What does it mean?
B1966 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Power Liftgate Sensor Supply High .
Symptoms
- Power liftgate refuses to operate and reverts to manual use
- Group of liftgate sensor codes stored together rather than a single sensor fault
- Gate stops mid travel or will not accept a command at all
- Repeated chime when a gate cycle is requested
- Fault present continuously rather than only in wet conditions, when a hard short is involved
Likely causes
- Sensor supply wire chafed against a switched or permanent battery feed inside the gate loom
- Water in a connector bridging a power pin to the reference pin
- Damaged sensor allowing its internal supply to be pulled up
- Incorrect repair or splice putting a feed wire onto the reference circuit
- Terminal pushed into the wrong cavity after a connector repair
- Faulty voltage regulator inside the liftgate control module
- Poor module ground, which raises every measured voltage referenced to it
How to fix it
- Measure the reference voltage at the module and at a sensor connector, and compare the two readings
- Unplug the module and check whether voltage is still present on the reference wire, if so the short is external to the module
- Isolate the harness section by section to find where the feed is touching the reference circuit
- Check the module ground with a voltage drop test before condemning its regulator
- Look for previous repairs, splices and mis inserted terminals in any liftgate connector
- Inspect the sensors themselves by disconnecting each one and rechecking the reference
- Repair the wiring fault or replace the module when the reference is still high with everything else disconnected, then clear the codes and verify a complete gate cycle