Still stumped with this one. Going through the pin-point tests in the '99 version of the workshop manual, it asks to check that the KTM is getting an ignition-switched-negative signal on pin 13 of the connector (FC22) - a white/red wire.

This is failing for me, the resistance is huge. I can't find all of the KTM's wiring in the diagrams. Anyone know what pin 13 connects to ? Or what sits in between the ignition switch and the KTM for the switched-negative ? Wiring diagram doesn't show all of the pins for the KTM.

I checked the battery connections, high-power fuses, and all fuses and relays - all good. Ignition switch is fine, it's doing what it should do with no resistance. Transponder coil around the ignition key is fine, good 3 Ohm resistance.

To confirm, all other circuits, lights, gadgets, switches on the car work fine. The engine cranks but does not catch. Fuel pump is not energising because of the KTM not seeing a switched-negative on FC22-13. I think this U1135 is where it's at.

 

Hi,
With the caveat that this is for a 98, I've attached the relevant snippets of the missing 13.2/3 diagram and the pinout list.

Pin 13 routes back through to the ignition switch position i (aux), and should ground when the key is in that position: see Fig. 2.1 in the 97 JTIS. Note that the relevant octagon connection symbol there contains 16 rather than the 15 shown on the snippet.

Double-check the wire colour on FC22 pin 13 - the 97 & 99 JTIS and the snippet all show a white/brown wire routing to that connection?

Mike

 

Sorry I overlooked your first page!

How about telling us what the car is and is not doing.

Have you checked your exciter ring? This is about a $30.00 part that could fix your problem. It is located at the ignition switch and it has 2 wires. Ohm it and it should read 33.4.

 

Thanks MichaelH ! I will seek out a later wiring diagram and make use of it. The later cars have more plugs/wires on the BPM and ECM but the wire colours are the same between the versions - especially for items like the KTM which seem to have stayed the same.

Gus, yeah I pulled out the exciter ring and it's fine, gives a good 33.4 Ohms. The basics of it are that the engine cranks/turns on the starter, but isn't getting fuel. "ENGINE FAULT" is shown on the display. Everything else works fine, including the locking and alarm system. Battery is good and healthy. Brake switch is fine, transmission lever unlocks just fine, no errors there. Fuel pump relay is getting good power but no negative signal from the ECM. Jumping the fuel pump energises it but the car still fails to start. KTM is getting good power but fails test J3 from the instructions (resistance to switch earth is too much). Ignition switch is absolutely fine, everything electrical works fine and the switched grounds are fine at that point.

BPM is giving lots of (seemingly fake) error messages, attached above, for gadgets that are not problematic (like the wipers, seats, mirrors). But the BPM and the SLM are showing U1135 (invalid or missing data for ignition switch/starter).


I am going to make use of MichaelH's diagrams (and search out the 98-onwards diagrams myself) to see what's blocking that switch negative, in case it's coming from the ECM or somewhere else.

 

Your fuel pump has 2 sets of fuses see the attached for the pump power.

Link JagRepair.com - Jaguar Repair Information Resource

I would think that if the security module were an issue the car would not turn over but not 100% sure.

Do you have another key to try?

With no security light blinking I would think you are not locked out so I would not be looking in that direction yet. The fact that you tested voltage to the pump tells me the security system is not blocking it from working.

I would be focused on the crank sensor. It is mounted behind the flywheel. I am not sure it will throw a code on start.

Check and see if the lights on the sunvisor mirrors are working. This fuse will prevent the car from starting. It is located in the driver’s fuse box in the door jam.

You need 3 things for the car to start fuel, spark and compression. You say you have fuel (still check the other fuse) spark is questionable. The 97 AJ26 has 2 ignition modules you need to check the fuses to the both of them.

Your U1135 is directing me to the driver’s door and seat module to my knowledge they have nothing to do with starting the car. With no other codes I would clear it as suggested and do a hard reset and start from the beginning.

1997 Wiring diagram http://jagrepair.com/images/AutoRepa.../jagxk1997.pdf

Just my .02

 

Happy New Year everyone

Sorry to say, replacing the crank position sensor did not solve it. Resetting everything, the ENGINE FAULT message does not appear until you turn the starter, then it's on within a second of the starter turning.

I have been around all of the fuses, they are fine; relays have been swapped around as much as possible; battery is full; locks and alarm are working as expected, including the red LED lighting/extinguishing when it should. Using the second/spare key, same result.

Fuel pump relay is getting power, just not the negative "go" signal from the ECM, etc.

I am going to go through the "305-55 Hard Start.pdf" troubleshooting doc, it has more info for the ECM pinouts and tests.

 

If you have spark and you have fuel I would be looking at cylinder washing providing no compression. One of the characteristics of cylinder washing is that the engine when starting will spin more freely without the lull of true compression. You could also check it by performing a simple compression test using a compression testing gauge. It would be smart to get the basic tests done before digging into it when it may not be necessary. Do not get distracted and document your testing.

 

your getting lots of help from people way more knowledgeable than me but still sounds like a security issue, engine turns over but no fuel from pump. I recently had a key programed by jag dealer but prior to getting it done key just turned over engine but wouldn't start, sorry don't remember if it displayed a warning as I knew it would not start but just wanted to see what would happen, anyway my point being, and maybe someone else knows, is it possible that the program code in the car has changed or is corrupt and will not recognize either of the keys anymore?

 

I guess it is entirely possible but need to make several important checks first and that is to see if you have spark and fuel. I asked if the sunvisor lights were working. The fuse for those lights if blown will prevent the car from starting. The other is that the fuel pump has two sources of power one when the key is turned on and the other when the car is running.

The security system and shifter position are two additional causes along with the ECM. Must start with the basics and work your way through the problem. The big problem is trouble shooting a car you do not have the history on and you do not have your hands on it.

