Reverse lights inop, 04 Automatic

[AHolbert]

I don't have a shop manual for this truck and I'm kinda short on time right now but I have inop reverse lights on my truck. No other issues with the truck and all other lights work fine. Fuses and bulbs were checked and I checked for electrical power with the truck in reverse and have no power in the backup/reverse light sockets.

Before I start taking things apart, what else can I check ? I did a quick forum search and I'm only finding references regarding the reverse switch on the manual trucks. Do I have a similar switch on my automatic ?

Thanks in advance.

 

[p-Bar]

Yes you have a switch on the trans for the B/U not sure if it's in the loom of wires coming out of the trans or a stand alone wire . Stupid question did you check the fuse(s)

Edit there is a six wire plug the wire should be Tan/Grn tracer

 

[AHolbert]

Yes, I checked the fuses. That was the first thing I did..........

 

[p-Bar]

I edited the post so read on

 

[AHolbert]

The six plug wire loom is where, the transmission ? What controls the switch function for the reverse/back-up lights ? In other words, if there is no power on the tan/grn tracer wire, I have a switch issue of some sort ?

 

[p-Bar]

It probably goes to the ecm. I dont know if it's 12volts 5volts or ground. Check it with a volt meter

 

[cerberusiam]

Pretty sure it is 12V at the range sensor and that is the switch to activate the backup lights. Power to range sensor then to the lights.

 

[AHolbert]

Pretty sure it is 12V at the range sensor and that is the switch to activate the backup lights. Power to range sensor then to the lights.

I had time for an online search this morning regarding the range sensor and it looks like it's on the back of the transmission.....

Doesn't seem to be very much specific online information regarding range sensors, pcm, tcm, and all the different control module variations of these earlier third generation trucks with the 48re. I just need to get under the truck and see how mine is configured but it's raining here this morning and there's no room in my garage at the moment to get her inside, besides, I'm about out of time and need to get to work. Good thing is that the only abnormal issue I'm having is the lack of backup/reverse lights and not all the other stuff some people have experienced.......Lack of info must mean lack of problems........

At this point, I'm guessing it's my range sensor or maybe wire continuity, can't get to the truck right now but ya'll have given me a better understanding and I appreciate the help fellas ! I did have my transmission bomb'd (Goerend) so maybe I'll get lucky and the connector just needs to be reseated or there's a little bit of crud or corrosion on one of the pins......

If I narrow it down to the range sensor, do you have a recommendation as to brand or vendor for replacement and anything specific to be aware of in replacement procedure ? From the one schematic I could find it looks to be a simple remove and replace with minor fluid loss ? I'm coming up with part # 56045489ac Transmission Range Sensor for about $65.....

Thanks again !

 

[cerberusiam]

The range sensor is on the drive side of the trans towards the front of the trans right behind the shift lever. They will leak internally and cause issues. It is relatively easy to replace with minimal fluid loss as you found.

 

[Ozymandias]

Those sensors are crap, replaced mine now the third time within 40000M, they leak always oil into the cable harness.