Try starting on N.

 

More than likely your brake light switch has gone bad. The brake switch is what activates the Park release solenoid. You can remove the small star looking plug on the upper left corner of the shift console to manually release the solenoid. The ignition key will unscrew the plug and then you can insert the key to release the solenoid and shift to neutral.

 

 

Hallo Jeroen,

Wat je ook nog kan doen indien je allerlei rare meldingen op je dashoard vindt, probeer een "hard reset".

Contact uit.
Maak de neg kabel (strang)l van de batterij los en raak er de positive pool mee aan gedurende twintig seconden. (Wat je daarmee doet is condensatoren ontladen in het computer systeem).
Verbind de strang terug.
Probeer te starten en te rijden.

Baat het niet, het schaadt ook niet.

Ps: NEG aan PLUS, niet omgekeerd of je maakt een kortsluiting.

Groet,

Takeo.

 

The Google translation of that is................................................ ..............

Hi Jeroen,

Whatever you can do if you find all sorts of strange reports on your dashboard, try a "hard reset".
Disconnect the negative cable (string) 1 from the battery and touch the positive pole for twenty seconds. (What you do is discharge capacitors in the computer system).
Re-connect the string.
Try to start and drive.

Do not get it, it does not hurt either.

Ps: NEG to PLUS, not reverse or short circuit.



.

 

Resetting the DTCs is not going to make the fault disappear. Have a Jaguar specialist read the DTC(s) stored in the system to determine the cause of the restricted performance.

Another item is to check the battery as a failing or weak battery can cause mysterious electrical faults to appear. Battery should have a minimum of 12.6 volts across the terminals with the ignition in the OFF position for ten minutes or more. If there are less than 12.6 volts, disconnect the battery from the car and charge it overnight then retest. If still less than 12.6 volts, the battery should be replaced.

Have you checked the earthing points for corrosion?

 

Thanks all for your suggestions. My problem is I am in Germany trying to enjoy the Classic Grand Prix. I would prefer not to have to spend my time here to find a Jaguar Dealer.

Anyway, as I said earlier, the problem seems to be gone. I drove well over 160 km today. Not a problem. On these old(er) cars my experience is that resetting the DTCs might get you many thousands of miles trouble free driving again. Some of this stuff is getting on a bit, which can cause some spurious problems. The system is supposed to have thresholds for that, but after a while you might still get some problems. Also, back home I have an Autoengenuity and a Autel code reader that are perfectly capable of pulling any and all, including Jaguar specific DTCs from this car. I hate to have to pay Jaguar to tell me that the code are gone, or they still can’t find the problem, which is usually the case with spurious faults.

I am almost religious about keeping the battery and earth points clean and healthy. Battery is only 18 months old, and is kept on a very sophisticated trickle charge when back home in my garage. Every other year I undo all earthing points, clean them etc. I did check the voltages yesterday, but all is perfect.

I did have another problem this morning. The right front and rear door wouldn’t open with the remote. When using the button on the dashboard, the front did open but not the rear. Just pulled the little pin up and down a couple of times and that is working as well.

I will be here for two more days with at least 60-70km driving tomorrow and about 350 on Sunday. Let us see what happens.

I still would like to understand what formal conditions can trigger the “electrical fault” on the dashboard. Because it will/might gave me an idea what to check if it happens again.

Jeroen
(Really enjoying the Classic Grand Prix at the Nurburg ring)

 

The codes would not be gone (if you stopped erasing them) as they're kept a long time (40 or 80 warm ups) even if the MIL is back off.

You're a bit stuck given your wishes right now but plan on proper fault fixing ASAP.

 

Well, I got home alright. In all did about 600-700 km after these problems popped up.

As soon as I got home I put my Autel OBD scanner on the car, but no DTCs. Nothing pending, nothing stored. I checked my log (I keep track of everything that happens to this car). I had a restricted performance about 24 months / 18.000 km ago. Re-setted it then under similar conditions as this one (far away from home).
But as far as I can trace I have never seen this “Electrical Fault” on the display yet. So I have been checking a lot of technical documentation, JTIS and various other bits of paper I have picked up over the years.

