update, I have noticed the kicking, spluttering/ missing call it what you like, cutting out seems to be mainly at high to full throttle, she will cruise around up to 3000 and just occasionally miss but more times than not at full throttle it really gets upset till I back off.
I get a code for lean mixture bank 1, it feels like she is starved of fuel high end or ign coil breaking down but then it has six and I just replaced those and the plugs, there are no air leaks and I just replaced the fuel filter which was dirty but not heavily.
the front o2 sensor had a broken wire so I connected with a scotch lock as it says absolutely do not solder wires, I am going to replace it just in case the scotch lock is causing high resistance or something affecting its ability to accurately measure.
I have checked all electrical connections in engine bay, no corrosion and all looks good, I am suspecting the TPS although throttle opens fully if this is failing it will not be telling the ecu to pump more fuel, going to find how to test it.
again all this is intermittent some days she drives and behaves perfectly right through rev range no problem then all of the sudden she kicks off again, really annoying, not that I am a rev head generally don't go much above 3000 but when I need to I also need to know its there.
Fan issue has not changed

 

Replaced O2 sensor under air filter, I took the car for a run got it to temp, ECL came on, I checked codes P1647 o2 sensor, I cleared the codes left it for an hour went for another drive and no issue no ECL and no codes recorded emission codes at least.
I ran until up to temp then put her through paces a little, got to almost 6000rpm and back down several times she performed like a new one, no lights no missing just the pleasure I used to have, we will see if any issues return.
side note cooling fans still running full with ign on and stop a few moments after ign off.

 

Wayne I may be able to help. Have you checked the fans themselves. I had the same issue with the drag/lurching at highway speeds. My AC fan was shot. Was sticky and wobbly. All I did to check was to reach in when nothing was running and spun them (or tried to). I replaced the fans from Rock Auto at about $200 and the lurching has decreased considerably. It is still there a small bit when the AC fan kicks on, but very minor compared to before. I'm guessing amp draw from that fan was causing the engine lag. I also had very loud vibrating fans, fixed that too. Later.

 

Hi Jason,
Thanks for the input, fans are not the problem here, if you read back in the thread one day the fans kicked in and would not power down even long after the engine was cold unless disconnected, I replaced the module and now they start when I turn ign on and stop moments after I remove key but are on full speed constantly from cold start to stop.
I also get a mixture weak code for bank 1 but I think this may be the front o2 sensor I replaced with after market also car runs rough for first minute or so from cold start, I have replaced plugs and full set coil packs checked for leaks none found.
I am living with it till I get a moment to get involved again with fresh eyes to find and fix issues apart from this she drives great.

 

That is quite strange. I've never had a car do that before. Hope you get it figured out.

 

Hi Jason,
Thanks for the input, fans are not the problem here, if you read back in the thread one day the fans kicked in and would not power down even long after the engine was cold unless disconnected, I replaced the module and now they start when I turn ign on and stop moments after I remove key but are on full speed constantly from cold start to stop.
I also get a mixture weak code for bank 1 but I think this may be the front o2 sensor I replaced with after market also car runs rough for first minute or so from cold start, I have replaced plugs and full set coil packs checked for leaks none found.
I am living with it till I get a moment to get involved again with fresh eyes to find and fix issues apart from this she drives great.

 

Hi Wayne,


I am experiencing the same issues(s) here. Fan wouldn't turn off even with ignition off, so I replaced the module. Now it stays on when ignition is on and a few moments after when car is turned off.


I bought a "New" fan control module form China but now I'm thinking it's faulty, so I'll look for another one and update.


I'm also getting misfires and a P0171 occasionally. I don't believe they are related but if you have any updates on either issue, please share. Thanks,


-Greg

 

Hi Greg,
Thanks for the post, I bought two modules from china supplier both do the same thing as yours, come on with ign & stop running a few seconds after ign off. I too think they might be faulty and you having the same issue might confirm this, I am looking for a wrecked X-type to get test parts if they fix the problem I will happily pay the wrecker.
as to the codes it tells me lean mixture bank 1, I have replaced the O2 sensor under the air filter box (non genuine) cleared codes but it returns, it does feel like a misfire on cold start and takes a minute to steady but now does not run bad.
I have also replaced S/plugs and full set of ign coils since the back ones are a pain having to remove intake manifold, I have not replaced all the big O rings seals top and bottom of manifold I did add blue gasket maker to the top ones not that it made any difference.
once together I replaced fuel filter some hoses, coolant for water-less and ran engine to temp then used an old trick got a can of "start ya bast**d" and sprayed everywhere around any form of air intake to see if the engine made a response of surging or dying or spluttering, I had absolutely zero difference in running RPM which to an old mech like me says there is no intake air leaks and therefore should not have this issue.
I am contemplating replacing all intake O rings and having injectors serviced whilst apart just so I eliminate future possible from equation, she actually runs well for 157,000k and for what she cost I am reluctant to throw too much into her.
let me know how you go interested to see if anyone has fixes

