B1975

B1975 - POWER LIFTGATE LATCH CINCH - RATCHET SECONDARY SWITCH PERFORMANCE

B1975 - Power Liftgate Latch Cinch - Ratchet Secondary Switch Performance:

WHEN MONITORED
Whenever the power liftgate latch is performing a cinching operation.

SET CONDITION
The ratchet switch is unstable during a cinching operation.

POSSIBLE CAUSES
- Binding liftgate
- (Q901) Logic ground circuit open
- (Q76) Latch secondary position sense circuit open
- (Q76) Latch secondary position sense circuit short to voltage
- (Q76) Latch secondary position sense circuit short to ground
- Power liftgate latch
- Power liftgate module

Diagnostic Test

1. DTC PRESENT

NOTE: This DTC will only set during the cinching 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.

Q: Does the scan tool display B1975-POWER LIFTGATE LATCH CINCH - 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.

Q: 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. 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.

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

NO: Go To 4
YES: Replace the Power Liftgate Module. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

4. (Q901) LOGIC GROUND WIRE OPEN




Turn the ignition off.
Turn all lights off.
Disconnect the Power Liftgate Latch connector.
Measure the resistance between ground and the (Q901) Logic Ground circuit in the Liftgate Latch connector.
Wiggle the harness while observing the ohmmeter.

Q: Is the resistance below 9.5 ohms?

YES: Go To 5
NO: Repair the (Q901) Logic Ground wire for an open. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

5. (Q76) LATCH SECONDARY POSITION SENSE WIRE SHORT TO GROUND




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

Q: Is the resistance below 10000.0 ohms?

NO: Go To 6
YES: Repair the (Q76) Latch Secondary Position Sense wire for a short to ground. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

6. (Q76) LATCH SECONDARY POSITION SENSE WIRE OPEN




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

Q: 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 connector.
Wiggle the harness while observing the voltmeter.

Q: 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