ACC/FCW/cruise/radar issue?

BHAMDOC1973

MEMBER
2012 DODGE CHARGER
V8
2WD
AUTOMATIC
85,000 MILES

It worked once after I drove three miles and cruise worked but I still cannot get it to work again, keeps saying repair radar, no codes other than what is here, which I believe have mothing to do with that. The picture with lots of codes I believe was from when battery was so low but I replaced battery so all should be good, deleted codes and none are back. I am sure all these are related: acc, cruise and FCW. Does not have parking sensors on the front.

Images (Click to make bigger)

1 Reply

STEVE W.

MECHANIC
13,029 POSTS

ACC-FCW are the Adaptive Cruise Control and Forward Collision Warning systems. They use a radar sensor in the front of the car to detect the distance between your car and the one in front. The common reason for this error is that the radar gun in the front is out of adjustment or the sensor is blocked. To adjust it you need a special tool that allows you to aim the unit with the car on a flat surface and then you use a scan tool with the correct driving pattern to adjust it horizontally. You should be able to access it for signal testing with that scan tool though, that would at least tell you if it were still operational.
The first thing I would do is disconnect the sensor and check the connection for corrosion or damage. It is located in the lower valance panel behind the trim cover. Also look at that as painting it with the wrong paint can cause the cruise to stop working as well. Attached are the sensor image and location. The sensor is set on adjustable ball end pins and if you need to replace it you simply pull it with a hard yank to pop it free, then you replace the retainer clips when installing the new sensor.
There is also a TSB about the sensors that gives more info on alignments and issues. It is number 31-003-12.

Images (Click to make bigger)