Pinpoint Test D: Power Liftgate Reverses During The Power Close Operation
Power Liftgate
Pinpoint Test D: The Power Liftgate Does Not Operate Correctly - Reverses During the Power Close Operation
Normal Operation
When the power liftgate moves in the close direction, the Liftgate/Trunk Module (LTM) monitors the pinch strips and motor position sensor for obstacle detection. If the LTM (Liftgate/Trunk Module) detects an obstacle, it reverses the power liftgate.
The LTM (Liftgate/Trunk Module) monitors the left and right pinch strips and if either pinch strip is pressed the LTM (Liftgate/Trunk Module) reverses the power liftgate.
The LTM (Liftgate/Trunk Module) monitors the position sensor feedback for position and movement. If the LTM (Liftgate/Trunk Module) is unable to determine the liftgate position or the movement indicates an obstacle the LTM (Liftgate/Trunk Module) reverses the power liftgate.
The LTM (Liftgate/Trunk Module) also monitors the power liftgate latch status once the liftgate closes to a secondary latch position. If the liftgate is unable to obtain a primary latch position the LTM (Liftgate/Trunk Module) aborts the power close.
- DTC B107D (Obstacle Detected While Closing)- an on-demand DTC that sets when the LTM (Liftgate/Trunk Module) detects an obstacle during a power open/close.
- DTC B2419 (Sensor 1 Invalid)- a continuous and on-demand DTC that sets when the LTM (Liftgate/Trunk Module) detects the position sensor feedback signals are not correct.
- DTC B2420 (Sensor 2 Invalid)- a continuous and on-demand DTC that sets when the LTM (Liftgate/Trunk Module) detects the position sensor feedback signals are not correct.
This pinpoint test is intended to diagnose the following:
- Mechanical binding
- Liftgate alignment
- Wiring, terminals or connectors
- Power liftgate latch
- Power liftgate motor
- LTM (Liftgate/Trunk Module)
PINPOINT TEST D : THE POWER LIFTGATE DOES NOT OPERATE CORRECTLY - REVERSES DURING THE POWER CLOSE OPERATION
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.
D1 CHECK THE MANUAL OPERATION OF THE LIFTGATE
- Turn the power liftgate off (disable) from the message center.
- While manually opening and closing the liftgate, check the liftgate for:
- liftgate/wedge alignment.
- strut operation (struts should push liftgate open when beyond half open).
- power liftgate latch (should latch completely).
Does the liftgate open and close correctly?
Yes
If the liftgate reverses near the midpoint of travel, GO to D2.
If the liftgate reverses near or at the latch, GO to D12.
No
REPAIR and ALIGN as necessary. REFER to Liftgate Alignment Adjustments. CLEAR the DTCs. REPEAT the Liftgate/Trunk Module (LTM) self-test.
D2 CHECK THE LIFTGATE POSITION SENSOR (OPT_SEN_1) AND (OPT_SEN_2) PIDs
- Ignition ON.
- Open the liftgate to the full open position.
- Enter the following diagnostic mode on the scan tool: LTM (Liftgate/Trunk Module) DataLogger.
- Monitor the LTM (Liftgate/Trunk Module) 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 D12.
No
GO to D3.
D3 CHECK FOR VOLTAGE TO THE POSITION SENSOR
- Ignition OFF.
- Disconnect: Power Liftgate Motor C4223.
- Ignition ON.
- Measure the voltage between the power liftgate motor C4223-2, circuit CPR55 (GN/BU), harness side and the power liftgate motor C4223-3, circuit RPR55 (WH/BU), harness side.
Is the voltage greater than 10 volts?
Yes
GO to D8.
No
GO to D4.
D4 CHECK THE POSITION SENSOR VOLTAGE CIRCUIT
- Measure the voltage between power liftgate motor C4223-2, circuit CPR55 (GN/BU), harness side and ground.
Is the voltage greater than 10 volts?
Yes
GO to D7.
No
GO to D5.
D5 CHECK THE POSITION SENSOR VOLTAGE CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: LTM (Liftgate/Trunk Module) C4174B.
- Ignition ON.
