Hey everyone. A mechanic friend and I finally got around to reassembling the 2004 XJR after changing out the valley hose, other hoses, and replacing fuel injectors. The car ran a bit rough on start up for a few seconds as expected when changing out the injectors and the idle smoothed out pretty quickly then after a couple minutes of idling I get the "Systems fault, DSC not available, Parking Brake Faults along with 6 codes.

Each time I turn car off let it sit a while then start it back up the Engines Systems fault,DSC not available, Parking Brake Fault go disappear but always come back on within a couple minute of idling. Does this point to the Throttle body 4 prong sensor?

I am also getting the following 6 codes...

P0300
P0303
P0304
P1316
P0205
P1229

I had a different 04 XJR and have experience the Systems fault,DSC not available, Parking Brake Fault codes in the past while driving. I ended up fixing the other XJR by unplugging the Throttle body 4 prong sensor, spraying wd-40 in the connector then plugging it in and out a few times. Unfortunately that trick did not fix it on this Jaguar.

Any ideas or input greatly appreciated.

 

P0300 Random Misfire Detected
P0303 Cylinder 3 Misfire Detected
P0304 Cylinder 4 Misfire Detected
P1316 Misfire Excessive Emission OR could be Injector Driver Module Codes Detected
P0205 Cylinder 5 Injector Circuit / Open
P1229 Throttle Motor Control Circuit Malfunction

The DSC Not Available, Systems Fault, etc, messages on the dash will be from the P1229

 

Hi hawaiianjag,

It sounds like it would be worth re-checking all the electrical and fuel rail connections that were disconnected or may have been disturbed during your work. You have codes for misfires in cylinders in two different banks, and it's unlikely two coils failed while you were doing your work. The P0205 code may just mean the cylinder 5 injector is not connected securely.

The DTC Summaries manual explains all the fault codes and gives possible causes and you can download it here:

X350 DTC Summaries Manual

Another thought is that WD40 leaves behind a residue of oil that adds electrical resistance, so it is not the best choice for cleaning connectors, especially for something as sensitive as the throttle position sensor. Most auto parts stores carry zero-residue electrical contact cleaner spray for this purpose.

Cheers,

Don

 

Thanks Cambo and Don. Your time is very much appreciated.

The only code we were getting initially before we took on this job in the first place was "cylinder 5 misfire". So we decided to do a visual inspection, swap all the fuel injectors out and of course the hoses under supercharger while I was at it. So it is good to at least see that I don't have a cylinder 5 misfire code anymore although we do have a code related to cylinder 5 again(P0205 Cylinder 5 Injector Circuit / Open)

My moto mechanic friend that's been helping me with this job had said all the connections to the injectors looked fine and everything seemed normal when we replaced the injectors so might there be anything that we should be looking for? Perhaps there are tests we can do to the injectors/electrical connectors to make sure all is working properly?...do the connectors or wires to the injectors on these ever go bad?

I'm okay with replacing some things that may not even be the case now but could be in the future while we have this thing torn apart AGAIN since it is such a pain in the *** to get that far into her so anything you might suggest should be replaced is appreciated.

Thanks again everyone

 

Hi hawaiianjag,

I wouldn't worry about replacing any parts just yet. You only had one code before you did your work and now you have six. It is unlikely that a bunch of parts failed while you were doing the work. It is far more likely that some things have not been properly reconnected.

If you study the Possible Causes for each code in the DTC Summaries manual I linked to they will give you some direction for your investigations.

Please keep us informed.

Cheers,

Don

 

Thanks Don,

We have the XJR disassembled again down to the fuel rails. Nothing seems out of place after inspection. I see listed possible causes of a misfire as per the DTC pdf you sent me as:

-ECM to ignition coil primary circuit fault (Cylinder misfire detected DTC also flagged)
-Fuel injector circuit fault(s) (Injector DTCs also flagged)
-Ignition coil failure
-Spark plug failure / fouled / incorrect gap Cylinder compression low
-Fuel delivery pressure (low / high)
-Fuel injector(s) restricted / leaking
-Fuel injector(s) continuously open
-Fuel contamination
-Worn camshaft / broken valve spring(s)

The only thing on the list that sort of sticks out to me is "Fuel contamination"...based on the fact the car was sitting outside for a few months (with between 1/4 and 1/2 tank of gas in it) by the time it was reassembled I wasn't sure how bad the gas was so I put in some fuel additive after it was running rough for a bit on start. It later smoothed out in idle but not sure if all that gas needs to be burned out.

