B1976

B1976-POWER LIFTGATE LATCH RELEASE - RATCHET SECONDARY SWITCH PERFORMANCE





For a complete wiring diagram refer to Diagrams/Electrical

- When Monitored:

Whenever the power liftgate is fully open.

- Set Condition:

The ratchet switch and pawl switch are closed, while the secondary switch is open.





Diagnostic Test

1.DTC PRESENT

NOTE: This DTC will only set during the latching operation after the four second time out. This may make it difficult to reproduce.

With the scan tool, record and erase DTC's.

Turn the ignition off, wait 10 seconds, then turn the ignition on.

Operate the power liftgate several times if possible.

With the scan tool, read ACTIVE DTCs.

Does the scan tool display B1976-POWER LIFTGATE LATCH RELEASE - RATCHET SECONDARY SWITCH PERFORMANCE?

Yes

- Go To 2

No

- Using the wiring diagram/schematic as a guide, inspect the wiring and connectors for an intermittent condition. Operate the door several times and check for any binding or other obstructions.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

2.BINDING LIFTGATE

Examine the liftgate for proper fit and alignment, loose/hard or torn seals, misaligned latch striker or anything that would cause an obstruction to proper operation.

Manually operate the liftgate of a known good vehicle and notice the effort needed to open and close.

Compare the effort needed on the disabled liftgate.

Especially notice the effort needed to unlatch and close the liftgate.

Does it take more effort to operate the liftgate than it should?

Yes

- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 3

3.OBSTRUCTION OR STICKING FULL OPEN SWITCH

Examine the liftgate for proper fit and alignment, foreign material in the drive unit or anything that would cause an obstruction to proper operation of the Full Open Switch.

With the scan tool in Inputs/Outputs, read the FULL OPEN SWITCH state.

Manually operate the liftgate while monitoring the scan tool.

Does the switch status change smoothly as the liftgate is pulled down from the full open position?

Yes

- Go To 4

No

- Replace the Power Liftgate Drive Unit.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

4.POWER LIFTGATE MODULE

With the scan tool, monitor the SECONDARY RATCHET SWITCH CLOSED.

Using a screwdriver, click the latch to the first detent while observing the scan tool.

Unlatch the latch by pressing the handle switch and observe the scan tool for a change of state.

Repeat this step several times while moving the liftgate in different positions and wiggling the harness to check for an intermittent open or shorted circuit.

Did the scan tool show the switch state changing correctly every time?

No

- Go To 5

Yes

- Replace the Power Liftgate Module.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

5.(Q901) LOGIC GROUND WIRE OPEN





Turn the ignition off.

Turn all lights off.

Disconnect the Power Liftgate Latch harness connector.

Measure the resistance between ground and the (Q901) Logic Ground circuit in the Liftgate Latch harness connector.

Wiggle the harness while observing the ohmmeter.

Is the resistance below 9.5 ohms?

Yes

- Go To 6

No

- Repair the (Q901) Logic Ground wire for an open.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

6.(Q76) LATCH SECONDARY POSITION SENSE WIRE OPEN





Disconnect the Power Liftgate Module C2 harness connector.

Measure the resistance of the (Q76) Latch Secondary Position Sense between the PLG C2 harness connector and the Liftgate Latch harness connector.

Wiggle the harness while observing the ohmmeter.

Is the resistance below 2.0 ohms?

No

- Repair the (Q76) Latch Secondary Position Sense circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

Yes

- Go To 7

7.(Q76) LATCH SECONDARY POSITION SENSE WIRE SHORT TO VOLTAGE





Turn the ignition on.

Measure the voltage between the (Q76) Latch Secondary Position Sense wire and ground in the Liftgate Latch harness connector.

Wiggle the harness while observing the voltmeter.

Is there any voltage present?

No

- Replace the Power Liftgate Latch.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

Yes

- Repair the (Q76) Latch Secondary Position Sense wire for a short to voltage.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test