- Measure the voltage between power liftgate motor C4223-2, circuit CPR55 (GN/BU), harness side and ground.
Is any voltage present?
Yes
REPAIR circuit CPR55 (GN/BU) for a short to voltage. CLEAR the DTCs. REPEAT the LTM (Liftgate/Trunk Module) self-test.
No
GO to D6.
D6 CHECK THE POSITION SENSOR VOLTAGE CIRCUIT FOR AN OPEN OR SHORT TO GROUND
- Measure the resistance between LTM (Liftgate/Trunk Module) C4174B-6, circuit CPR55 (GN/BU), harness side and power liftgate motor C4223-2, circuit CPR55 (GN/BU), harness side; and between LTM (Liftgate/Trunk Module) C4174B-6, circuit CPR55 (GN/BU), harness side and ground.
Is the resistance less than 5 ohms between LTM (Liftgate/Trunk Module) and power liftgate motor; and greater than 10,000 ohms between
LTM (Liftgate/Trunk Module) and ground?
Yes
GO to D17.
No
REPAIR the circuit for an open or short to ground. CLEAR the DTCs. REPEAT the LTM (Liftgate/Trunk Module) self-test.
D7 CHECK THE POSITION SENSOR RETURN CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: LTM (Liftgate/Trunk Module) C4174B.
- Measure the resistance between the LTM (Liftgate/Trunk Module) C4174B-7, circuit RPR55 (WH/BU), harness side and the power liftgate motor C4223-3, circuit RPR55 (WH/BU), harness side.
Is the resistance less than 5 ohms?
Yes
GO to D17.
No
REPAIR the circuit for an open. CLEAR the DTCs. REPEAT the LTM (Liftgate/Trunk Module) self-test.
D8 CHECK THE POSITION SENSOR CIRCUITS FOR REFERENCE VOLTAGE
- Ignition ON.
- Measure the voltage between the power liftgate motor C4223-5, circuit VPR53 (BU/WH), harness side and ground; and between the power liftgate motor C4223-6, circuit VPR54 (BU/BN), harness side and ground.
Are the voltages approximately 5 volts?
Yes
INSTALL a new power liftgate motor. REFER to Power Liftgate Motor Service and Repair. CLEAR the DTCs. REPEAT the LTM (Liftgate/Trunk Module) self-test.
No
GO to D9.
D9 CHECK THE POSITION SENSOR CIRCUITS FOR AN OPEN
- Ignition OFF.
- Disconnect: LTM (Liftgate/Trunk Module) C4174B.
- Measure the resistance between the power liftgate motor C4223, harness side and the LTM (Liftgate/Trunk Module) C4174B, harness side using the following chart:
Power Liftgate Motor Connector-Pin Circuit LTM (Liftgate/Trunk Module) Connector-Pin C4223-5 VPR53 (BU/WH) C4174B-20 C4223-6 VPR54 (BU/BN) C4174B-21
Are the resistances less than 5 ohms?
Yes
GO to D10.
No
REPAIR the circuit in question for an open. CLEAR the DTCs. REPEAT the LTM (Liftgate/Trunk Module) self-test.
D10 CHECK THE POSITION SENSOR CIRCUITS FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between the power liftgate motor C4223-5, circuit VPR53 (BU/WH), harness side and ground; and between the power liftgate motor C4223-6, circuit VPR54 (BU/BN), harness side and ground.
Is any voltage present?
Yes
REPAIR the circuit in question for a short to voltage. CLEAR the DTCs. REPEAT the LTM (Liftgate/Trunk Module) self-test.
No
GO to D11.
D11 CHECK THE POSITION SENSOR CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between the power liftgate motor C4223-5, circuit VPR53 (BU/WH), harness side and ground; and between the power liftgate motor C4223-6, circuit VPR54 (BU/BN), harness side and ground.
Are the resistances greater than 10,000 ohms?
Yes
GO to D17.
No
REPAIR the circuit in question for an open. CLEAR the DTCs. REPEAT the LTM (Liftgate/Trunk Module) self-test.
D12 CHECK THE DETENT AND FORKBOLT SWITCH PIDs
- Enter the following diagnostic mode on the scan tool: LTM (Liftgate/Trunk Module) DataLogger.
