Hello everyone,

I hope some of the more experienced user could help me shed more light on this:

This morning on a motorway, om my way to work, I've floored the accelerator from about 110 km/h to overtake another vehicle and engine immediately shut down with the following intermittent messages on the dashboard:
1. Engine Systems Fault
2. Parkbrake Fault
3. DSC Not Available

After couple of minutes on the hard shoulder, I've started the engine, only the Parkbrake Fault amber light remained on, so I continued driving to work, not going above 2,000 RPM and everything was fine.
I've checked the codes on my Phone scanner tool (ELM327 Bluetooth+Torq app) and got these codes:
1. P0222
2. P1122
3. P1215
4. P1344

Now, from what I could find on this forum, all of these fault codes point to a faulty Throttle Positioning Sensor.
If that is correct, what is the connection to the Parking Brake and DSC?

Any thoughts on what I am faced with here?

Additional info (not necessarily relevant - if at all -to the issue described above):
2004 Jaguar XJR with 290,000 km on the clock
Have been having issues with lean codes (P0171, P0174) for a year now - couldn't find a vacuum leak - work in progress
During the last month I had my transmission and TC rebuilt (serious slipping 3rd-4th, 5th-6th) and replaced all solenoids on the valve body 2 day ago.

Cheers,

 

I had this problem on my 4.2 NA and had to replace my throttle position sensor. When that fails it tends to raise all those faults and warnings on the dashboard. I know on supercharger models, like you have, the throttle body is at the rear of the engine and the TPS can get wet and causes it to raise these faults.

 

Thx for the reply

This is in line with everything I've read on this forum.
Can somebody confirm the position of these 2 sensors? Are they both attached to the throttle body?
Has anybody had a positive experience in purchasing these two sensors from the online vendors (separate from the whole throttle body)?

 

Some folks have had success changing out TPS - and on the NA 4.2 up to late 2005 they were exchangeable. I am not as familiar with the rear mounted throttle body. Later models required the TB replaced as a unit when the made the TPS integral. I did see an issue with the Throttle itself (The gas pedal has a rheostat on it as well), creating a complete drive by wire setup.) People that did change the TPS has a tough time calibrating it (Most tried just marking the position of the old one where it bolts on, not the most precise method obviously. My 06 AND 07 have these faults pop once in a while, usually under a lot of throttle/shifting/cruise control changes. I have been lucky enough to shut the ignition, wait a minute and restart fault free, but it of course worries me that eventually my luck will be discontinued as these cars were.

You could attempt the TPS swap, and go for a rebuilt Throttle Body as plan B, or just go for the TB if time is more pressing. Before going there, you might get some relief by using some throttle body cleaner and even some electronic cleaner on the setup. Often the plug on the TB get pertly disconnected from heat and age. Be careful not to break any connections if you can. Good luck either way.

 

Thanks Blairware

That's exactly the course of action I was thinking of following:

1. Try with a TB Cleaner, check the electrical contacts and if that doesn't work, then
2. Get a new TB - from what I've seen they can be had for around 400 USD from online vendors - which isn't too expensive.

I will be skipping the TPS swap as finding a good piece seems to be hit and miss (I am in Kuwait, so returns are out of question) and aligning it properly, seems too fiddly with uncertain results, so not worth the effort in my opinion

Either way I will report back on the outcome.

Cheers

 

Make sure it's not the battery. I had a similar issue and it was a dead cell in the battery. It's simple to check - fully charge the battery, wait an hour or two and then load test it. If you're lucky, that might be all it is. Good luck with it.