I have a 97 jag xk8 I've sent throttle body out to asi and it still stalls saying traction control fail fail safe abs light on I already xyanged computer spark plugs throttle body fuel pump got another computer gauges my codes were saying tos sensor I had original computer sent out to be fixed they found a malfunction on board but said if don't get electrical issues fixed at same time it will keep happening but I put original computer back in same codes the codes I'm getting are p1000 p1229 p0117 p1226 p1242 I also got a different computer spark plugs wires new battery fuel pump gauges any suggestions ad I'm at a complete loss and so is my mechanic and u can't buy a tps sensor anywhere I have 2 throttle body's and 2 computers the original I had fixed but no changed it won't stay running stalled any suggestions would be appreciated jodi

 

I hope I can help here please?

It is just a little bit of electrical infidelity and will sort itself out.

When I have disconnected the battery for long term storage then run the car again I get the ABS light on and error messages.... traction control fail..stability control fail... don't worry it is a battery issue and not a problem. Drive the car for a few miles and then stop. After a couple of drives they go away.

Take care xx

Smitty

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Hi I sent in original computer to be fixed same issues got new battery new throttle body gauges spark plugs fuel pump no change the codes are p1000,p1229,p0117,p1226,p1242 any advice

 

Sorry can't help with the stalling problem but the Nikasil Cylnder linings may have been stripped by the high sulphur content in petrol in the 90s. I hope this is not the case, otherwise the engine has had it. You need to get the engine looked at by Jaguar and if the Nikasi linings are gone they will still replace the engine I believe.

 

Thanks for the advice but car won't even stay running to drive it any more suggestions anyone from codes and everything I've replaced and done thankvu

 

Hi Jodimarie,
Let's see if we can't break this down into smaller bites:

For the time being, you can ignore the traction and ABS errors. These can be the result of a low battery.

By computer (there are several) I guess you mean the Engine Control Module, or 'ECM'? The '97 ECM is prone to issues which cause driveability problems, so having it repaired is not wasted as most seem to fail sooner or later, and the repairer states that issues were found. It may or may not be part of the problems now.

Here is a snip from the Jaguar 97 DTC list for those codes:


I have not included P1000 as that means that the car hasn't completed its emissions diagnostics yet. That will change to a P1111 once the car is happy, so can be ignored for now.

P0117 may be simply that the engine coolant temperature sensor is disconnected (the connector has a plastic tang that breaks off allowing it to come apart), or the wiring has an issue.

The other three P-codes could be ECM-related, but you've had it repaired & also see the same codes with a replacement module?


I would start with point-to-point wiring checks between the ECM and the throttle body.

Note the TPS on the early cars is an electronic rather than mechanical device. I've not read of any true failures, unlike later cars (post-98).

What gauges have you replaced & do you have cruise control?


edit: P1240 default action is the same as P1229

 

I would not waste your time with mechanics who know nothing.

This is most definitely a Nikasis engine cylinder lining failure. Firstly, the auto transmission NEVER stalls... the problem is that the engine cylinder linings have been eaten away causing loss of compression and no power.

Jaguar in the 1990's, like BMW and Mercedes used ceramic coating to line the combustion chambers or cylinders. It was a compound of Silicon and Nickel... Nikasil. It was very resistant to heat and used in racing cars, a good idea. Unfortunately people used the cheap shitty supermarket petrol instead of the premium stuff that Jaguar recommended. It has changed now due to regulations but the high sulphur content in the cheap **** reacted with the Nikasil and stripped the linings causing compression loss and failure.
Jaguar replaced them with steel lined cylinders under warranty.
Sorry history lesson over, it does not help you.
My honest advice is forget about phoney mechanics, go straight to your main Jaguar dealer and tell them you have a failed Nikasil engine and ask if they will replace it.
I feel sorry for you but they will replace it hopefully.
It was a great engine but broken by cheap shitty gas full of sulphur.

 

You are telling me they will replace the engine on a 25 year old car with 100,000 + miles?
Which fairy tail book have you been reading. It would be cheaper for them to scrap the car and give you £3000

 

Easiest way to establish this is to have a compression test. If the cylinders are OK then Michael's assessment looks correct, he knows a lot more than I do about ECU error codes etc. Either way I can't see it being a cheap fix.

 

Your car has the first version of the AJ engine which is the AJ26. That engine was replaced by the AJ27 in 1999, which is the engine in my 2000 XK8. The workshop manual for the AJ27 engine gives you step by step instructions on how to diagnose OBD2 codes. There is a seperate workshop manual for the AJ26 engine which should help you diagnose your code issues. I believe you can get a PDF version here for free. I am not familier with the AJ26 manual but hopefully it is a comprehensive at the AJ27 manual.. Good luck.

 

I agree that the mechanic is probably out of his depth. I can't concur with a Nikasil failure, though.

Received wisdom these days is that, if the motor has 'made it' so far, it will continue to perform.I also doubt that failing compression would throw throttle-related codes:- misfires, perhaps?

As you say, a compression test (or better still, blow-by test) will settle that either way.


It was getting rather late when I posted last night (too hot=couldn't sleep), so I've done a little digging in the EG this morning.

Interestingly, it states this:



So, the MAFS (it says IATS, shows MAFS on the diagram), coolant temp sensor & all the throttle sensors share a common ground, supplied by the ECM.

Also, all the throttle sensors share a common 5V reference supplied by the ECM.

I'd definitely investigate the wiring around both of these.


Here's an old thread I came across from Delirious, with somewhat similar symptoms. In his case, the ECM was faulty.

https://www.jaguarforums.com/forum/x...unning-151759/

 

Jodi,

Sorry to hear things still aren’t working smoothly despite all the work you have had done on the car.

A quick run down on your DTC codes -
P1000 a nothing to worry about now - just a check status
P0117 - coolant temp sensor - maybe bad wiring in the sensor’s connector. It’s located at the top of the coolant tower at the front of the engine. Easy to get to and check.
P1242,1226 - both together seem to point to a problem with the throttle body and related sensors/limits. What engine as maybe different set up for the A27 & A26?

 

I would check the grounds, in particular the main ground from the negative terminal of the battery.
I would also check the two big fuses in the high amperage module in the trunk, both for continuity and to see if they are tight.
Finally, there is a large braided metal ground strap under the car. I'd check that too.
Then, if the car still doesn't start or stay running, I would run the code reader again.
Still throwing a lot of varied codes and you have tried replacing various sensors/throttle body, etc.?
Ok, then do a compression test.
But do you really want to know your engine is shot? At least until you have tried less expensive remedies?
By the way, I've avoided the dread compression test on my '97. It might be the cause of the odd warning lights the car throws, but I don't want to know. The car is 25 years old. That's like 50 in Japanese car years (though I recently saw a late 90s Camry pull into my friend's auto shop with a hole in its block - still running though.)
Anyway, our 25 year old cars can run just fine, even with the Nikasil block.
But it's been my experience that the oddest, and sometimes most obvious problems, will result in a poorly running car.

 

Oh... Jodi has 2 threads?

In the other I suggested after seeing Davids post (got the threads mixed up)... An easy check is to have a good look at the coolant temp sensor and it's wiring. I'm a day late dollar short...

 

You're not going mad.... Graham copied the posts across from one to the other to try to keep it all in one place.