Hi, the backup\reverse lights and rear parking sensors do not work on my 2005 S Type. Is there a common point of failure for these two items? I am getting voltage at the backup\reverse lights. rear turn signals, brake lights all work. Any tips on troubleshooting this scenario?

Thanks!

 

Wiring diagrams here, courtesy of Gus:

http://www.jagrepair.com/images/Auto...cal-2005on.pdf

See section 18.1 for the parking sensors and 8.3 for the reverse lights.

The two respective modules are both in the trunk. Lift up the trunk floor panel and inspect under the spare tire for water. These cars are notorious for rain water collecting in the trunk and wreaking havoc with the electronics back there.

The other thing to remember is the exterior lights have constant power and (electronically) controlled grounds. This is opposite of most vehicles that have switched power and constant grounds. Don't let that confuse you when troubleshooting.

 

Thanks for the link! looking at figure 18.1, it appears that the the reverse lights need to be Activated in order for the rear parking sensors to operate. So I'll start by taking a look at the rear electrical module. Thank you again for your help and quick reply!

Best,

-Jim

 

Uff da! I missed that connection. Good sleuthing. Most likely the rear parking sensors are fine but aren't receiving the command to operate.

One quick thought: Look at the shifter J-gate when you select reverse. Does the R illuminate? I suspect the same switch for that light also sends the command for the rear parking sensors and the backup lights.