Assuming the gas is not the culprit where would you guys start first? By visual inspection all the wiring and connections look okay. The injectors we put in were re-manufactured and assuming the re-manufacturer tested them... so they should be good(right?) and like Don said is unlikely two misfires on different banks out of nowhere would point to coils failing all of the sudden. How would one even test the injectors considering the supercharger for the XJR is fitted on top of the fuel rails... you cant just start the car and inspect them with engine on like you could with an XJ8 it seems

Any ideas/input greatly appreciated. Looking forward to bringing this beast back to life. Only 49k on her!

 

P1229 Throttle Motor Control Circuit Malfunction sticks out with me.

Quick question. Did you replace the throttle body?

I seem to remember some parts missing on your original when
trying to reassemble.

 

Thanks Jackra_1,

We didn't replace the throttle body but we did misplace that little metal butterfly valve inside the throttle body elbow which is activated by a vacuum. We ended up buying a used throttle body elbow and transferred that piece to ours and it appeared to work as it should.

There must be a way to test the injectors to make sure the remanufactured ones I got are all working properly? After visually inspecting all the connections that seems like the next logical step to me but I don't understand how you can check that they work without having the car running.

Any ideas greatly appreciated. Just don't know where/how to start really. Diagnosing problems has always been my least favorite thing about fixing cars haha

 

I believe you can test the injectors using the WDS, IDS or SDD diagnostic system, it's been a while since I looked but I believe in one of the guided tests, you can activate each injector individually with the engine off, and you have to listen for the "click".

Trying to pin down these problems without a suitable diagnostic system will be a bit tricky in my opinion. Sorry can't help much more than that...

 

"Engines Systems fault,DSC not available, Parking Brake Fault go disappear but always come back on within a couple minute of idling."

You get lots of different warnings and dtc's and you said the car sat outside for months.

What did you do about the battery?

Might be worth having it load tested.

 

Thanks Meirion the battery did die eventually as the car was sitting but we charged it back up and it fired up the engine with no problem but there is definitely a possibility the battery is not 100%. Will have it load tested tomorrow.

 

Check the grounds as well. There's 3 behind the headlights and another in the trunk from battery to body. Sometimes things coincidently fail when we fix other items.
I coincidentally had ignition coils fail on me right at the same time I repaired a leaking transmision pan and refill. The car didn't give any codes and the misfires were causing the transmission to act funny. I thought I had done something wrong to the transmission causing me to redo the whole procedure again. Took me two weeks to finally figure out what was going on.

 

Thanks Blakkat,

Very good idea... will be sure to check the grounds. I think the battery is likely not good as I remember before starting the car I charged it for 48 hours and the charger didn't indicate a full charge when it should have only taken 24 - 36 hours to get it to fully charged. Load test will confirm tomorrow.

But the battery being bad wouldn't cause the injector codes though right? Maybe the Engine systems fault, DSC fault, park brake fault... I just find it unlikely as the injectors were swapped out and now I'm getting misfires on bank 3 & 4 and a circuit open on cylinder 5 (same cylinder I had a misfire on before swapping injectors). Going to peel back the electrical tape on cylinder 5 wires to inspect them closely as the circuit is open as indicated by P0205 Cylinder 5 Injector Circuit / Open. Any other ideas/things to inspect/tests I can do that could point to this code?

Lastly, I know the throttle body and elbow "isn't supposed to be cleaned" yet searching through the forums some people have cleaned it with positive results...my throttle body and the elbow are absolutely filthy (pics attached) would you guys try to clean this one?

 

I would clean it. Mine was a lot worse than yours at about 100,000 miles.

I believe the reason Jaguar say not to clean the TB is because originally it had a coating which was supposed to stop exactly what you are seeing.

 

Thanks Jakra,

I'll just go for it then. Do you have any recommendations on cleaning the TB? I was thinking soft bristle tooth brush then spray throttle body cleaner on a rag then wipe the black crud out?

So I went ahead and load tested battery and it is NO good. Bought a new battery but while I think this could potentially be the cause of the Engine systems, DSC not avail, Parking brake fault messages I can't see the bad battery being the cause of the following 6 codes or am I wrong to assume that?

P0300 Random Misfire Detected
P0303 Cylinder 3 Misfire Detected
P0304 Cylinder 4 Misfire Detected
P1316 Misfire Excessive Emission OR could be Injector Driver Module Codes Detected
P0205 Cylinder 5 Injector Circuit / Open
P1229 Throttle Motor Control Circuit Malfunction


I was talking to my DIY mechanic friend and he thinks that we should be able to do a couple tests...
1. turn the key forward in ignition and probe the electrical wires going to the injectors with a test light to make sure we are getting current to each connector 2. Turn key forward to listen with a metal rod for injectors clicking to make sure the re-manufactured injectors are good. Is my friend mistaken or is this doable on the XJR? I believe the only things that are currently disconnected/would still be disconnected when turning key forward would be the throttle body connectors, egr connector, and coolant temp sensor ...so I should be able to turn key forward and run tests on injectors with those connections unplugged right? I want someone with more experience to let me know for sure as I would hate to make more problems for myself. My friend mainly works on motorcycles, by no means an expert.

