hi guys,

my dads car is an Xtype.


the parking sensor has stopped working - sometimes!


if you put the car in reverse, not always the reverse light comes on? subsiquently when the light doesnt come on, neither does the parking sensor.

when you select reverse, and the reverse light comes on the parking sensor sounds.


there is no water & the unit in the spare wheel well looks brand new & no water damage there, and ive checked all fuses in the glovebox.


any tips?

 

Lude, the reverse sensor system is set up to activate on the reverse lights getting power. So, based on what you are describing, it sounds like your tranny position sensor is starting to bite the dust. if you want some electrical checks to make to confirm the results, let me know. How are you with using a multimeter?

By the way, welcome to the forums. You will find lots of useful information here. So, please, stick around, drink a cup of Joe and see what the site has to offer. I think you will find tons of very useful knowledge here. We also ask that you properly "introduce" yourself in the New Member forum. It helps us get to know you and you will find a few niceties with it too. So, please, stop by and make that second post.

 

thanks mate, have just made my second post in the New member section

i have a multimeter yes, and can use them.

where is the tranny position sensor? is it on the gearbox or isit in the car by the selector?

if you can advise what/how to test it, then i can just replace if its that yes?


thanks in advance for your reply, forums are a godsend

 

Lude, first, I want you to try switching relays R15 and R17 from the fuse box under the dash. Now, attempt to turn on both your fog lights and you high(main) beams. Do these work as they should? If no, you have a bad relay, replace the relay in the R15 spot. Verify that the back up lights/parking aid sensors work as they should. If the parking lights/parking aide sensor do not function as they should, return the relays to where you found them.

Next, turn the car to the "RUN" position, but do not start the car (ensure the e-brake is on fully). Now, find fuse F79. If you look on the top of the fuse, you will see 2 small metal pieces sticking out the top. With the reverse lights not working, I want you to place the black lead against bare metal of the body (or any good ground on the car) and then place the red lead on each of these posts (1 at a time). Did you get 12 VDC on both posts? If you got 12 VDC on 1 post, but not the other, you have a bad fuse, replace the fuse. If you got 12 VDC on both posts, you have a wiring problem inside the dash of the car and unless you are good with wiring, it is sounding like you will need to go to a shop to have them fix it. If you did not get 12 VDC on either post, please do the following.

Remove relay R17 from is socket in the fuse box. Look on the relay, you will see numbers 1 through 5 and them referencing the posts of the relay. Note which posts those are and then find those same spots inside the fuse box. Now, place the black lead of the multimeter to the chassis ground and then place the probe into the slot for Pin #5. Do you get 12 VDC? If no, you have a wiring problem between the passenger fuse box and the engine bay fuse box, seek a wiring shop to fix this for you unless you think you can hand over hand the wiring and find the problem yourself. If you did get 12 VDC on pin #5, move the red lead over to Pin #1. Do you get 12 VDC there? If no, again, you have a wiring problem between the passenger fuse box and the engine bay fuse box. If yes, then set the multimeter to monitor for resistance on the 2K scale. With the car in REVERSE, do you get a low resistance (probably around 500 ohms) but when you take the car out of reverse, the multimeter goes to overload (OL on the screen or some very high resistance). If you see this happening, you have either a bad relay or a problem with the posts inside the passenger fuse box for relay R17. If you are not seeing the resistances change (remaining high at all times), then proceed with the following after replacing relay R17 in its proper spot.

You will need to open the hood of the car and locate the tranny position sensor on the side of the tranny. It will have a 10 wire plug attached to it. Disconnect the plug from the tranny position sensor. Locate Pin #7 (green wire going into it) on the plug. I want you to take a piece of wire and short between that pin and the chassis of the car (any bare metal spot you can find). Do the reverse lights turn on and off as you stick the wire in and out? If yes, then you have a bad tranny position sensor. If no, you have a problem with either the tranny computer, the instrument cluster, or the interconnecting wiring and without specialized training and computers, you will not be able to fix it, so, you will need to take the car into a shop to have them fix it for you.

Make sure that once you are done, everything is returned to how you found it. Hopefully this will get you back on the road. On a side note, this is assuming you have an automatic tranny. If you have a manual tranny, let me know as this will change the troubleshooting that needs to happen. You didn't mention in your original post whether you have a manual or auto tranny, so, I made a guess.

 

My back up sensors were working fine until this weekend, now they seem to come on as soon as I put the car in reverse. Next time I start the car and put it in reverse they don't come on unless there is something in back of me. Strange setup. They were doing this last year before I replaced the battery, I did check the battery and it is fine. As I wrote strange setup

 

This is sort of out of season, but... ;-)

But I had a similar thing happen last winter when I backed into a parking space and got too close to a pile of snow (i.e., backed into the pile...). When I returned to the car the rear sensor alarm started ringing when I started the engine. I expected it to stop when I pulled out of the space but it didn't. Annoyed me all the way home until I got out and saw the snow pushed onto the sensors. Cleaned them and all was fine.
================================================== ====
Jaguar - it's not an automobile, it's a Motorcar

 

Interesting story. I didn't mention but my sensors started acting up after I cleaned them. I used a microfiber cloth with plain water and cleaned each one. Then the continues beeping started. I thought clean was good?

 

Here is a TSB for Resetting the 'J'-Gate.

bob gauff