 

The control system for the fans is a bit complex! Easiest explanation is to quote JTIS:

Two variable speed electric cooling fansare housed in the cooling fan shroud for the cooling of the radiator. The speed of the electric cooling fans is adjusted by thecooling fan control module, which is controlled by the engine control module (ECM).The ECM determines the coolingfan speed by receiving inputs from thecylinder head temperature (CHT) sensor. The ECM sends a variable pulse width modulated (PWM) signal to the coolingfan control module to operate the cooling fans at the required speed. The cooling fans are operated at slow speed when theengine coolant temperature is at 95°C (203°F) and are operated at full speed when the engine coolant temperature is at 105°C (221°F). A coolant temperature between these temperatures will cause the cooling fans to be operated at a speed which is proportional to the engine coolanttemperature.When the engine is running with the CHT above 100°C (212°F), if theignition switch is turned to the OFF position the cooling fans will continue to operate for a time which is determined by the ECM.If the PWM signal from the ECM to the cooling fan control module is between 7% and 95% the cooling fancontrol module will operate the cooling fans at the required speed. If the PWM signal from the ECM to the cooling fan control module is below 3% and above 95% the cooling fan control module will operate the cooling fans at maximum speed. If the PWM signal from the ECM to the cooling fan control module is between 3% and 7% the cooling fans will not operate.

 

So now that being said, as I researched my question. My fans come on at full speed w/AC as they should. But, when I turn the car off they go completely off. No run down as many of my cars have done.

So would this be an indication of a faulty fan control module?

 

I would like to get my hands on a known good module to try on my car to eliminate from investigation but can't find one I know to be working correctly, as I say the two I got from china have the same action which is on full whenever ign is on regardless of temp of engine.
The original one I replaced just started one day and refused to stop until battery was flat or I disconnected it, (I have thrown it out unfortunately)
I was also having issue missing when cold for first couple of minutes and lean mixture code I was sure there were no leaks on intake or ancilliaries but I kep coming back to someones comment "it is definately an air leak" when responding to others with same code so I decided pull it apart including all intake manifolds, I could'nt pin point a area but the lower intake manifold seals did look a little suspect (squished/compressed unevenly) so not having first ordered a bunch of expensive manifold seals upper and lower I resorted to gasket maker silicone, I cleaned out all the housings, applied balck silicone refitted seals and reassembled checking all other possible sources as I went, once together I left it overnight for the silicone to fully cure then cleared codes and started engine, it was immediately improved no missing spluttering or codes, it ran smooth and as it should from cold, a road test confirmed it was running miles smoother but did throw up a ecl code but this time not for lean mixture but just the O2 sensor I had already repalced with cheap generic ebay one ( I have ordered right one) I stopped cleared codes again and it drive for about 2klm before same P1647 lit up ecl again.
So even when I as a retired mechanic after testing for leaks with vac gauge and spraying all components with high octane did not get any of the tell tell signs of an air leak did actually have one on the lower intake seals (somewhere) I am glad to have fixed it for a couple of bucks worth of gasket silicone and not spend $150+ on seals, time will tell if it stays sealed but for now I am one step closer to getting her running how she was when I bought her.

 

Hi Chris,
I have again tested the voltages, at cold I get 0.02, warming it goes to 1.25 and when normal with thermostat open gauge normal middle all climate off I get 1.06v so I believe as you say it is the module so don't buy from china I guess is the moral, I am yet to find a known working one to test theory, don't want to buy unknown from E-Bay

I did strip down and find possible air leak at manifold seals lower so I fixed that and after putting back together it runs much smoother, missing at cold gone idle solid, I am getting P1647 forward o2 sensor, again I got from Ebay but have now ordered correct one will post results as and when I get and test parts and theories.
thanks for all the help and input from other guys also it is much appreciated.

 

Has anyone tried replacing/diagnosing the CHS (cylinder head temperature sensor) and circuit? Apparently this is the sensor that tells the computer to turn the fan on/off.

Might me worth checking its location and replacement procedure!

