B12B1

B12B1-23-TRUNK EXTERNAL SWITCH - SIGNAL STUCK LOW

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

Theory of Operation

The Liftgate is controlled as a third door, so when the doors are locked the Liftgate is also locked, and when the doors are unlocked the Liftgate is unlocked as well. When the Liftgate is unlocked, it can be opened by means of the button on the external handle. If the trunk is mechanically opened, it's logic state does not change, and when closed again it automatically aligns with the status of the other doors (Locked/Unlocked). The Liftgate cannot be opened with vehicle speed over 13 mph, to prevent accidental Liftgate opening.

- When Monitored:
Whenever the Body Control Module (BCM) is awake.

- Set Condition:
When the trunk (liftgate) switch is stuck for over 30 seconds, this code will set.





1. TEST FOR INTERMITTENT CONDITION
1. Turn the ignition on.
2. With the scan tool, record and erase the DTCs.
3. Try to open and close the trunk (liftgate) several times.
4. Wait 30 seconds.
5. With the scan tool, read the active DTCs.

Does the scan tool display; B12B1-23-TRUNK EXTERNAL SWITCH - SIGNAL STUCK LOW?

Yes

- Go To 2

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals and correct pin tension.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. LIFTGATE RELEASE SWITCH
1. Check the Liftgate Release Switch for anything that may cause a sticking condition. Repair if necessary and re-check the DTC. If okay, continue testing.
2. With the scan tool, erase the DTCs.
3. Disconnect the Liftgate Release Switch connector.

NOTE: The Liftgate Release Switch is in the License Lamp Bar Exterior Handle. Exterior Handle Lamp Bar - Removal .

4. Turn the ignition off.
5. Wait 30 seconds.
6. Turn the ignition on.
7. With the scan tool, read the active DTCs.

Does the scan tool display; B12B1-23-TRUNK EXTERNAL SWITCH - SIGNAL STUCK LOW?

Yes

- Go To 3

No

- Replace the License Lamp Bar. Exterior Handle Lamp Bar - Removal.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

3. (P30) LIFTGATE RELEASE SWITCH SENSE CIRCUIT SHORT TO GROUND
1. With the scan tool, erase the DTCs.
2. Turn the ignition off.
3. Disconnect the Body Control Module C2 harness connector.
4. Measure the resistance between ground and the (P30) Liftgate Release Switch Sense circuit in the Liftgate Release Switch Sense connector (Cavity 2).

Is the resistance below 10K Ohms?

Yes

- Repair the short to ground in the (P30) Liftgate Release Switch Sense circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Replace the Body Control Module. Body Control Module - Removal.
- Perform the BODY VERIFICATION TEST. Body Verification Test.