Hi, posted a few weeks ago about rat damage to some of the electrical on my 2003 XJ8. I got some help and links to manuals that helped me. I now have another issue with the car. I moved it out of my driveway a few weeks ago and it sat there for 2-3 days. When I went to move it back in I got a check engine light, transmission fault, restricted performance message and it banged going in to gear and did not want to move either forward or reverse.

I hooked up my code reader and got a P1121 and P1111 error and that was all. That code relates to the TPS or the PPS but essentially it's pointing to the TB as a problem. The car has 85K miles and had the transmission rebuilt 3,000 miles ago. Up until this failure it ran just fine.

I don't think this issue is related to wiring damage caused by the rats but I cannot be 100% certain. Visual check showed no probs with damaged wires on the TPS or the PPS. I unplugged them and sprayed contact cleaner in both, reconnected and no change.

Pressing the gas pedal does nothing, no change in engine revs. The car idles about 1200 RPM and hunts up and down as it idles. Using live data on my reader there is no change showing on the TP % when I press the gas.

Are there any checks like resistance measurements that I can do at the TB to confirm if it is indeed bad or otherwise indicate that the issue is likely electrical and possibly due to rat damage,

thanks in advance

 

A new tps is available for cheap on eBay. I bought one less than 3 years ago and tried it out in a customers car that needed one and it worked. You need the part number off of your tps and go to eBay and get one. I’m sure Bob will forward you a TSB about the TPS pins but, if you cleaned them and it made no change then you likely need a TPS. New ones weren’t available until about 3 years ago and now they’re available all over eBay.

 

If pressing the gas pedal does nothing, I would check the pps first. Sounds like the ECU is not getting a signal for throttle demand and is not telling the tps where to set the butterfly.

 

I think when in restricted mode computer inhibits (disables) throttle control, so pressing pedal does nothing.

I am in the same situation, got transmission error few times but restarting and plugging/unplugging connections helped. Now I am getting this error too often to drive.

My question why "You need the part number off of your tps and go to eBay and get one." - are there different models? I have 2000 xj8 , it's not the same model for all x308 xj8?

 

There are TWO different throttles. AJ26 and AJ27. They are not interchangeable.(maybe some individual parts are?, never tried it)

 

Thank you! Looks like AJ26 for 98-99 and AJ27 for 00-03, whew.... I ordered TB from 2003 for my 2000 , should work.

 

97/98 XK8=AJ26
98 XJ8=AJ26
98/99 XJR=AJ26
1999-2002 XK8=AJ27
1999-2003 XJ8=AJ27
There are no XKRs in the US prior to 2000MY

 

HI NJ2003XJ8, what did you finally order for your car, was it a TPS or TB?

Regardless of which one you got, did you get your problem fixed?

regards

 

bgilgall, assuming you still have this issue, have you by chance tried performing a hard reset?

 

Yes, I got used TB off ebay. It was easy swap and yes - so far no problems and my confidence in the car is back!

 

in a long run. I would suggest to send the TB for rebuild/repair. you would never know when the new"used" TB is going the fail.

trust me, I learned the hard way. mine is rebuilt (I went further with internal porting thou...)

 

Where did you go for a rebuild? Rought cost?

 

I used this company -ATE. It was a lot less pre-COVID...I still have a repaired TB from them as my spare.

https://www.ebay.com/itm/38316468909...3ABFBM0JbhoO9g

 

not yet. There is damaged wiring that I need to repair first due to rodents. The car did run ok even with the chewed cabling before this happened but i dont want to introduce additional potential complications to the issue. Unfortunately some health issues have slowed me down this year but I'm mostly over those and ready to get the car running again. I have a TPS ordered as a backup and.I'll definitely carry out the hard reset when I've sorted the wiring issues. Is there any else that is involved.with the hard reset procedure? It looks like I need to connect the positive and negative cables together for 15 to 30 secs to drain any capacitive effects and them leave disconnected for 15 mins, thereafter re-connect, start the car and let it run for 30 mins at idle? Thanks for replying to my message.

 

You’re correct about the connecting of the battery cables for about 15 or so seconds.

 

Going through the same issue on my 2001 XJR. The last work I did to mine was to adjust the throttle cable tension to get closer to 100% WOT and I might have gotten too close so I backed it out a bit, now around 93-95% WOT max. Did the hard reset, cleaned the PPS and TPS connectors and cleaned the throttle body before I reconnected everything. Scanner says at WOT I'm fluctuating slightly by a few tenths of a percent so I suspect a TPS might be in my future. I might try a cheapie and see if it resolves the issue before I spend more on a good quality unit that I can't return because most places don't let you return electrical components that have been connected. Right now I jsut need to drive it and see if the error presents itself again.