM self-test.
- A18 CHECK THE POSITION SENSOR PID
- Ignition OFF.
- Connect: All LTM Connectors.
- Connect: Power Liftgate Motor C4223.
- Ignition ON.
- Open the liftgate to the full OPEN position.
- Enter the following diagnostic mode on the scan tool: DataLogger - LTM .
- Monitor the LTM PIDs OPT_SEN_1 and OPT_SEN_2 while slowly closing the liftgate.
- Do both of the PID values alternate from ACTIVE to INACTIVE while the liftgate is moving?
- Yes: GO to A27.
- No: GO to A19 .
- A19 CHECK THE POSITION SENSOR POWER CIRCUIT
- Disconnect: Power Liftgate Motor C4223.
- Ignition ON.
- Measure the voltage between power liftgate motor C4223-4, circuit CPR55 (GN/BU), harness side and ground.
- Is the voltage approximately 4 to 5 volts?
- Yes: GO to A21.
- No: GO to A20 .
- A20 CHECK THE POSITION SENSOR POWER CIRCUIT FOR AN OPEN OR SHORT TO GROUND
- Ignition OFF.
- Disconnect: LTM C4174B.
- Measure the resistance between LTM C4174B-6, circuit CPR55 (GN/BU), harness side and power liftgate motor C4223-4, circuit CPR55 (GN/BU), harness side; and between LTM C4174B-6, circuit CPR55 (GN/BU), harness side and ground.
- Is the resistance less than 5 ohms between LTM and power liftgate motor; and greater than 10,000 ohms between LTM and ground?
- Yes: GO to A31.
- No: REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
- A21 CHECK THE POSITION SENSOR RETURN CIRCUIT
- Ignition OFF.
- Disconnect: Power Liftgate Motor C4223.
- Ignition ON.
- Measure the resistance between power liftgate motor C4223-9, circuit RPR55 (WH/BU), harness side and ground.
- Is the resistance less than 50 ohms?
- Yes: GO to A23.
- No: GO to A22 .
- A22 CHECK THE POSITION SENSOR RETURN CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: LTM C4174B.
- Measure the resistance between LTM C4174B-7, circuit RPR55 (WH/BU), harness side and power liftgate motor C4223-9, circuit RPR55 (WH/BU), harness side.
- Is the resistance less than 5 ohms?
- Yes: GO to A31.
- No: REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
- A23 CHECK THE POSITION SENSOR CIRCUITS FOR AN OPEN
- Ignition ON.
- Measure the voltage between power liftgate motor C4223-3, circuit VPR53 (BU/WH), harness side and ground; and between power liftgate motor C4223-8, circuit VPR54 (BU/BN), harness side and ground.
- Is the voltage approximately 5 volts for both measurements?
- Yes: INSTALL a new power liftgate motor. REFER to POWER LIFTGATE MOTOR . CLEAR the DTCs. REPEAT the LTM self-test.
- No: GO to A24 .
- A24 CHECK THE POSITION SENSOR CIRCUITS FOR AN OPEN
- Ignition OFF.
- Disconnect: LTM C4174B.
- Measure the resistance between power liftgate motor C4223, harness side and LTM
C4174B, harness side using the following chart:POWER LIFTGATE MOTOR REFERENCE CHART
Power Liftgate Motor Circuit LTM C4223-3 VPR53 (BU/WH) C4174B-20 C4223-8 VPR54 (BU/BN) C4174B-21 - Are the resistances less than 5 ohms?
- Yes: GO to A25 .
- No: REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
- A25 CHECK THE POSITION SENSOR CIRCUITS FOR A SHORT TO GROUND
- Measure the resistance between power liftgate motor C4223-8, circuit VPR54 (BU/BN), harness side and ground; and between power liftgate motor C4223-3, circuit VPR53 (BU/WH), harness side and ground.
- Are the resistances greater than 10,000 ohms?
- Yes: GO to A26 .
- No: REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
- A26 CHECK THE POSITION SENSOR CIRCUITS FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between power liftgate motor C4223-8, circuit VPR54 (BU/BN), harness side and ground; and between power liftgate motor C4223-3, circuit VPR53 (BU/WH), harness side and ground.
- Is any voltage present?
- Yes: REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
- No: GO to A31.
- A27 CHECK THE UNLATCH/CINCHING MOTOR CIRCUITS
- Ignition OFF.
- Disconnect: LTM C4174A.
- Close the power liftgate.
- Connect a fused jumper wire between LTM C4174A-3, circuit CPR62 (WH/BU), harness side and the positive side of the battery; and connect a jumper between LTM C4174A-2, circuit CPR61 (BN), harness side and ground.
- Does the unlatch/cinching motor activate when power and ground are applied?
NOTE: Do not apply power and ground to the unlatch actuator circuits for more than a few seconds or damage to the motor may occur.- Yes: GO to A31.
- No: GO to A28 .
- A28 CHECK THE UNLATCH/CINCHING MOTOR CIRCUITS FOR AN OPEN
- Disconnect: Liftgate Latch/Unlatch Assembly C4188.
- Measure the resistance between power liftgate latch C4188, harness side and LTM
C4174A, harness side, using the following chart:LIFTGATE LATCH/UNLATCH ASSEMBLY REFERENCE CHART
Liftgate Latch/Unlatch Assembly Circuit LTM C4188-1 CPR61 (BN) C4174A-2 C4188-4 CPR62 (WH/BU) C4174A-3 - Are the resistances less than 5 ohms?
- Yes: GO to A29 .
- No: REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
- A29 CHECK THE UNLATCH/CINCHING MOTOR CIRCUITS FOR A SHORT TO GROUND
- Measure the resistance between power liftgate latch C4188-1, circuit CPR61 (BN), harness side and ground; then between power liftgate latch C4188-4, circuit CPR62 (WH/BU), harness side and ground.
- Are the resistances greater than 10,000 ohms?
- Yes: GO to A30 .
- No: REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
- A30 CHECK THE UNLATCH ACTUATOR CIRCUITS FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between power liftgate latch C4188-1, circuit CPR61 (BN), harness side and ground; then between power liftgate latch C4188-4, circuit CPR62 (WH/BU), harness side and ground.
- Is voltage present on either circuit?
- Yes: REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
- No:
CHECK the power liftgate latch connectors for bent or corroded connections on the component side and harness side. REPAIR as necessary.
INSTALL a new power liftgate latch. REFER to HANDLES, LOCKS, LATCHES AND ENTRY SYSTEMS . CLEAR the DTCs. REPEAT the LTM self-test.
- A31 CHECK FOR CORRECT LTM OPERATION
- Disconnect all the LTM connectors.
- Check for:
- corrosion.
- pushed-out pins.
- Connect all the LTM connectors and make sure they are seated correctly.
- Make sure the liftgate is fully CLOSED.
- Operate the system and verify the concern is still present.
- Is the concern still present?
- Yes: INSTALL a new LTM . REFER to LIFTGATE/TRUNK MODULE (LTM) . REPEAT the LTM self-test.
- No: The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the LTM self-test.