B1976

B1976-POWER LIFTGATE LATCH RELEASE - RATCHET SECONDARY SWITCH PERFORMANCE





For a complete wiring diagram, refer to the Wiring Information.

- When Monitored:
Whenever the power liftgate is fully open.

- Set Condition:
The ratchet switch and pawl switches are closed while the secondary switch is open.





1. DIAGNOSTIC TROUBLE CODE (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.

1. Using the scan tool, record and erase DTCs.
2. Turn the ignition off, wait 10 seconds, then turn the ignition on.
3. Operate the power liftgate several times if possible.
4. Using the scan tool, read ACTIVE DIAGNOSTIC TROUBLE CODE (DTC)s.

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 the BODY VERIFICATION TEST. Body Verification Test.

2. BINDING LIFTGATE
1. 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.
2. Manually operate the liftgate of a known good vehicle and notice the effort needed to open and close.
3. Compare the effort needed on the disabled liftgate.
4. 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 the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 3

3. POWER LIFTGATE MODULE
1. Using the scan tool, monitor the SECONDARY RATCHET SWITCH CLOSED.
2. Using a screwdriver, click the latch to the first detent while observing the scan tool.
3. Unlatch the latch by pressing the handle switch and observe the scan tool for a change of state.
4. 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?

Yes

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

No

- Go To 4

4. CHECK THE (Q901) LOGIC GROUND CIRCUIT FOR AN OPEN




1. Turn the ignition off.
2. Disconnect the Power Liftgate Latch harness connector.
3. Measure the resistance between ground and the (Q901) Logic Ground circuit.
4. Wiggle the harness while observing the ohmmeter.

Is the resistance below 9.5 Ohms?

Yes

- Go To 5

No

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

5. CHECK THE (Q76) LATCH SECONDARY POSITION SENSE CIRCUIT FOR A SHORT TO GROUND




1. Measure the resistance between ground and the (Q76) Latch Secondary Position Sense circuit.
2. Wiggle the harness while observing the ohmmeter.

Is the resistance below 10000.0 Ohms?

Yes

- Repair the (Q76) Latch Secondary Position Sense circuit for a short to ground.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 6

6. CHECK THE (Q76) LATCH SECONDARY POSITION SENSE CIRCUIT FOR AN OPEN




1. Disconnect the Power Liftgate Module C2 harness connector.
2. Measure the resistance of the (Q76) Latch Secondary Position Sense between the Power Liftgate Module C2 harness connector and the Power Liftgate Latch harness connector.
3. Wiggle the harness while observing the ohmmeter.

Is the resistance below 2.0 Ohms?

Yes

- Go To 7

No

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

7. CHECK THE (Q76) LATCH SECONDARY POSITION SENSE CIRCUIT FOR A SHORT TO VOLTAGE




1. Turn the ignition on.
2. Measure the voltage of the (Q76) Latch Secondary Position Sense circuit.
3. Wiggle the harness while observing the Voltmeter.

Is there any voltage present?

Yes

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

No

- Go To 8

8. POWER LIFTGATE DRIVE UNIT




1. Disconnect the Power Liftgate Drive Unit harness connector
2. Erase DTCs.
3. Turn the ignition off, wait 10 seconds, then turn the ignition on.
4. Using the scan tool, read DTCs.

Does the scan tool display this DTC?

Yes

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

No

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