Hi again,

Yesterday, my beauty was running like a clock until I called in somewhere for a brief 5 minutes on the way home. On returning to the car it won't start. As you turn the ignition all the lights come on and it sounds like the fuel pump kicks in, but not a click from the starter or anything.
Now before everyone jumps at battery, trust me in that this is a one year old 100Ah Bosch battery in excellent condition (sitting at 14.4V currently) I am an electronics engineer and this battery is fine. ECU's and connections may well be a problem - now monsoon season has returned here in the UK...

Anyway, I disconnected said battery and left it 10 minutes, re-connected it and she started instantly as usual. However, it now idles oddly. When revved, it fails to drop quickly back to idle rpm, but sits about 11 to 1300 RPM for a while. I have a log from my OBD2 reader showing mass air flow going from 8 at 794RPM idle to 18 at 1457 RPM but that all sounds reasonable to me. Throttle position reported occasionally 0% (which seemed odd) when before I have seen it at 2 or 3% when idling. I am using the app 'Torque' on my mobile phone via Bluetooth (a great solution)

I turned the engine off, and back on - won't start again, same full set of lights. No engine fault or other light, and no starter click.

Again left for 10 minutes, it starts first turn; still with rough idle (which wasn't present this morning on my daily commute - or for most of the drive home).
The sequence is repeatable; but it never did this before 5:20PM tonight. I have even driven to work today like this, and disconnected the battery lunchtime when I checked ad - sure enough, it doesn't start.

I have a known broken part load breather, which I taped up as best I could after it broke over a month ago, but I have probably done 1000 miles with it that way. What else could flag the car to not even attempt to start?
Could it be a security issue?

Any ideas?

 

(I hope you know P1111 is a status not error code.)

Next time it's idling rough look at fuel trims. My guess is that there's an air leak.

If so, that's a separate issue to not even cranking.

One extra thing that happens when you disconnect the battery (at least on other cars and S-Types) is that KAM (keep alive memory) is cleared so learned values are lost. The next start will be a bit rough for that reason so you may not have an air leak (or could have that as well).

I don't know if there's something in KAM that would affect cranking. I don't think there is.

So... what enables cranking? A solenoid I think and the starter's brushes need to be OK. Over to you...

 

It doesn't strike me as a security issue, but maybe a connection corroded. There are many connections in the starting circuit, from the main fuses in the boot, bulkhead and solenoids, to the ground strap between the engine and frame. Wet weather can certainly exacerbate a poor connection situation. I assume you have cleaned the battery connections already.
Disconnecting the battery for 10 min. is a like a hard reset where you touch the neg to the pos. post to discharge condensers and cause the ECU to readdress the other modules, so it's not out ft the realm of possibility that you have a module problem.
The rough and high idle could just be a reset condition, but it should return to normal after driving. I think you will find the P1111 is P1000 after the reset. It just indicates internal tests incomplete.
This jagrepair article may help:
JagRepair.com - Jaguar Repair Information Resource

 

If you want to check the common electrical issues, use the link in my signature to check it out. Given how yours is behaving, i don't think it is one of those items, but it's good to eliminate the easy and common snags before chasing the more unusual ones.

When it dies not want to crank, try wiggling the shifter, or try it in neutral.

Good luck!

 

Thansk for the messages, I forgot to try it in Neutral. Car is now stuck at work about 6 miles away. Before I left it though I checked again for error codes.
The system reported none, so I do think this is a connection issue.

I just found the electrical diagrams and it's a lot more complex than, key, solenoid, starter! The Body processor module (also labelled Engine Cranking Control) which appears to do the Start/don't start decision, and feeds the starter relay...which feeds the starter motor, is hidden behind the passenger side dashboard.
Anyone know an easy access route?

Just found the starter relay, in the cubby hole with the toolkit (both LHD & RHD)...I might try to get to car before dark.

 

okay, so I got someone to drive me back to work in the rain and almost darkness, tried Neutral. No Joy.
I tried to get to the starter relay but those B*(&^^$$ at Jaguar used some weird security screws for the cover over the relays in the toolkit area. Nice!
But my assistant said he heard it clicking when I turned the key.

I couldn't see the starter in the dark and rainy night so had to give up there, but it is leading to think it could be starter. Never had one go this early on any car.
Sold my last Vauxhall at 185k on original starter.
Still no error codes, so this may be it.

 

I think the problem may be the security system not recongnizing the key. I have had this problem where the the starter will not work after just driving the car and this is what I do. Try removing the key from the ignition, lock and unlock the car from the remote, re-insert key. If the car now starts you found the problem. My car sometimes does this when I switch between sets of keys.
As RJ mentioned the roung idle after disconnecting the battery is normal

 

The battery cable connection on the false bulkhead can get loose and cause the problems you are experiencing.

bob gauff

 

Hi Bob,
Thanks, but where do you mean? The connections near the battery, or the other power distribution points?

 

2 more thoughts:
1. anything you've disconnected and reconnected - check tight and there wasn't another wire you overlooked
2. if it is a PATS system and it's deliberately not starting then it'll flash a code during the attempt to start so watch that light

 

Polibon, Bob is talking about a power stud under the bonnet that comes out near where you all have a tool kit. It can cause grief if not a great connection. The ground strap at the battery is another spot.

 

Polibon, have you looked at my troubleshooting section?

 

Hi All

I think Paul is on hols for a few days, so normal service will be resumed soon!

Regards

Geoff

 

Cheers everyone! I am currently on holiday in my partners Renault, delivering a bureau to Genoa, Italy. It's a tough job, but someone had to do it. Luckily it doesn't fit in the Jaguar.
I will be back on the 16th and will try again. The car is still stuck at work, so any more ideas that could save me a £ 75 towing bill to bring it 6 miles home are appreciated.

Anyone know how to get at the control module I mentioned earlier? If I can get to it and meter the pins I will know where to look.
Also, where is the neutral switch, so I can rule it out? Is it part of the rotary switch, which just got replaced?

All the best from the French/Italian border.
Paul

 

P1111 code means nothing at all, ... Just means codes have been taken and now cleared, just ignore that code!

This info comes from Jaguar itself.

 

That's not right, best to read the previous posts which explain what it is and were taken from the workshop manual.

 

@JagV8 : I don't understand your post, can you explain please?

Can anyone help with the neutral switch please? Is it part of the gearbox rotary switch (which was replaced recently), or is it inside the car in the J gate?
I can't figure this out from the wiring diagram or the manual.

I will try to check the voltages at the starter relay and see if that has power tomorrow.

 

Okay, so I couldn't sleep for thinking about this and so I found out from this:
http://www.jagrepair.com/images/Auto...ch%205HP24.pdf that the Neutral switch is part of the rotary switch, so that is a start.
But in the pdf it mentions being able to see the status with a datalogger. Can anyone tell me if any of the OBD2 readers or lower cost diagnostic readers can report this? my Jag specialist has a tablet like gadget which could read it when plugged into OBD2...but he is 120miles away.

 

Look at this other thread (Help car wont start) post# 5:

https://www.jaguarforums.com/forum/x...ething-112766/

Gives location of fuses & relays protecting Starter & Starter soleniod, also has photos of False Bulkhead and its location.

Jim Lombardi

 

The P1111 explanation was completely wrong. Just ignore the post.