My 2004 XJR is about to put me in the Insane Asylum. For about a month now the Cruise, DSC, Trac Powersteering, Speedometer, Transmission have operated and malfunctioned at random intervals. According to the codes it is the Wheel Speed sensors on both rear wheels. (i replaced the passenger rear less than a year ago). THeyve been taken out, Cleaned and put back in to no avail. and as of today the Air Suspension has decided to do its own thing. All of the sudden while driving along the ride became Violently bouncy and stiff. Too the point of almost loosing control of the car at 40mph. the Rear end Lifted about 9 inches up as the compressor pump ran wild. (i replaced the right rear air shock with an Arnott the week i baught the car in Nov of 2013.) I have no idea what to do with this thing. I literally am contemplating leaving the windows down with the Keys in it next time i go to Wal Mart and let nature take its course. This is by FAR the worst vehicle i have Ever owned and i have owned several Turds in my life. I should have known when the NADA value drops $68,000 in less than 10 years that there was probably Good Reason for it. I wont trash jags any further because i know so many of you love your own. Any similar experiences or ideas about this?

 

Sounds to me you have an electrical problem which needs sorting. I understand your upset but only a thorough search will help at this point. First, hows your battery? Tested?

Guus

 

The battery is just under a year old. i Changed it out just before i changed the wheel speed sensor. I just drove it and the air suspension went back to normal. Occasionally the Trac and ABS lights go away but re appear after 10 minutes or so... its almost like some connection is loose somewhere

 

Given the multiple issues, it would be helpful to have all the Diagnostic Trouble Codes reported to us inorder to help you sort things out.

Without the benefit of that, it will be a lot of guessing on everyone's part.

I know you are frustrated, but if you read forums of other high-end sophisticated cars you'll find out that it doesn't matter if it's a Lexus, BMW, Mercedes or whatever, some owners have flawless operation, and some owners have nightmares.

Once you have a system of a dozen computer modules and multiple communication networks layered on top of the normal complexity of the automobile, stuff is gonna happen. Think about it, when was the last time you used a computer that didn't have something go wrong in a few years, let alone 11 years? Individual car components are far more reliable than prior generations, but car systems are so much more complex that it adds exponential means for something to go awry.

Off the top of my head, I might wonder about water ingress as a source of your woes. If you lift the hood, you'll see two covers on the cowl towards the windscreen. Lift those up to look down into each and see if either drain is blocked. Check the trunk around the spare and see if there is any water in there.

Second, even though the battery is a recent a replacement, that doesn't necessarily mean it isn't the source of the problem, or at least a clue. Are the connections clean? Are the ground points clean? etc. It used to be that the first sign of a battery or alternator problem was trouble starting the car, now the first sign is weird behavior. So don't be too quick to dismiss that as a potential fault.

Finally, you mention that the speedo has had some issues. The Instrument Cluster is a key communication hub between several modules, so that might be something to consider. However, that brings us back to the DTCs. If you post those, everyone can perhaps be more helpful in having ideas of what might be the heart of your gremlins.

 

Well well, i may have cured the air suspension activity. Earlyer today i just happedend to clean out the trunk and for somereason decided to peep in the spare tire compartment. And what did i see but about 3 inches of standing water. So now that im reading your post you were right on the money. im afraid i am the cause of this water...when i changed out the battery there was a rubber tube attached to it. The new battery didnt have the place to attach the tube so in my ignorance i just left it hanging. Well from what i can figure that Tube is a water line that channels rain water to top off the water level in the old Battery. Its been raining here for several weeks and appearently it has been filling the entire compartment. (Thats a nifty feature to keep your battery topped off but it seems like a risky idea to put any type of water source soo close to the Electricals back there ).... anyway i pulled the drain plugs and dried everything out with a leaf blower. the Elec connections on the Modulator for the air system were partially submerged but i think they are ok. The Air Suspension is acting normal so far. I will check the front tomarrow and have the codes read again. Are there any fuses by any chance that would have anything to do with the Speed sensing system? I also got a 'Restricted Performance" message today for the first time.

 

If you have signal but erratic it is not likely a fuse. Curious about the codes.

Guus

 

That isn't the source of your water in the trunk. The tube is to vent off gassing from your battery so it doesn't collect in the trunk area with corrosive effects.

