I just discovered that my C5's backup lights are not working! neither comes on when my car is in reverse (6 speed). I have a service manual and I guess I will go through the steps sometime this weekend, but I thought I would ask the forum for any info. many times people here are able to provide solutions to problems which require less time and money than what the service manual says.

here is what I know:
the lights do work, the approach lighting and flash when I lock the car works fine.
those lights didn't work that way for a long time since I had the approach lights fuse pulled in order to disable the DRLs I recently decided to go to a better method of disabling them which I read about here. I pulled the two DRL relays (38 & 40) from the interior electrical center and put an insulator in between the normally open contacts so that when the relays energize the contacts do not close. this prevents the DRLs from coming on. with this done I was able to put back in the approach lights fuse and restore that functionality. I do not know for sure if the backup lights stopped working at that time, but it is an interesting coincidence. its sometimes hard to notice, but I am pretty sure they used to work.
according to the service manual there is a relay related to the backup lights in the underhood electrical center, #38 (not to be confused with the #38 DRL relay in the electrical center at the passenger's feet) they are both fed by the same power source, fuse #2, the approach lights fuse. the power wires running to all three relays (DRL L, DRL R and backup) are the same circuit according to the manual. now this backup relay doesn't seem to turn on the backup lights though. looks like its normally closed contacts feed power through the reverse switch in the gear shifter to the backup lights allowing them to work normally. the normally open contacts connect the backup lights directly to power. this relay is energized by the BCM, so that would be how the BCM makes the lights flash when you lock and come on when you unlock. it just seems to be odd that these two circuits appear to be so closely related. it doesn't look like it from the diagrams, but is there any way that disabling the DRL relays could have had this side effect? I have not checked the fuse which is powering the circuit which runs through the gear shifter yet. I also have not looked up the codes (although there were a few BCM codes last time I looked in there)

if anyone has any ideas or has experience this in the past please give me any info you have! TIA

 

If your back up lights are working the circuits good so its something else.

The easy way to inhibit the DRLs is by pulling fuse #2 in the engine panel. The other way is to fit jumpers between the contacts and pulling the #38 and #40 relays on the other panel. theres a sticky that describes that mod in the Tech Help section.

Not had the problem on the Vert but had trouble with my sons Camaro and the old Explorer.

I'd start with the reverse selector module on the transmission. Its a flimsy part and is known to fail often. Easy change with a wrench and takes about 5 minutes. Take off the connector. Unscrew the old one. be ready with the new one as youll get a little fluid leaking. Tighten up and reconnect.

That would be my bet.

Someone posted this a while ago. It has a pic on the original if you want a copy

Reversing light switch change

Been a while since I replaced mine, but as I recall it's on the right-hand side of the trans.. Hard to miss, it's the only one on the side w/ wiring, unless you have a Z06, then you have wires coming out of the fill plug on the other side as well.

And if the switch doesn't fix it, don't panic; it's typical for the switch to short and take out the associated fuse (only for this circuit.. The backup lights will still flash as you described w/ this fuse blown). Can't remember the fuse #, but I'm sure someone here will.

Switch is on the passenger side on the middle of the tranny. Micro-relay #38 in the underhood fuse panel. Also related is fuse #2 for the Approach Lights in the underhood fuse panel.

 

I had the exact problem on my 2001 6-speed coupe. Turned out to be the reverse light contact. Put the car up in the air, turn on the key (car not running) and put the shifter in reverse. You will need (2) people for this, have one guy watch the backup lights and have the other wiggle the connecter where it attaches to the trans (just pass the rear - if I recall the connector is blue or gray). If they come on/off, tighten up the contacts (which worked for me) or replace as needed

 

thanks for the suggestions! I guess I'll get under it this weekend and see what happens. any ideas how much a new switch costs just in case?

just when I thought I knew of all of my C5's problems!

 

$30 for the Camaro

I posted the pic above

 

well I think I do have a bad switch there. I checked the obvious now that its light out and went for the fuse #21 in the instrument cluster electrical center by the way. fuse was blown! thought I had it covered. I replaced the fuse with my last 10A left and put it in reverse, blew right away. based on what you guys are saying I'm pretty confident that its a bad switch if they are known for shorting when they go bad.

what do you guys think? for $30 should I just get one on order?

 

can someone tell me where the replacement procedure is in the service manual? the diagnostic pages say refer to backup lamp switch replacement, but the only thing in the index is where it tells you how to replace the backup bulbs themselves.

 

ttt...

please?