Reverse Sensors

[dglick]

I have a petrol 3.0 v6 S-type sport 2003

The rear parking / reverse sensors appear to have packed in.

Have checked the fuses which appear to be in order.

My handy engineer neighbour suspects it will be as simple as changing a switch - but doesnt know where to locate it - can anyone please advise ?

[piman]

Hello Dglick,

quite a common fault, it could be the reverse aid module, located in the spare wheel well due to water ingress, or faulty detector(s).

If you switch the ignition on, select reverse gear and listen to each detector in turn, if working they emit a clicking sort of sound, you need to be very close or do as I do and use a piece of pipe as a sounder (easier than getting down to the ground) Alternatively is there anyone you know who has a code reader to help with analysing the fault.

I'm a recent owner of an X Type and found that nothing electrical is simple.

Alec

[J44EAG]

Check first for a water flooded boot. The control module lives there and if drowned will stop working.

Most sensor issues are down to poor connections. Road muck and corrosion often need cleaning away. The two outside sensors are just abought reachable by sliding a thin arm up the sides of the exhaust boxes....but only just. The inner units are impossible to get at without removing the rear bumper cover. A Torque app on an Android or Iphone and a bluetooth ELM327 OBD chip or an iCarsoft 920i or other diagnostic gear can tell you which unit is defective. Alternatively with ignition on and reverse selected, placing an ear to each sensor in turn will reveal a ticking sound from units which are still working. A non ticker is obviously a unit which has a problem. Cleaning is the first stage, If that doesn`t restore normal function, then a replacement sensor will need to be sourced. Buy only genuine Jaguar units. Costs are around £30 per unit.

The issue is not only confined to the S-type. Other Jaguar models also suffer the same issues. almost all Jags will suffer this issue at some point in their career on the road.

Mike K

[Montana5]

Also try cleaning and re-connecting Plugs into Module.
http://www.jec.org.uk/forums/viewtopic.php?f=283&t=5216

Doug.

[thomas45]

I have been there, done this , that and the other but then decided to purchase a retro kit with the intention of just replacing the sensors.
This would be easy (I thought) wont need the hole cutter supplied nor the rest of the kit. Wrong! I soon discovered that I could not get them out without removing the bumper or doing damage.
However, the decision was made and the complete kit was implemented so now I have possibly the only S Type in the world with eight sensors on the back. Drastic yes but not really noticeable and working very well with both a speaker and visual distance guage mounted on the dash.

[jeff1954]

I'm having problems with my rear park assist. As in sometimes when reverse is selected I get a continuous bleep even though there is nothing behind. I have disconnected and re connected the wires from the unit to no avail. Any ideas anybody?

Jeff

[J44EAG]

From time to time I get this on my 350. The long bleep indicates that a sensor fault is present. My iCarsoft unit itemised at one time that there was a fault with a sensor, one at the front and one at the back.

Initially weather dependent, the fault would come and go. As I planned to remove each bumper in turn to clean the sensor connections, the fault would cure itself. So I would put the tools away and the fault would come back!

Soon after, I came to replace the battery which was continually loosing the fight. That seemed to cure the fault completely unless the car had been used for a few short journeys, in which case the fault would occasionally re-occur.

With the benefit of having run two different S-types and a 350 for some eleven years, I`ve formed the opinion that both battery voltage stability and dirty sensor connectors have a similar impact on sensor reliability. If connections are dirty, this could cause a resistance hotspot and lead to reduced voltage at that point. Similar an unstable and failing battery can cause a similar effect. I now have a Bosch Silver battery fitted which is rated at a slightly higher 100ah capacity an is I am told to be regarded as a "premium" quality unit. I still get the very occasional long bleep but it is vastly less often than when I had the old battery fitted.

As yet I have not removed the bumper cover to clean sensor connections which is down to my own reluctance to cause pressure on a sciatic nerve affected leg in so doing. I know how irritating the sensors can be when the long bleep glitch comes out to play. So far, I have learned to live with it.

Mike

[jeff1954]

Thanks for that Mike. I'll try the iCarsoft rout as I hadn't thought of that and see where we go from there. The battery is in good condition and not under much stress at this time of the year.
I'll also try and get to the sensor connectors behind the bumper as well.

Jeff

[jeff1954]

My 2004 model has a black valance at the bottom of the rear bumper cover. This comes off separately from the bumper cover. Once this is removed you can gain access to the two inner sensors from underneath without removing the whole bumper cover. The two outer sensors can be accessed by removing the rear light clusters.

I did this job yesterday, now all I need to do is sours a new sensor which I think are quite expensive.
The joys of owning a Jag!

Jeff

[J44EAG]

Ensure you buy only genuine Jaguar OE parts.. It is quite common to find after-market copies that do not work.

Use only a couple of light spray paint coats when colour painting these parts. Too much paint applied may cause issues. Halfords will mix you coded spray paint if you give them the three letter code found on the plate inside the front passenger A-post door shut.

Mike K

[jeff1954]

Thanks for that Mike. I spoke to someone at DMG today and they supply two sensors, a Jaguar one at about £73.00 and and an after market one at £26.00. When I asked them why it was cheaper they said that they buy them direct from the manufacturer and it doesn't come in a Jaguar box ect. I wonder if they are both of the same quality?

Jeff

[J44EAG]

That is the problem. With the OE units you know that the electronic internal gubbins will be a proper match. With any other type you take a chance on them not being correctly matched to the highly sensitive Jaguar electronics.

Might be worth asking Manners if they have had any complainants with the after-market units.

Having had problems with non Jaguar aftermarket electronic parts in the past. I`ll not take a risk on compatibility any longer. I loath having to do repairs twice!

Mike

[jeff1954]

The plot thickens. I have replaced the faulty sensor with a new one but still getting a continuous bleep when reverse is selected All the sensors are ticking individually when I put my finger over them. When I use my icarsoft it says there is a circuit failure on the new sensor which I know is working. It also says that there is a configuration issue with the module.

I have disconnected and reconnected the 3 plugs to the module and also disconnected the battery for about 15 mins but to no avail. Any ideas anyone.

Jeff

[J44EAG]

It is worth exercising the plug on the module box despite having all sensors ticking. Not an issue that I`ve yet seen as regards all ok but not ok....... Very odd indeed.

Mike

[jeff1954]

Looks like its a faulty sensor (the new one that is) as on closer inspection one of the three electrical contact pins on the sensor itself is shorter than the other two. So a replacement is being sent out. I will let you know the outcome.

Jeff

PS Your 350 is looking great Mike.