I have a 2007 Chrysler Pacifica Limited which throws a SERVICE PARK ASSIST message after putting the car in reverse.

As part of diagnosing the problem I took the car to the dealer and they said two of my parking sensors were bad (but didn't say which ones). I used the technique suggested here (put an object very close to each sensor, shift to reverse, and note what the LEDs do) and thought I had identified the two bad units.

I ordered replacements but I still get the same LED failure pattern.

I'd like to test these independently before moving back through the electrical system since the Park Assist module is only available secondhand. The dealer was unable to get codes from the module and declared it "bad" but that's a separate post for another day.

Can anyone identify the pinout and how I might test whether the sensors are good? I have a multimeter and an adjustable power supply.

Parking Sensor

  • Do the same test, but just replace places of a working sensor with non-working sensor and see if the problem migrates or stays in the same place. If the non-working sensor starts working, then you will know that you have another problem somewhere else, perhaps cabling etc. In that sense, it is not important to know how to test the sensor with multimeter as long as at least one of the sensor place is working. Mar 9, 2017 at 21:48

1 Answer 1


You may want to use a scope, the type of signal it sends to the control module is unknown. Though if you can pick up anything it may show the sensor is OK. Another thought would be to set your multimeter to Hz.

If you can have someone read codes off the park assist module and it'll give you a better idea of what's going on.

The Pinout:

Pin 1 - Supply voltage (Gray/Orange)
Pin 2 - Sensor signal
Pin 3 - Ground (Gray/Light Blue)

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  • Unfortunately the dealer wasn't able to get codes off the Park Assist module. They think the module is bad, but I think it's related to the backup lights and camera not receiving power, which is a separate question. Mar 8, 2017 at 15:51
  • @WildcatMatt May be, try power cycling the control unit (unplug it for a minute) and see if it comes back to life. Then you can test your power and grounds while you're in there.
    – Ben
    Mar 8, 2017 at 18:49

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