Pinpoint Test E: The Power Liftgate Chime Is Inoperative

NOTE: Use the correct probe adapter(s) from the Flex Probe Kit when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

E1 CHECK FOR VOLTAGE TO THE POWER LIFTGATE CHIME
- Ignition ON.
- Set the parking brake to the ON position.
- Open the liftgate.
- NOTE: The LTM applies voltage to the power liftgate chime for one second after the rear power liftgate switch is pressed, when the transmission is not in the PARK position and the liftgate is in the open position.
- With the power liftgate chime still connected, press the rear power liftgate switch and measure the voltage between power liftgate chime C4186-1, circuit CPR56 (VT/BN), back probe and power liftgate chime C4186-2, circuit RPR56 (GY/VT), back probe.
  
  Fig 1: Measuring Voltage Between Power Liftgate Chime C4186-1 And C4186-2
  Courtesy of FORD MOTOR CO.
- Is AC voltage present?
- Yes : INSTALL a new power liftgate motor. CLEAR the DTCs. REPEAT the LTM self-test.
- No : GO to E2.

E2 CHECK THE POWER LIFTGATE CHIME CIRCUITS FOR AN OPEN

Ignition OFF.
Disconnect: Power Liftgate Chime C4186.
Disconnect: LTM C4174A.

Measure the resistance between LTM C4174A, harness side and power liftgate chime C4186, harness side using the following chart:

POWER LIFTGATE CHIME REFERENCE

LTM	Circuit	Power Liftgate Chime
C4174A-9	CPR56 (VT/BN)	C4186-1
C4174A-22	RPR56 (GY/VT)	C4186-2

Fig 2: Measuring Resistance Between LTM C4174A And Power Liftgate Chime C4186

Courtesy of FORD MOTOR CO.

Are the resistances less than 5 ohms?

Yes : GO to E3.
No : REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.

E3 CHECK THE POWER LIFTGATE CHIME CIRCUITS FOR A SHORT TO GROUND
- Measure the resistance between power liftgate chime C4186-1, circuit CPR56 (VT/BN), harness side and ground; then between power liftgate chime C4186-2, circuit RPR56 (GY/VT), harness side and ground.
  
  Fig 3: Measuring Resistance Between Power Liftgate Chime C4186-1 And Ground
  Courtesy of FORD MOTOR CO.
- Are the resistances greater than 10,000 ohms?
- Yes : GO to E4.
- No : REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
E4 CHECK THE POWER LIFTGATE CHIME CIRCUITS FOR A SHORT TO VOLTAGE
- Measure the voltage between power liftgate chime C4186-1, circuit CPR56 (VT/BN), harness side and ground; then between power liftgate chime C4186-2, circuit RPR56 (GY/VT), harness side and ground.
  
  Fig 4: Measuring Voltage Between Power Liftgate Chime C4186-1 And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage present?
- Yes : REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
- No : GO to E5.
E5 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.