- Operate the liftgate manually while monitoring the following LTM (Liftgate/Trunk Module) PIDs:
- Detent Switch Status (DETENTSW)
- Forkbolt Switch Status (FORKBLT_S)
- Forkbolt Secondary Switch (FKSWSEC)
- NOTE: The liftgate is in the primary position when the liftgate is in the full closed position. The liftgate is in the unlatch position when the liftgate is open and completely out of the striker.
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 DETENTSW FORKBLT_S FKSWSEC Fully Unlatched Inactive aActive Active Primary Active Inactive Inactive
a 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?
Yes
GO to D17.
No
GO to D13.
D13 CHECK THE OPERATION OF THE DETENT AND FORKBOLT SWITCHES
- Ignition OFF.
- Disconnect: LTM (Liftgate/Trunk Module) C4174B.
- Measure the resistance between LTM (Liftgate/Trunk Module) C4174B, harness side and ground at each of the connector pins and each latch position specified by the table below.
Liftgate Latch Position LTM (Liftgate/Trunk Module) Connector-Pin Circuit Resistance Fully Unlatched C4174B-3 CPR66 (GY/YE) Greater than 10,000 ohms aFully Unlatched C4174B-5 CPR64 (VT/OG) Less than 5 ohms Fully Unlatched C4174B-4 CPR65 (BU/GN) Less than 5 ohms Primary C4174B-3 CPR66 (GY/YE) Less than 5 ohms Primary C4174B-5 CPR64 (VT/OG) Greater than 10,000 ohms Primary C4174B-4 CPR65 (BU/GN) Greater than 10,000 ohms
a 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 D17.
No
GO to D14.
D14 CHECK THE DETENT AND FORKBOLT SWITCH GROUND CIRCUIT
- Disconnect: Power Liftgate Latch C4339.
- Measure the resistance between power liftgate latch C4339-8, circuit GD149 (BK/GY), harness side and ground.
Is the resistance less than 5 ohms?
Yes
GO to D15.
No
REPAIR the circuit for an open. CLEAR the DTCs. REPEAT the LTM (Liftgate/Trunk Module) self-test.
D15 CHECK THE DETENT AND FORKBOLT SWITCH CIRCUITS FOR AN OPEN
- Measure the resistance between power liftgate latch C4339, harness side and LTM (Liftgate/Trunk Module) C4174B, harness side using the following table:
Power Liftgate Latch Connector-Pin Circuit LTM (Liftgate/Trunk Module) Connector-Pin C4339-2 CPR64 (VT/OG) C4174B-5 C4339-3 CPR65 (BU/GN) C4174B-4 C4339-5 CPR66 (GY/YE) C4174B-3
Is the resistance less than 5 ohms on all circuits?
Yes
GO to D16.
No
REPAIR the circuit in question for an open. CLEAR the DTCs. REPEAT the LTM (Liftgate/Trunk Module) self-test.
D16 CHECK THE DETENT AND FORKBOLT SWITCH CIRCUITS FOR A SHORT TO GROUND
- Measure the resistance between the LTM (Liftgate/Trunk Module) C4174B-5, circuit CPR64 (VT/OG), harness side and ground; then between the LTM (Liftgate/Trunk Module) C4174B-4, circuit CPR65 (BU/GN), harness side and ground; then between the LTM (Liftgate/Trunk Module) C4174B-3, circuit CPR66 (GY/YE), harness side and ground.
Is the resistance greater than 10,000 ohms on all circuits?
Yes
INSTALL a new power liftgate latch. CLEAR the DTCs. REPEAT the LTM (Liftgate/Trunk Module) self-test.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM (Liftgate/Trunk Module) self-test.
D17 CHECK FOR CORRECT LTM (Liftgate/Trunk Module) OPERATION
- Disconnect all the LTM (Liftgate/Trunk Module) connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the LTM (Liftgate/Trunk Module) 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 (Liftgate/Trunk Module). REFER to Liftgate/Trunk Module (LTM) Service and Repair. TEST the system for normal operation.
No
The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.