Cant find a thing. Remarkably it is not even mentioned in some of the Owner Manuals I went through.
So the search to find the trigger for an “electrical fault” on the dashboard is on, because that might at least give me a few pointers what to expect.

But at the same time, it might be as a I said earlier. On these older cars the electronics might trow the odd wobble and you will never be able to find anything.

If it takes another 24 months / 18.000 km I’m good.

Jeroen

Jeroen

 

You said you cleared the codes so that's why there are none. But what were they before you cleared them?

The park thing is one of the interlocks and there are plenty of threads about them to help you.

 

Thanks. I don’t know what the codes were. Like I said I have a simple generic OBD scanner in the car, but it told me they were Jaguar codes and it could not read them. So I just cleared the whole lot. At least that is what got me going again. Sometimes after clearing you might still find the odd pending or saved code. No such luck this time.

I have found a few hidden threads on this forum regarding the electrical fault on the display that point towards the BCM. If anything that also controls the locking/unlocking of the right hand doors that were a problem too. To me it seems one of these cases where maybe it got a bit of a Voltage dip for whatever reason and it went haywire for a minute, resetting clears everything and restores normality. So I will be doing some wire, fuses and more earth point checks on this one, just te be sure.

On my next trip I will bring my Autel OBD scanner as it will read the Jaguar codes and at least it might give my something to work on.

Jeroen

 

The only thing that I've experienced that popped up a lot of very alarming messages was quite recently when I plugged in a vgate SUPER ScanTool VS600. I've decided to never use it again in the jag after the shock of so many error messages. I actually thought that I'd fried the main ecu. Thankfully doing the hard reset disconnection of the battery seems to have cleared it though.
Sends shivers down my spine even now!

 

I know the feeling. We had a go at my eldest son VW Golf GTI the other day. HIs speedo wasn’t working. Pulled fourteen DTCs!!
Just resented them all and all, but one, have stayed away since.

Like I said, I believe on these older cars (The GTI is even older than my XJR) you will see spurious alarms. If anything is really amiss, the code want clear/reset, or pop up straight away again. Anything else is just annoying, but of no immediate concern as far as I am concerned.

Jeroen

 

So I drove almost 1500km with no problems after the last electronic escapade in Germany.

Just for good measure I had put my fancy Autel in the boot. Just in case it would happen again.

Sure enough, last Sunday I was on my way to a Jaguar event, again in Germany as it so happens. About twenty minutes into my drive the engine goes into failsafe. Also on the dash neither Trac or ASC available. So I coasted over to the slip road, hooked up my OBD reader and sure enough P1121. Re-setted it and drove on. Ten minutes later it happened again. Both times it happened as I was on cruise control and I touched the brake. I tried to repeat it, but no matter how hard I tried it never happened again. I have replaced the infamous brake switch some 8 years ago. That time I recall I also had a specific code pertaining to the brake switch. This time only P1121.

Managed to reach the venue and drive back again, in all some 300km with no further problems.

My Jaguar had its throttle body replaced, courtesy of Jaguar in 2010 or thereabouts. Since I have driven about 55000 miles. I would hope the potentiometers would last at least that long. So at least for now I am proceeding on the basis of it not being a problem with the potentiometer. (I know this might prove to be wishful thinking of course)

So here is what I have done so far:
Read up a lot of post containing P1121 on the forum (and I mean a lot!)
Disconnect all three connectors on the throttle body. Inspected them, cleaned them. Could not spot anything on them, no corrosion, no mechanical damage on the pins. One retaining clip on one of the connectors was broken (or maybe I broke it trying to dislodge the connector). But the connector looked as if it fitted snugly and firmly
As I had to undo the air mass meter, checked, cleaned those connectors too
Took all connectors of the ECU, checked and cleaned them, nothing appears amiss
Opened up the ECU and did a very thorough visual inspection on the PCB for cracks or loose components. Nothing found
Undid the fat earthing cable just in front of the ECU. Minute corrosion, cleaned it.

I also checked my JTIS and it list various possible causes. I would like some advice on how to verify / test these

; Accelerator pedal to pedal postion sensor cable adjustment incorrectly
How do I check this. The cable does have a bit of slack. never noticed it driving, but you need to push the pedal in a bit before it will actually start rotating the butterfly valve

: Pedal postion sensor to ECM sense circuit 1 and 2 open circuit, short circuit or high resistance.
Other than the visual inspection of the connectors as described above, any suggestions what else?

