Pinpoint Test G: The Power Liftgate Does Not Power Close (Power Open OK)
Power Liftgate
Pinpoint Tests
Pinpoint Test G: The Power Liftgate Does Not Power Close (Power Open OK)
Refer to Wiring Diagram Set 109, Power Liftgate/Retractable Running Board for schematic and connector information. Diagrams By Number
Normal Operation
When the power liftgate moves in the close direction, the Liftgate/Trunk Module (LTM) monitors the pinch strips and position sensor for obstacle detection. The LTM uses a 5-volt reference signal on circuit CPR52 (YE/VT) and a return signal on circuit RPR52 (VT/GY) for the left pinch strip. The LTM uses a 5-volt reference signal on circuit CPR51 (YE/OG) and a return signal on circuit RPR52 (VT/GY) for the right pinch strip. The right and left pinch strip return signal circuits are spliced together.
B2699-B2702:
NOTE: Initialize the power liftgate before proceeding with this pinpoint test. Refer to Power Liftgate Initialization Programming and Relearning.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Pinch strip
- Power liftgate latch
- LTM
PINPOINT TEST G: THE POWER LIFTGATE DOES NOT POWER CLOSE (POWER OPEN OK)
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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G1 RETRIEVE THE DTCs FROM THE LTM
- Use the recorded LTM DTCs from the continuous and LTM self-tests.
- Is DTC B2699, B2700, B2701 or B2702 present?
Yes
GO to G2.
No
GO to G9.
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G2 CHECK THE LIFTGATE LEFT/RIGHT PINCH STRIP STATUS (LFT_PINCH / RT_PINCH) OPERATION
- Enter the following diagnostic mode on the scan tool: DataLogger - LTM.
- Monitor the LTM PIDs LFT_PINCH and RT_PINCH while activating the left and right pinch strips.
- Does the PID state change/agree with the pinch strip status?
Yes
GO to G14.
No
GO to G3.
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G3 CHECK THE PINCH STRIP SIGNAL CIRCUIT
- Ignition OFF.
- Disconnect: Pinch Strip (Left C4172, Right C4173).
- Ignition ON.
- Measure the voltage between left pinch strip C4172-1, circuit CPR52 (YE/VT), harness side and ground; and between right pinch strip C4173-1, circuit CPR51 (YE/OG), harness side and ground.
- Are the voltages approximately 5 volts?
Yes
GO to G7.
No
If the voltage measured was greater than 5 volts, GO to G4.
If the voltage measured was less than 5 volts, GO to G5.
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G4 CHECK THE PINCH STRIP SIGNAL CIRCUIT FOR SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: LTM C4174A.
- Ignition ON.
- Measure the voltage between left pinch strip C4172-1, circuit CPR52 (YE/VT), harness side and ground; and between right pinch strip C4173-1, circuit CPR51 (YE/OG), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit(s). CLEAR the DTCs. REPEAT the LTM self-test.
No
GO to G14.
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G5 CHECK THE PINCH STRIP SIGNAL CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: LTM C4174A.
- Measure the resistance between left pinch strip C4172-1, circuit CPR52 (YE/VT), harness side and ground; or between right pinch strip C4173-1, circuit CPR51 (YE/OG), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to G6.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
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G6 CHECK THE PINCH STRIP SIGNAL CIRCUITS FOR AN OPEN
- Ignition OFF.
- Disconnect: LTM C4174A.
- Measure the resistance between left pinch strip C4172-1, circuit CPR52 (YE/VT), harness side and LTM C4174A-25, circuit CPR52 (YE/VT), harness side.
- Then measure the resistance between right pinch strip C4173-1, circuit CPR51 (YE/OG), harness side and LTM C4174A-1, circuit CPR51 (YE/OG), harness side.
- Are the resistances less than 5 ohms?
Yes
GO to G14.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
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G7 CHECK THE PINCH STRIP RETURN CIRCUIT
- Ignition ON.
- Measure the resistance between left pinch strip C4172-2, circuit RPR52 (VT/GY), harness side and ground; and between right pinch strip C4173-2, circuit RPR52 (VT/GY), harness side and ground.
- Are the resistances less than 5 ohms?
Yes
INSTALL a new pinch strip. REFER to Pinch Strip Switch Service and Repair. CLEAR the DTCs. REPEAT the LTM self-test.
No
GO to G8.
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G8 CHECK THE PINCH STRIP RETURN CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: LTM C4174A.
- Measure the resistance between left pinch strip C4172-2, circuit RPR52 (VT/GY), harness side and LTM C4174A-8, circuit RPR52 (VT/GY), harness side; and between right pinch strip C4173-2, circuit RPR52 (VT/GY), harness side and LTM C4174A-8, circuit RPR52 (VT/GY), harness side.
- Are the resistances less than 5 ohms?
Yes
GO to G14.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
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G9 CHECK THE DETENT AND FORKBOLT SWITCH PIDs
- 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)
- 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. The liftgate can be placed in the unlatched position by lifting up on the liftgate handle.
- Begin with the liftgate in the open position, then slowly close the liftgate into each of the latch positions specified by the table below.
a If detent switch is active in the fully unlatched position, manually attempt to rotate the forkbolt toward the latched position.
- Do the switch states agree with the table?
Yes
GO to G14.
No
GO to G10.
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G10 CHECK THE OPERATION OF THE DETENT AND FORKBOLT SWITCHES
- Ignition OFF.
- Disconnect: LTM C4174A.
- Measure the resistance between LTM C4174A, harness side and ground at each of the connector pins and each latch position specified by the chart below.
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 chart?
Yes
GO to G14.
No
GO to G11.
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G11 CHECK THE DETENT AND FORKBOLT SWITCH GROUND CIRCUIT
- Disconnect: Liftgate Latch/Unlatch Assembly C4339.
- Measure the resistance between power liftgate latch/unlatch assembly C4339-8, circuit GD149 (BK/GY), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to G12.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
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G12 CHECK THE DETENT AND FORKBOLT SWITCH CIRCUITS FOR AN OPEN
- Measure the resistance between power liftgate latch/unlatch assembly C4339, harness side and LTM C4174A, harness side using the following chart:
- Are the resistances less than 5 ohms on all circuits?
Yes
GO to G13.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
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G13 CHECK THE DETENT AND FORKBOLT SWITCH CIRCUITS FOR A SHORT TO GROUND
- Measure the resistance between LTM C4174A-5, circuit CPR64 (VT/OG), harness side and ground; between LTM C4174A-4, circuit CPR65 (BU/GN), harness side and ground; then between LTM C4174A-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. CLEAR the DTCs. REPEAT the LTM self-test.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the LTM self-test.
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G14 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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