B197A-POWER LIFTGATE LATCH RELEASE - SECTOR SWITCH PERFORMANCE
For a complete wiring diagram Refer to Section 8W
- When Monitored:
Whenever the power liftgate is performing a power opening or latch releasing operation.
- Set Condition:
The sector switch is unstable during a latch releasing operation.
| Possible Causes |
| BINDING LIFTGATE |
| LATCH NOT IN HOME POSITION |
| (Q901) LOGIC GROUND CIRCUIT OPEN |
| (Q79) SECTOR SWITCH SENSE CIRCUIT OPEN |
| (Q79) SECTOR SWITCH SENSE CIRCUIT SHORT TO VOLTAGE |
| (Q79) SECTOR SWITCH SENSE CIRCUIT SHORT TO GROUND |
| (Q79) SECTOR SWITCH SENSE CIRCUIT SHORT TO THE (Q901) LOGIC GROUND |
| POWER LIFTGATE LATCH |
| POWER LIFTGATE MODULE |
Diagnostic Test
1. DTC PRESENTNOTE: This DTC will only set during the releasing operation after the four second time out. This may make it difficult to reproduce.
With the scan tool, record and erase DTCs.
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 B197A–POWER LIFTGATE LATCH RELEASE – SECTOR SWITCH PERFORMANCE?
Yes
- Go To2
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. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
2. BINDING LIFTGATE
NOTE: If the liftgate fails to open manually, refer to service information. (Refer to 8 - ELECTRICAL/POWER DOORS - DIAGNOSIS AND TESTING)
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
- Refer to Service information for the related symptom(s).
- Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
No
- Go To 3
3. LATCH HOME POSITION
Ensure the liftgate is closed.
With the scan tool in Inputs/Outputs, read the “Sector Gear Switch Closed” state.
Does the scan tool display TRUE?
Yes
- Go To 9
No
- Go To 4
4. POWER LIFTGATE LATCH
Disconnect the Power Liftgate Latch harness connector.
With the scan tool, monitor the Sector Gear Switch Closed.
Connect a jumper wire between the (Q79) Sector Switch Sense circuit and the (Q901) Logic Ground circuit.
Repeat the previous step several times by disconnecting and connecting the jumper while observing the scan tool.
Did the scan tool show the switch state changing correctly every time the jumper was connected and disconnected?
No
- Go To 5.
Yes
- Replace the Power Liftgate Latch.
- Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
5. CHECK THE (Q901) LOGIC GROUND CIRCUIT FOR AN OPEN
Turn the ignition off.
Turn all lights off.
Measure the resistance between ground and the (Q901) Logic Ground circuit.
Wiggle the harness while observing the ohmmeter.
Is the resistance below 9.5 ohms?
Yes
- Go To6
No
- Repair the (Q901) Logic Ground circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
6. CHECK THE (Q79) SECTOR SWITCH SENSE CIRCUIT FOR A SHORT TO GROUND
Measure the resistance between the (Q901) Logic Ground circuit and the (Q79) Sector Switch Sense circuit in the Power Liftgate Latch harness connector.
Wiggle the harness while observing the ohmmeter.
Is the resistance below 100.0 ohms?
No
- Go To 7
Yes
- Go To 11
7. CHECK THE (Q79) SECTOR SWITCH SENSE CIRCUIT FOR AN OPEN
Disconnect the Power Liftgate Module C2 harness connector.
Measure the resistance of the (Q79) Sector Switch Sense circuit between the Power Liftgate C2 harness connector and the Power Liftgate Latch harness connector.
Wiggle the harness while observing the ohmmeter.
Is the resistance below 2.0 ohms?
No
- Repair the (Q79) Sector Switch Sense circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
Yes
- Go To 8
8. CHECK THE (Q79) SECTOR SWITCH SENSE CIRCUIT FOR A SHORT TO VOLTAGE
Turn the ignition on.
Measure the voltage of the (Q79) Sector Switch Sense circuit.
Wiggle the harness while observing the voltmeter.
Is there any voltage present?
No
- Replace the Power Liftgate Module in accordance with service information.
- Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
Yes
- Repair the (Q79) Sector Switch Sense wire for a short to voltage.
- Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
9. ADJUST LATCH TO HOME POSITION
Close the liftgate.
With the scan tool run the “Latch Home Position Test”.
NOTE: This test will try to adjust the sector gear to the Home Position.
With the scan tool in Inputs/Outputs, read the “Sector Gear Switch Closed” state.
Does the scan tool display: FALSE?
No
- Go To 10.
Yes
- Repair complete.
- Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
10. CHECK THE (Q79) SECTOR SWITCH SENSE CIRCUIT FOR A SHORT TO THE (Q901) LOGIC GROUND CIRCUIT
Disconnect the Power Liftgate Latch harness connector.
Measure the resistance between the (Q901) Logic Ground circuit and the (Q79) Sector Switch Sense circuit in the Power Liftgate Latch harness connector.
Wiggle the harness while observing the ohmmeter.
Is the resistance below 1000.0 ohms?
No
- Replace the Power Liftgate Latch assembly and with the scan tool run the “Latch Home Position Test”.
Yes
- Go To 11.
11. CHECK THE (Q79) SECTOR SWITCH SENSE CIRCUIT FOR A SHORT TO GROUND
Disconnect the Power Liftgate Module C2 harness connector.
Measure the resistance between ground and the (Q79) Sector Switch Sense circuit.
Wiggle the harness while observing the ohmmeter.
Is the resistance below 1000.0 ohms?
No
- Replace the Power Liftgate Module in accordance with service information.
- Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
Yes
- Repair the (Q79) Sector Switch Sense circuit for a short to ground.
- Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).