You might want to read this:

https://www.jaguarforums.com/forum/a...1-07v2-htm-pdf

 

P0171, c1165, p0701, p0101 are the codes that came up at autozone.

 

Thanks for that Link! I started inspecting the water channels and saw that the drain holes at the top of tail lights were both clogged. I took the black plastic panel off inside the trunk and saw where the water had ran down into the spare tire well. It appears that since the drains up at the tail lights were clogged the water pooled and overflowed into the interior edge of the trunk lid where it flowed down and went behind that black plastic panel. Since it went behind he panel the carpet never got wet and i never knew what was happening untill i looked in there.
Ithink the air suspension problem is solved now that everying has dried out. The trac dsc abs and cruise control malfuntions are still there but now the warning lights dont come on untill about 10minutes after startup.

 

Check the earth strap under the headlights, if bad it causes a whole host of electrical funnies,

regards

Andy

 

P0171= Bank 1 combustion too lean
Engine misfire
Air intake leak between MAF Sensor and cylinder head
Fuel filter / system restriction
Fuel injector restriction
IP Sensor fault (low fuel pressure)
Low fuel pump output
HO2 Sensor(s) (1/1, 1/2) harness wiring condition fault
EFT Sensor fault (low fuel temperature) MAF Sensor fault (low intake air flow) Exhaust leak (before catalyst)
ECM receiving incorrect signal from one or more of the following components:
ECT Sensor, MAF Sensor, IAT Sensor, IP Sensor, EFT Sensor, TP Sensor

p0101 = MAF Sensor circuit range / performance
Blocked air cleaner
Air intake leak
Engine breather leak Throttle control malfunction
MAF Sensor to ECM sensing circuit:
high resistance, intermittent short circuit to ground
MAF Sensor supply circuit: high resistance
MAF Sensor failure
Throttle adaption fault (check throttle position voltage at Ignition ON)

p0701 = TCM control errors
CM / control valve failure
Dynamic Stability Control system fault

c1165 = Dynamic Stability Control
RH rear wheel speed sensor circuit: open circuit, short circuit to B+ voltage, short circuit to ground, high resistance
RH rear wheel speed sensor failure

I looks like you have two separate issues, an engine problem and a problem with the DSC.

Guus

 

Note that the earth/ground studs are aluminum and riveted to the aluminum body, so the torque specification for the nuts is a very low 6.5 ft.lb. Several members have snapped their ground studs off, so take care to just get the nuts snug.

 

I changed the airfilter oit and that didnt solve the engine prob. I can hear a sucking sound somewhere under the plastic sheilds of the engine, at first i thought it might just be a supercharger sound but its pretty pronounced like a vaccume line or something. Im going to pull all the dang plastic covers out that i can and inspect it further.

As for the ground strap for at the headlights, how do i get to it? I have noticed lately at night when im comming to a stop or turning at an intersection that the passenger side headlight will flicker on and off. So they may verywell be something loose there.

I drove the car for about an hour today and the. dsc abs cruise control warning lights never came on. The Trunk is totally dried out now. There are soooo many electricals back there that were wet or exposed to that much humidty im Hoping thAt maybe the dsc trac wheel sensor gremlin may have been due to that. I dont know. I will check it all out when i get home and try to get the codes scanned again now that those warning lights have ceased to see if anything has changed
Thanks!

 

I took off the engine cover and removed the MAF sensor, cleaned it with the spray from Autozone and put it back. I let it run and listened close and looked it over with a flashlight to see if there were any vacuum leaks. I think its ok. There is a noise that sounds like air but im pretty sure its just air moving through the superchager apparatus. I drove it back to have it rescanned, all the dsc,trac, abs, problems have stopped and the warning lights are gone. It feels like its running great, but the CEL is still on. Well they rescaned it and get p0171 again. P0101, c1165, c1175. Idk if these are just still being stored in the cars brain or what. I had unhooked the battery for about an hr and touched the cables for 10sec in hopes of resetting before getting it rescanned, and Autozone wouldnt clear the codes and start over because of thei 'policy'.... Ive read a couple threads that have mentioned it might be a bad Throttlebody sensor that could cause the p0171 along with the dsc, restricted performance messages