 

Hi guys,
ok here is my latest update, I don't know how or why but the fans running full speed all the time ign was ON has stopped ? I went out the other day key into ign no sound of fans started car and drove weird but no roar from fans, I stopped opened the bonnet thinking something else had gone wrong but the fan was behaving exactly as it should (with A/C off) I could not understand but was happy.
now is about five days later been out every day and problem has not returned, fans are working correctly temp normal no problem, I waited for today before posting as the o2 sensor arrived, I fitted it, cleared codes and went for a drive from cold and presto everything in the garden is rosey no ecl no loud fans engine is smooth all is as it was when I bought it.
now I have probably jinxed myself or the car but everything crossed looks like my Jaguar woes are over at least for now so I am just going to enjoy it, hope everyone else finds their fixes and thanks for all the help guys.

 

I bought two of these fan modules from China (just in case) as it turns out I didn't need a second so if anyone has confirmed they need one I can let then have this second one for $55 +P+P
I probably replaced my original prematurely since the issue has resolved itself but anyway with this new module the fans behave perfectly as they should.
I will update if sold prior, cheers

 

If it is the cooling fan control module X400, the old original one, the capacitors are probably shot. I opened the module, change the capacitors and transistors and the thing works normally. You can see what I did if you search for "fix Jaguar X400 control module" on the web. There is a short version with no sound and long version with sound. They both have lots of pictures and text.

 

Hi X-Type, thanks for the post, my module is different, but I tossed the original anyway when the two replacements arrived from China, I know rooky mistake anyway the problem is intermittent.

after fixing manifold air leaks and forward O2 sensor I got to a point where the only issue was fans running, I have been in contact with turbo (Chris) previously and carried out tests as per his instruction cheers Chris, I did replace the module with new one from China, my original issue was one day after a drive both fans were running full and flattening battery with or without engine running hot or cold ign or not, replaced module fans then ran when ign turned on and went off after key removed for few seconds, I could live with that, then everything started working properly on some days fans would only come on when temp demanded them or A/C turned on but then would revert to being on all time with ign on.
yesterday the temp gauge which has never gone above mid-range suddenly went to almost red, I pulled over killed engine and left ign on, no fans operating hoses fit to burst with pressure, I had no tools so had to wait to cool down, my theory I would get home (not far) in leaps and stop to cool when needed but when I pulled away the temp went back to normal and I could hear the fans running so carried on to get home.
today I checked connections, battery and earths etc. no codes no leaks, no coolant loss, belts all good everything looked ok so I left ODBC on to keep track of temp and started car, let it run to temp, gauge rose gradually to normal but ODBCII saw temp continue to rise to 106degrees and no fans cut in not even when I turned on A/C so I turned off engine to cool, when I can get my big hands near enough I will check values again but all these problems seem to me like electrical gremlins very hit and miss and intermittent and a real headache.
I don't want to start using bodges to install additional manually controlled fans to reduce temp I would rather have her work the way she is meant too.
as usual guys any help appreciated.
OK she has cooled enough to work on, I checked the blue/white wire and getting 0.12v not exactly cold engine yet though so I replaced the module with second one I bought at same time from China (no disrespect but they were cheap so got two) volts still 0.10v and now am back to where I started? almost, fans coming on full with ign, speed reduces when A/C turned on, I can at least now run her again and see if things settle or go wrong over next few days.
I hate electrical gremlins so now Iam wondering why I put a deposit on a new tesla model 3 lol
A few days later fans still start full with ign (happy to put up with that) after a drive noticed they werent running, temp started to climb again, (luckily I changed to Evans waterless the ODBC said temp was approaching 115 degrees so I killed the engine to allow to cool.
so this clears the fan module so now I am still thinking gremlin (poor electrical connection somewhere) I am suspecting the ECU has intermittent issues maybe, so guys, where is it can I test it or any ideas on price of replacement,

yesterday I was doing the wire wiggle testing method where I try to see if I can make the problem go away or repeat with moving engine bay harness around (sometimes this will show poor connections) in this case it did nothing, I started the car from cold after ODBC code clearing not that there were any.
engine started normally, no fans running, after a few minutes fan kicked in for about 5 seconds then off and it did this regularly as it should to mentain temp, after about 15 minutes idling the fans stopped cutting in and the temp began to rise over 100 degrees again getting to 115 before I shut her down, I was tryint to remove the harness from ECU near bulkhead to check for water ingress, corrosion etc but it has tamperproof screw which I need to get around.
the way it stands is this is very hit and misss it could be temp related as in when the car get to temp an electrical contact has expanded to a point it becomes unreliable and the problem I am having starts again.
thinking of getting a mobile sparks in to test it but if anyone has experienced similar gremlins please let me know.