Pinpoint Test E: The Power Liftgate Chime Is Inoperative
Power Liftgate
Pinpoint Tests
Pinpoint Test E: The Power Liftgate Chime is Inoperative
Refer to Wiring Diagram Set 109, Power Liftgate/Retractable Running Board for schematic and connector information. Diagrams By Number
Normal Operation
The power liftgate chime is controlled by the Liftgate/Trunk Module (LTM). To activate the chime, the LTM supplies a high-frequency voltage output on circuit CPR56 (VT/BN) and ground on circuit RPR56 (GY/VT).
- DTC B236A (Chime Output Circuit Open) - This DTC will set when the LTM detects an open in the chime output circuit.
- DTC B2903 (Chime Output Circuit Short to Battery) - This DTC will set when the LTM detects a short to voltage in the chime output circuit.
- DTC B2940 (Chime Output Circuit Short to Ground) - This DTC will set when the LTM detects a short to ground in the chime output circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Power liftgate motor
PINPOINT TEST E: THE POWER LIFTGATE CHIME IS INOPERATIVE
NOTICE: 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.
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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.
- Is AC voltage present?
Yes
INSTALL a new power liftgate motor. CLEAR the DTCs. REPEAT the LTM self-test.
No
GO to E2.
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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:
- Are the resistances less than 5 ohms?
Yes
GO to E3.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
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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.
- Are the resistances greater than 10,000 ohms?
Yes
GO to E4.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
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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.
- Is any voltage present?
Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
No
GO to E5.
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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) Service and Repair. 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.
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