Range Rovers Forum banner

Reverse lights on in wrong gear

3K views 28 replies 4 participants last post by  Blobthebuilder 
#1 ·
Hey peeps, I have odd problem, when I select park I get reverse lights on but I think that's the cable needing an adjustment but it also on in gear 3 and 2, car runs fine with no errors just this, its a 1996 2.5 dse automatic
 
#2 ·
Does the dash and the LED next to the shifter show the correct gear? The reversing lights are turned on by the BeCM when the oiutput from the XYZ switch on the side of the gearbox is showing it to be in reverse. As the XYZ switch also drives the dash and LEDs, then I would expect those to be showing wrong too.
 
#5 ·
It shows the indicated gear light at gearbox but nothing on dash, I recently had problems were it was sent away twice to be coded to ecu and key and now everything is working except this problem and sunroof and I don't really want to send it away again its literally running perfectly, the reverse in park I know is cable underneath because when I disconnected it earlier and pulled rod few more mm light went off but its the reverse in 3 and 2 I find annoying even though I havnt used then I know about it lol
 
#6 ·
If the LED next to the gear lever is reading correctly, then it should also be displaying what gear you are in next to the odometer, like on this pic



Where it's showing I'm in Park. The wiring from the XYZ switch which controls what is displayed on the dash and which LED next to the gear lever is lit, runs from the switch to the gear lever with a splice off it under the centre console which then goes to the BeCM and gearbox ECU. The BeCM then tells the dash what gear to display and, if you are in reverse, switches on the reversing lights, while the gearbox ECU checks to confirm that the gear set by the mechanical cable and the switch are the same. If they don't match then you will get a Gearbox Fault message and it will go into limp mode.

It isn't the cable that needs adjusting to stop the reversing lights coming on in park, it is the XYZ switch that needs rotating on it's mounts to get it correct.
 
#8 ·
+1 Richard. Blob, do you have access to a nanocom? It will let you read the underlying xyz switch state. If the switch is playing up it will do unpredictable things. Not heard of no gear sign on the Dash before though.
 
#12 ·
ok - so then I think the switch orientation maybe ok - in which case it's the electronics. Do you ever have starting issues (ie key turn, and no engine response) as if you were trying to start when in gear? (Dodgy xyz may send an "in gear" signal to Becm even when you're in park). Does your dash NEVER display a gear selection ?
Ideally needs to get on a nanocom - where are you?
 
#14 ·
ah ok, so nowhere near London then. Ideally you need diagnostics, else you'll be chasing your tail. Presumably the reverse lights will come on without the engine on (but ignition on), and by just moving the gear selector ?
If the front wipers are on, and you engage whichever gears are putting the reversing lights on, does the rear wiper now come on? This would be further confirmation that the BECM thinks reverse has been engaged (ie not some other weird wiring issue).
C325 (2,9) is the outgoing connector on the BECM for the reverse lights. More interestingly C626 (8,9,18) carries the incoming xyz signals, if you have no nano you can confirm that each microswitch is working by reading these pins (the manual has a table in it which will give you the switch combinations necessary for the becm to read each gear)
 
#16 ·
interesting...

I don't have the answer, but what I would be trying is looking for the +ve voltage that's getting to the reversing lights . For the reverse lights to be specific to position of the gear lever though it really still points at the xyz switch. I would test the outputs of that first at C626, and the signal form the BeCM at C325.
It's a bit weird that there's no gear selection at the dash - that's beyond my experience. The rest of the display text works? Did "they" do anything funky to your BeCM ?
 
#20 ·
It never displayed before becm went away and no the mirrors don't dip in any gear bud I just tryed the trailer connections white plug on left and pink cable on right and they all live in park, reverse, 3 and 2, I was wondering if the gear selecter indicator is removed could I get to the led for reverse then I would disconnect cable for reverse lights in boot and run connection to led so there only on in reverse or maybe a switch what is the law regarding rear lights/reverse lights
 
#21 ·
It'll take you longer to work around than find the problem, but no I don't think that wd work. I'm no auto electrician, but this is not a manual where you can intercept a simple reverse switch/ circuit, and the Led you refer to is in an Ic on the deck of the selector. I did strip it down once, unlikely you cd do anything from there imho.
I would try finding a friend with a nanocom, or acquire one. Until then it's just you a probe, and the electronic troubleshooting manual, as suggested above.
If you fancy a punt on eBay, then pick up a working xyz switch (watch the part number) and see what happens. Worst case you'll have a useful spare, best case you'll fix your issue.
 
#22 ·
It's an early car so could be different and had it been a 2.5DT I could have thought the gear being displayed on the dash might not be enabled but a DSE is the diesel version of an SE spec. Unlikely it would have dipping mirrors anyway as that was only on the HSE with electric memory seats. Definitely an odd one, you need to find out where the power to the reversing lights is coming from.
 
#24 · (Edited)
Just got back from a run in mine and when putting it into gear I suddenly realised. When would you ever put it into 2 or 3 anyway? Except when towing when I might occasionally drop it down into 3, the rest of the time I only ever use P, D and R so the reversing lights coming on with 2 and 3 would never happen.
 
#25 ·
You cd depin the connector to the reverse lights ( if you're sure it's not part of the MOT,) and then add in a 2 pin connector with an inline switch and then plug the other side if the switch into the empty slots in the becm connector, but personally I wd be doing some diagnosis first before devising a work around.
Nanocom can test reverse lights via becm, so I suspect the becm might also register no load as bulb failure...law of unintended consequences...
 
#28 ·
MoT testers manual para 4.6.2, (MOT inspection manual: cars and passenger vehicles)

You must inspect all reversing lamps fitted to vehicles first used from 1 September 2009 other than quadricycles and Class 3 vehicles.
Reversing lamps must show a white light to the rear. On some vehicles it may be necessary to have the engine running before the reversing lamps will work.
At least one reversing lamp must be fitted.

Reversing lamps not working is a fail

But as I pointed out a couple of posts ago, when do you ever use 3 or 2?
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top