: Sensor power supply fault
; Pedal position sensor failure
That would be the dreaded potentiometer. I have read somewhere that you might be able to verify the proper function through a live function on an OBD reader. I need to find out if I can do this on mine. I might have to get my old Engenuity scanner going again!

; sensor reference ground fault
When checking the wiring diagram it looks all the sensors are grounded via the ECU. Is there some common ground/earth pertaining to these circuits I should be checking as well.

The problem is of course that this is still an intermittent problem, so difficult to find. Any suggestion on what other actions/test I could try would be highly appreciated.

Jeroen

 

Typical German advice to this problem would be : Time to get a brand new car- don't waste your time with anything older than 8 years ;-)

One reason why I left..

Anyway, Im having issues with my car and the PATS or passive anti theft system.
It happens now and then and isn't consistent but it doesn't go into limp home mode.

I need to check the wiring to the inertia switch, the connections to the security module in the boot and other stuff.

Amongst the codes I got first time around I got P1260

Second time (yesterday)

I got

U1135
P0100
P20e2
P1632
C1145

I fear a lot of these, however' are the symptoms rather than the disease itself.

 

Jeroen - to check your pedal position and it's range in percentage - plug an OBD reader in and navigate to throttle position.

Next very slowly press the accelerator pedal and watch at the reading climbs, if at any point you loose the reading - ie drops 0% or fluctuation then the PPS tracks are toast.

To reset the throttle so as to get as near to 100% you'll need to cut off the zip tie holding the adjustment 'square' that snugs into the throttle cable bracket on the TB - and by turning either way you tighten or loosen the throttle cable and pedal - set it at 95% + but don't try for 100% because it defaults into failsafe mode.

The TPS can be replaced, but the TPPS cannot. If this is causing the failsafe mode then a replacement throttle body or rebuild is in order. To confirm this it's a case of the 1121 reappearing, and it usually becomes more and more common.

 

Just to prevent mistakes here, above is is not completely accurate.

You will need to adjust the mentioned "square" first, but you will need to keep some slack there!
Procedure is to tighten up till you see your OBD reader start just moving (from ~2.5% at idle with cold engine), then turn back 1/4 or 1/2 turn.
After that, the 90% (according Jaguar) or 95% (according Sean) are set with the bump stop or kick down switch, located under the accelerator pedal in the foot well.

Good luck solving your problem with help of these great members, I (un)fortunately can't add much useful info to your problem.

 

Thanks everybody. Last night I had a go with my OBD reader live function at looking at the readings. Went up and down a couple of times with no fluctuation whatsoever. I will take the car for a test drive today. See how it goes.

I haven’t checked the accelerator cable yet, but the way I read it, you want a bit of slack anyway. too little slack might cause a failsafe, too tight might mean your pedal doesn’t hit the kick down switch. Mine has some slack and the kick down works.
Jeroen

 

I have driven the car now for some 500 miles with no problems. So it looks as if all the fiddling/cleaning has solved the problem for now.

I have also been looking into getting the throttle body replaced. Found several options. Replacing it with a second hand doesn’t sound to appealing to me. You never know how long it will last.

Here in the Netherlands I have found a few specialists who claim to replace it with a new one for around Euro 1000,--. I suspect though they are using reconditioned ones.

As I mentioned earlier, my throttle body was replaced in the USA shortly after buying the car in 2009/2010. Courtesy Jaguar at the time. I still have that throttle body. I have been talking to ASI as I have read good reviews on their reconditioning/overhaul service. So I have decided to send my old throttle body across the pond to get services. About $450 plus postage will cost me around Euro 530 or thereabouts. But then I have a my own spare (good as new I hope) throttle body to go if these problems arise again.

I need to check what other parts I will need as I might as well get them as well. As far as I can tell just the gasket.
Is there anything that needs adjusting if you swap the throttle body? Or is it literally plug and play and the ECU will figure it all out?

So of the post office with a package going to the USA.

Jeroen