 

Everything you guys are saying is useful, believe me.

I think my check of the fuel pump may have been a misnomer, because doesn't the pump only run briefly at power-up ? So when I have been testing it, it has been non-powered and that's by design (since the engine isn't turning) ?

I switched focus to the coils, they are not getting 12V (purple-white wire). The two ignition modules are supposed to be fed 12V (purple-white wire) via the ignition relay from fuse 18. That fuse is getting 12V but the relay isn't energising. That relay does get 12V from fuse 14, but is failing to get a negative signal from the ECM on pin E13-22 (blue-black wire). Ignition modules have good earth.

Does that sound like an ECM problem ?

So I unplugged the AFM and confirmed that there are two P codes that pop up for that. And then they go away when the AFM is plugged back in. So that means the ECM is working, doesn't it ? Or would it be possible for the ECM to fail some things (like driving the ignition module) but work for other things (like driving the AFM ) ? There are no other P codes. In my mind, if both ign modules are not powering and the relay and fuses are okay, then it's back to the ECM. Also, should there not by this stage be a P1000 code since there was a hard reset, the car needing a comprehensive drive cycle to relearn everything ?

Just to confirm
- there is fuel in the rail
- compression in the cylinders is good
- every single fuse is good
- power to the relevant relays (fuel and ignition) is good
- security LED goes on and off as expected
- spark plugs are new
- battery is perfectly good and is full
- engine cranks but there is no combustion
- no smell of petrol or sign of white smoke (which you would expect given the oil in the cylinders from the compression tests)

Attached are the current codes for the car and the diagram I am working off.

 

Another possible avenue of investigation is the instrument cluster. My understanding is that the early cars had soldering issues (There are many TSBs) and can be repaired. The instrument cluster board is where the various data bus technologies physically meet, so a failed board causes communication errors.

Not sure where we left off with the key transponder module. If you replaced it with another one, there is still a scenario where it will not start as the secret key likely resides in it, so software programming would likely be required. Hopefully another code would pop up as the communication with the KTM would now work, but the key would now not be matched any more.

Best of luck, keep us posted.

 

Interesting, I took the instrument cluster out but didn't think to look inside it.

I did try another KTM, but even after coding in the two keys for the car, the car wouldn't even crank (so either security wasn't happy or the new KTM is not compatible, it came off a later XK8). Just like you say, it probably needed coded. Ignition exciter-ring was fine. Still, there are a couple of security-related codes showing in the list. Just no P-codes (which sent my brain in the ECM direction).

I'll read up on instrument clusters, thanks for the hint

 

How late? I believe the tech changed for the 2000 MY...

 

The US version 97 suffers from leaking capacitors in the ECM, ignition power failure being a common symptom. But the US cars did not have a chip in the key.

 

The spare KTM I bought came off an '01 car. Maybe it's not compatible, but it only cost £15 so no biggie.

I will pull the instrument panel later tonight and do some checks for broken solder, tracks, etc.

Just to recap on one thing I attached very early on - the car shows lots of errors coming from the BPM. I thought these were fake since the items listed are working perfectly.

Does the BPM have any effect on starting ?

Also, the U1041 and U2012 that the BPM is complaining about, would that be comms relating to instrument cluster ? Or should I expect to see some codes that actually mention instrument cluster, if the IC was problematic.

BTW attached is a pic of the ECM - I was hoping to see some weeping capacitors there, but it visually looks okay. Haven't looked at the BPM at all. So next stop is the instrument cluster.

 

That new KTM would very likely not work. If you check the online locksmiths, the key transponder changed for the 2000 MY. The earlier keys have the Megamos 13, the later cars have the Megamos 48. I would still pursue the KTM route, and find a module off of a '97 first. If you locate a '98 or '99, there is also an off chance the ECU will not like it because it is considered "too new" ( the whole VCATS discussion, "incorrect part fitted"). My understanding is that the ECU can be made to accept it with factory-type software.

Have you possibly opened the old KTM? Or checked the wiring from the old KTM to the BPM? Could be as simple as a pinched wire somewhere...

I am still going back to that message about the BPM unable to reach the KTM...

 

My original KTM is LJA2665BB, dated 97/01.
The replacement I got was LNF2665AA, dated 01/12.
Pinouts are the same, and it was confirmed that the replacement came from a later XK8.

I can't find an LJA2665BB for sale, but lots of LNC2665AA (which appear to come from the X308 XJ8). Importantly, the date on these is 97 or 98, which sounds alright.

I might take a punt on one of those given what we're discussing here. And I do get what you are saying, that U2012 message is all about messages from the KTM.

 

I am going to take a shot in the dark, but it will be easy enough to check, given that you have taken some or all of the instrument panel apart.

Check the plug that goes into the back of the fuse panel on the driver's side. In my experience, if that plug isn't pressed in tightly (or disconnected), it will show up as an engine fault on the dash. If the instrument panel is apart, you should be able to reach in and see if it is secure.

Edit: Or maybe the passenger side...I just noticed you have a right hand drive car. At any rate, have a look at the fuse box plug(s).

 

May be a shot in the darkest dark:

Imho there`s a problem with the BPM, a lot of failures:
Communication Bus Error!!!! (no communication with SLM and so Missing Data for Ignition Switch / Starter) , Ignition Key-In-Circuit Failure, so car couldn`t start.

 

I will pull the BPM and have look for anything obvious, and will check its earth etc.
I can see the errors for the BPM but I didn't think the BPM would prevent fuel/spark. According to the advanced electrical guide, the BPM would prevent cranking from happening - but that's not the case for my car, it cranks fine, it just doesn't get fuel/spark.

But I will pull the BPM out to take a look.

http://www.jagrepair.com/images/Trai...s/680_1998.pdf