Hi JF,

I hope you can help shine some light on a problem my old man has with his X-type 2001 3.0l Automatic (UK) if it makes any difference. There are 2 issues the 1st being the main one.

1) Basically the reverse lights are always on even when in drive or neutral, I am assuming the fact the parking sensors are on is because they are linked/wired to the reverse lights.

Someone told us that it could be a reverse light switch that is located on the gearbox, looking for this part I can only find them for manual gearboxes and not autos, so don't think this part would apply here.

My thoughts so far are possibly a faulty relay (R17). Unfortunately I have searched most of the day & not found anything regarding this fault on a jaguar.


2) Speedo occasionally will stop working, i.e. driving along and the needle will just go to zero, will have to try multiple engine starts to get it working again.

Any help on a fix or what to check would be much appreciated as the car is pretty much unusable till it is resolved. Thank you for your time.

 

3thanol, first off, welcome to the forums. I think you will find a lot of very useful information here. But we do ask a simple thing from you, please stop by the "New Member" section and introduce yourself. You will find we pride ourselves on being a different level of car club and we like to get to know one another. This will also let you see who the movers and shakers are around here.

As for your problem. I would first start with pulling relay R17 from under the hood. This should kill the backup lights. If it doesn't, then you have a problem with the wiring harness itself and that is going to require professional help unless you are good with wiring, then I would help you through it.

If pulling the relay does kill the lights, then I need you to pull relay R15 (should be the same size relay) and put that into the R17 slot. Does your problem still exist? If no, then you have a bad relay, replace the relay (BTW, R15 is the relay that powers the main beams and the fog lights, you could probably live without that until you can get to the store to buy a new relay). If the problem is still there, then pull the relay back out of slot 17 and do a resistance check between where Pin #2 is on the relay and chassis ground. If this reads a lot resistance (less than 5 ohms), then your problem is confirmed to be either interconnecting wiring or the instrument cluster. Based on the fact that you are having other issues with the instrument cluster (ie, the speedo dropping to zero), I would start with the instrument cluster as that is the most likely thing to be wrong at this point.

As for the speedo issue. First off, do you have the check engine light on (the yellow engine looking symbol in the center of the tach)? If yes, get the code(s) read just to confirm what I am thinking. The code should say something to the effect of "failure of a communication bus". If the light is off, then this helps to confirm that your problem lies in the instrument cluster and you need a new instrument cluster. I say you need a new cluster based on the fact that if the problem lies with another component, the ECU/ECM would be tossing a code that it is not getting all the necessary data. You would also possibly feel a shudder in the car when you apply the brakes (the ABS will not know what to do since the wheels and the speedo are indicating something different).

 

Thanks thermo, I changed over the relays and it did not cure the issue so I have advised my dad to take to an auto electrician. I could carry out the test with a meter but I would be stuck with what to do next. With regards to the speedo a warning light does come on so it would be worth getting a reading done. After speaking to him both faults are a bit more complex then just pulling a relay, so he is gonna get to a electrical technician, Thanks for your detailed response and time to advice me on where to look and check, no doubt I will post a few more questions as his jag is starting to get on.