 

I used very fine wet and dry sand paper along with TB cleaner. I ended up with an almost "polished" surface in the TB.

For the "nooks and crannys" I did use a bronze wire brush very gently.

The carbon deposit on mine was quite hard.

If it were me in your situation I would focus on the P1229 issue first. IF it is still there after renewing the battery.

I suspect that it plays a role in the misfire etc faults.

 

Hi hawaiianjag,

I've been following your journey and I agree with jackra_1 that of the above codes the one to address first is P1229. However, I have also seen this sort of list of random codes caused by low battery voltage, especially while cranking. Now that you've replaced the battery, are all of these codes still appearing? Have you tried clearing them to see which, if any, recur?

If you used WD40 on the throttle motor connector or the connectors for the coils and injectors, you could be dealing with the added electrical resistance of the oily residue that WD40 leaves behind. I would recommend you go back through and flush all the connectors with zero-residue electrical contact cleaner spray, work the connectors together and apart a few times, reflush, then allow them to dry thoroughly before reconnecting.

Another thought that comes to mind is that even if the battery is new, what matters to the ECM is the voltage it actually receives, which can be reduced by corrosion on the battery power connections and ground points used by the ECM. BlackKat mentioned a few of the grounds earlier, but if I'm not mistaken the primary ground point used by the ECM is on the right inner fender, rearward of the suspension tower, beside or under the cabin air microfilter housing (for LHD cars - it's the opposite side on RHD cars).

Testing for battery power at the coils with the key in Position II is easy, but if I'm not mistaken the injectors are not as easy to access on a supercharged engine. To see which wires should have battery power with the ignition on, consult the relevant figures in the Electrical Guide, which you can download at the link below, courtesy of Gus and his jagrepair.com website:

2004 X350 Electrical Guide

Note that for electrical tests on modern cars you should use a digital multimeter with a high internal resistance and never use a test lamp unless you know exactly what you are doing. Even with the resistance of the bulb a test lamp can draw too much current and fry a sensitive and expensive component like the Engine Control Module.

Cheers,

Don

 

Thanks Jakra and Don,

I haven't put everything back together yet as we have her stripped all the way down to the fuel injectors with supercharger out but I just want to make sure we test what we can while we have all these parts out. Also seems like cleaning the throttle body would be easier to do with the part out. I am waiting for the last few gaskets as well before we put everything back together.

I only used the WD40 on the connector which plugs into the TPS 4 pin on the throttle body as it was mentioned on a Jaguar Forums thread I read one time. Thanks for letting me know that was not the right stuff to use! I purchased electrical connector spray in addition to the throttle body spray last night so I'll be sure to follow the procedure you so kindly provided. Thank you for the tip about not using the test light, we will be sure to use the multimeter.

I just want to make sure that we inspect/test everything we can before reassembling considering the work involved getting it to this point.

Fingers crossed all those codes were because of the battery being bad

 

Failing batteries can cause random codes as has already been said.

I suggest you leave the electrical tests until after you have changed the battery.

 

Thanks everyone for the tips and suggestions throughout this process. Finally my XJR is running without any codes. 2nd reassembly was a success, removed all injectors again, inspected and sprayed electrical connections to injectors and the TPS sensor on the throttle body elbow, then lightly cleaned throttle body and elbow to get the black residue out lastly threw in a fresh battery and started it up... Engine systems fault, DSC not available, park brake fault went away but all the other engine codes remained however the car sounded like it was running great. Finally did a hard reset holding both pos. and neg. cables to the battery together for 30 min. Reconnected battery, started her again and no fault messages or codes now. Hallelujah!

Last thing to mention is that I was also getting a scrolling screen when I bought the car from the original owner. Thought it might be a connection issue going into the head unit. After changing the battery I noticed the screen would stay stationary/normal for a bit then would start rolling/pulsing again but on the last couple drives with the fresh battery and the car has stopped scrolling...fingers crossed this problem is behind me as well and it was just scrolling from a bad battery.

A big thanks to all of you who consistently help me and countless others with our Jaguar problems. If any of you find your way over to Oahu, Hawaii the drinks are on me, just shoot me a PM. I can also set you up with a place to stay, manage many vacation rentals and will give you the family rate. Mahalo nui loa