With no warning, luckily on my street, my 2003 XJR went into monster limp mode. It is showing the yellow engine light, both yellow and red warning lights, Trac Control and ABS warnings and Restricted Performance warnings. So I pulled the Codes and it is showing me these;

P1000 (Normal I think)
P1111 (Normal I think)
P1121 Pedal Position Sensor
P1642 Canlink Circuit

I think those are the right definitions for the codes. So it looks like my throttle position sensor has gone out on the car. I followed the linkage up behind the dash and I don't know where the sensor is. Any clues and is it relatively easy to get to or should I take it to a dealership to change.

Where can I get the part other than at the dealership.

The car has been rock solid until now, so this is not an issue other than potential costs.

Thanks,

Eric

 

the dreaded P1121 - It's either a new or refurbished throttle body. A hard reset will get it back to normal - but if it repeats, it's as above.

The problem is the TPS on the side of the t-body wears out, the part isn't available.
You can try and clean all the connectors on the body and hope it doesn't come back.

To test...
First remove the induction tube from the t-body - plug the reader in, scroll through to throttle position without the car running but with the ignition on, and either press the gas pedal very slowly to see the percentage go up on the reader, looking all the time at the butterfly opening in the t-body or have someone eyeball it while you press the gas pedal. If it doesn't open fully then it's replacement.

The canlink is related to the signal breakdown within the sensor to the rest of the electrical circuit.

 

Hi
The P1121 DTC issue could be poor electical contact connections on the Trottle Body and showing up as "Pedal position sensor failure" .

Look at this other thread "xj8 problems asc abs trac grearbox fault solutions" (go to post# 12):

https://www.jaguarforums.com/forum/x...02/#post420826

I cleaned the throttle body butterfly and a couple of the sensor plugs and connectors (with throttle body stray cleaner and electrical spray cleaner).

This resolved the P1121 DTC fault. But after 2 weeks, P1122 and P1642 faults started.

These were cleared by replacing the TPS connectors with new gold TPS connectors kit.

The TSB 303-58 on TPS connectors says models 1999-2001 XJ series and 1999-2001 XK range.

You probably do not need to replace TPS connectors, but you should inspect them.

The next week we starting getting recurring P1638 (CAN INST) faults that was resolved after a few weeks by replacing the IPK (Instrument Pack, known as Instrument Cluster Module).

https://www.jaguarforums.com/forum/x...veryday-62726/

https://www.jaguarforums.com/forum/x...84/#post454947

As you can see that I had multiple issues stemming from the P1121 and P1642 DTC faults.

Jim Lombardi

 

Thanks guys for the help. As the issue started after a car wash I may try Jim's ideas first. They are a lot cheaper to deal with as a starting point. After I make sure that the connections are good, then I will try a hard reset, then and only then replacing the throttle body. Any clues as to where I can get one in North America other than paying through the nose for one from the dealership?

Thanks again.

Eric

 

Okay, so I took everything apart and cleaned the connector and the throttle body plate. Put everything back together and started the car. No change. So then I read the codes and they were the same as before, P1121, P1642. So then I tried the hard boot.

I cleared the codes and then tried to start the car. It started fine and no lights and no codes. I then went for a test drive and the car ran great, way better than it had been doing. As I pulled back on to my street the yellow engine light came on and a Restricted Performance warning came up. I also lost the tach. Pulled into the driveway and the car responds to the throttle fine, but all kinds of warning lights and messages including the parking brake warning came up.

So I checked the codes and this is what came up;

P1637
P1638
P1642
P1643
P1797

All are different codes but relate to the CAN system communicating with various parts of the car. Now the car starts and runs fine, but nothing else is running well, LOL. I found a Throttle Body Rebuilder close to me, BBA International. They have a Lifetime warranty on the parts. He will check my throttle body function for me for $35 and then if it needs rebuilding he can do it for me in 3 days.

Seem like decent guys and seeing as Jag wanted to charge me $2800 for the part and 2 hours labour to diagnose the issue and replace the body, I am pretty happy. This is their website and they have operations around the globe,

BBA reman. ABS, ecu's, throttle bodies, air mass meters, and catalytic converters

Fingers crossed that I can get this done for under $700.

Eric

 

Hi
Did you view my video of our XJ8 when we had P1638 DTC fault:
Video showing the flashing warnings & weid sounds

I used the movie record feature on our digital camera to make this video.
It shows what is happening when I turn the ignition key to position II (at this point in the video, I am not even trying to start the engine).

The position II is where the system check takes place, before you turn the key to starting position.

Here is the video on YouTube.com (you can right click on it and then select "Watch on YouTube"):


Jim Lombardi

 

Wow, spacey and cool effects, LOL. Mine is totally behaving properly, just not always after I clear the codes and drive it for a while. I will find out later today if its the throttle body.

Eric

 

Just thought that you guys should know that I had my throttle body rebuilt at BBA Reman in Toronto for $410. Just installed it and the car started and runs great. Not throwing any codes and idles great with stronger throttle response!

All was fixed with a new Throttle Position sensor. Weird how everything corelates but I am pretty happy now. Fixed for under $500 and runs better than before. If you guys are having issues, check with the guys at BBA Reman as they repaired my issue.

Eric