First, if there is a trailer hitch on the car, remove it. If the problem persist, further diagnosis is necessary.

In most cases, the fault codes are sensor related. Several cases of cut or damaged wires in the bumper covers have also been reported. If all wires are in good condition, try to switch sensors positions. This will determine if the problem is wire or sensor related.

In this example, the rear right sensor fault is present.

  • Disassemble the rear bumper cover to get access to sensors and wires*.
  • Inspect the wiring. If no damage is found, go to the next step.
  • Take the rear left sensor and connect it to the right and vice-versa
  • Clear the PAM faults using the IIDTool.
  • Start the engine and select reverse gear**.  If the audible warning is present, go to the next step. If not, you might have to play around with it until it comes back.
  • Shift the transmission in park.
  • Read the PAM faults using your IIDTool.

If the error is still on the right side, this will confirm a wiring issue. If it is now on the left side, it is related to the sensor itself.

* Videos showing the procedure are available on YouTube: How to remove rear bumper on…

**The vehicle must be outside. Make sure there’s no object behind the vehicle which could trigger the system.