The "module" controls the engine so the car is disabled if it is disconnected.

They're almost bulletproof so suspect everything else first.

 

It looks like you are right as the two front O2 sensors go to the ECU. As be it the ECU runs a multitude of other things like, (eg) Throttle Body, Air Condition, and loads more of which other things are running as they should. Paramount Specialist have booked my friends car in for next Thursday, if they cant find the problem then god knows who can. Thank you.

 

[QUOTE=test point;1354883]After all the rebuilds and after checking the wiring connections I would look at the ECM itself.[/QUO

This Thursday my friends XK8 is to be investigated by Paramont, hopefully they will come up with the answer of what is wrong. Enough is enough of not knowing what the problems relate to. These cars have too many electronics in them, its not the person who drives it, its the computer that does it for you. Ridiculous.
Let you all know the outcome. Bye for now.

 

It's about as ridiculous as having a smartphone and saying it contains too much electronics. Yeah... for compelling reasons.

 

Hi, It was taken to Stratstones not Paramont as I said, The Two O2 Sensors that was replaced by my friend was not the right ones as the Auto Tech had said, he said they are not sending the right voltage to the Computer/ECU, these are after market Sensors. Fitted Sept.
Then on Friday 04/12/2015 he said that the ECU is faulty and needs either a reconditioned one or a new one. God knows the price of new at this time. Stratstones will let him know if they can get one as the XK8 is 16 years old.
I think that if the ECU is faulty that have been for some time, it could be that all these fault codes that have been known, are being thrown out by this ECU/Computer thats faulty. When a new one is fitted it could be that all related problems before may not have exisited at all.
Please let me know what you think? Thank you.

 

I hope they are not just attempting to thowing parts at it, hoping for a fix. That being said, an inexpensive route is to send the ECU to a rebuild service such as ASI and have it tested. I don't know what services are available on your side, but even if you have to ship it here, the cost should not be excessive.

Automotive Scientific Inc. | Quality Rebuilt Automotive Electronics | Rogersville, TN

 

Thanks, Stratstones had the car for two weeks, a new ECU was installed and two Jaguar O2 upstream sensors installed. It took them all this time to get things right, However last Wed 23rd of Dec my friend picked it up and all was fine. He run the car from Wed to Monday this week and done just over 200 miles and it was running great.
Monday evening he took a friend in the car and things are now back to how it was before the repairs, Limp Mode, ABS Warning Light, Restricted Performance, Traction Control. My friend used his hand held Diagnostic machine and it came up as 1) P0121 2) P1646 3) P0124.
No 1 I think is Throttle Body related, No 2 is the O2 Sensor Bank 1, No 3 is the TPS. So today its being taken back to Statstones and they will put their Diagnostic Machine on it to see whats what. Its an absolute nightmare. I will give you the outcome. Bye for now.

 

I would like to know how the "wrong" lambda senors got installed. Apparently the plugs are different for the different sensors which might be legitimately confused for this application.

 

Just a thought - have the engine fuse boxes relays been checked ....?
Has a hard reset been done after the parts were fitted...?

 

The sensors stated by Stratstones are wrong, what they said that the Voltage is not correct for the ECU. They were fitted with no problem as they are for this 1999 xk8, However, these are after market ones and they have been sent back to get a refund. Thanks.

 

All relays and fuses etc are what they should be, the New ECU had been programed to this XK8. As it is that all new or reconditioned parts have to be collaberated/configured to a ECU anyway as Stratstones had stated.
The Diagnostics where done yesterday and a fault came up as being the TPS, However, we aint sure yet if replaced but it still goes into Limp Mode. Today its being looked at by them today. Fingers crossed. Bye for now.

 

This still sounds like a throttle body issue. Get it fixed properly by ASI, then try again

 

As of previous posts, A new ECU and New Upstream Sensors were fitted in the first two weeks of Stratstones having the XK8 1999. However, the car was run by them and then returned to my friend. My friend run the car to just over 200 miles without any problems. Then on Monday 28th it went into Limp Mode again and Stratsones had it back on Wed 30th.
They said that its the TPS that has a perminant fault, they now said to my friend to get a new or reconditioned Throttle Body. Why is this that on the 03/12/2015 when they first had the car did not say this then instead of putting in a new ECU AND O2 Sensors?
There has been no change in his car whatsoever from the start and have charged him just over £4000 for what they have done. Now they want more to what they think will correct the problem. Please let me know what you think if you have the time. Thank you.

 

With all respect, and feeling sorry for the problems you face, this is a perfect example of no one knowing what they are doing, and happily charging you / your friend for their experiments.

It proves also that as an owner, you simply cannot trust anyone, and that it is necessary to make a step back sometimes, ask advise, FOLLOW UP ON THAT ADVICE, and go from there.

Seems you guys have been going way too fast in allowing others to take advantage of you.

Sorry, I can not help you, but you might take a deep breath, start reading your first posts, and do some head scratching before you let anyone throw an other couple of thousands on the car.

Good luck.

 

Didnt you mention earlier that the TB had been reconditioned (for which I presume your friend was charged a not inconsiderable sum) ?
If so there must be some sort of warranty, if any component is faulty it should get repaired at their expense ?
The P0121 and P0124 codes specifically relate to the TPS, which would reasonably imply a faulty sensor which should have been replaced at the rebuild....

P0121 Throttle Position Sensor/Switch A Circuit Range/Performance Problem


P0124 Throttle Position Sensor/Switch A Circuit Intermittent

 

Thank you, Yes the TB was given to another Jag Specialist that my friend used over years, However, the TB accordingly to this chap said he sent it off for testing and then had it back. Once on return he then fitted it on and there was no change, he then sent it back to have an extended re-test and on return there again is no change. As you mentioned why aint the PPS and or the TPS changed on the rebuild or reconditioned as I call it.
My friend dont trust him anymore. I think its good to get a new TPS off Ebay @ £32.50 and present that to Stratstones. Your thoughts will be much appriciated. Thank you.

 

If the TPS is the Denso 198500 3250, these cannot be bought separately - its a long standing issue (scandal, considering the safety issue of sudden engine failure) of which there are many forum threads relating to it - you have to buy the entire TB (another footnote in the great Jaguar V8 *****-up saga). However there is one dealer on Ebay (UK) selling these for around £220 brand new, so say £235 with the gasket + swap out labour/calibration will hopefully finally nail the problem. I'm sorry your friend is £4k down already without a solution - the parts already replaced may well have been faulty too - and he's now in the unenviable position of having spent more than the car is "worth" to keep it running and is way past the point of junking the car.
Good luck...

 

Thanks, the TB on EBay which I enquired about giving the car details is £1560 being new. Stratstones price with discount is £1350. How will I know about the TPS is a denso sensor etc? On eBay it's £32.50 of after market and 12mth warranty. Please let me know. Bye for now .

 

This is the link to the TB :

NEW GENUINE JAGUAR XJ8 XK8 XJR XKR Throttle Body Assembly C2A1470 | eBay

The sensor I had not come accross before, aftermarket but definitely worth a try....?

 

Time to seek legal advice I think, not any more work on the car till then.