Good morning (afternoon or evening)!

As my kitty car likes to keep me on my toes (or at least really enjoys when I make up a slew of new four letter words first thing in the morning), I'm creating a NEW post for my NEW problem code.

Yay.

So, this morning, I noticed what I've noticed a few times over the last few months: sometimes, my Jag doesn't want to start when I turn the key. Not like the battery is dying (been there, done that) or the store sold you a battery that wasn't fully charged (bought the teeshirt) but a situation I can only describe as uniquely Jaguar. I poke the shifter, make sure it's, I don't freaking know, fully in park for whatever reason, and try again, and it goes.

I've also noticed my fob is getting picky about when it works (sometimes I can unlock / lock the doors from a good, normal distance, sometimes I am actually poking the car and it still won't go; battery in fob is fine / was replaced not too long ago, though). I have a secondary one that needs reprogramming.

Well, this morning it was full on special mode, and my little Jag is currently a Ford, because she refuses to behave properly. She did her weird "I don't want to start" thing, although she did after a moment. As I went to pull out, my son goes, "uh, wtf happened to your dash?" Everything had gone into "brick" mode: all gauges not reading, odometer was all dashes, and all lights (red transmission light, CEL, etc) on. This is the second time I have seen this happen (first time was nearly two years ago). Both times, I turn the car off, and have problems restarting (the anti-theft seems engaged? red light for it blinks like mad when it's refusing to start, and it only starts when it goes away). Eventually, I locked the car and unlocked it via the fob, and was able to restart, with the problem code of P1638.

Because more than 24 hours without seeing that damn CEL was too much to ask for? Heh.

I've done some searching around the forums for similar threads, but it was wisely suggested to me that I post my own experience in hopes of maybe narrowing down possible causes and thus fixes.

Is it too much to ask that, perhaps, my fobs are the fault here? (Causing an alarm trip or something of the sort?) I could really use a cheap problem for once, lol.

Thanks.

 

Sounds like your victory was short lived. That code refers to a CAN issue. See this thread. There is an excellent PDF posted by Paul that explains what it is and how to track down the issue. Could be a connection or wiring issue or you could need a new ECM or instrument cluster. Check out this thread:

https://www.jaguarforums.com/forum/x...ighlight=P1638

 

Could be the weak battery thing..............

 

Whelp, whatever it is (and, really, the idea of the instrument cluster makes me want to cry, so can it be something EASIER?? sigh) it's back and it's staying.

Went to pick up my son from school last night, turned the car off for a 10 minute wait, came back, put car in drive, dashboard "bricked" again. Pulled right over, turned the car off and it started right back up, and was able to drive home. Same code @ p1638, of course.

This morning, went to start the car, the dash zeroed out. Turned her off, she would NOT start back up for a while (key in, lights on dash on, nothing from the starter, etc.) Finally got her back on (fiddled with the steering wheel, seemed to work, but I've no idea if that's a coincidence) and the dash bricked right away. Moved her spots just to see what she'd do... and bricked right away.

So... I'm mad. And the damn car is a Ford again at the moment.

I'm going to check the battery when I get home tonight, provided I can borrow a volt meter, and start there. Sigh.

Could something have been knocked loose when all the other work was being done?



Also, I've been reading through the posts here, and on other sites, and I saw this and wondering how accurate and/or helpful it would be:


Thanks...again. :P

 

Simplest thing would be to change the battery, or at least make sure it gets a load test. Weird things happen to the X if the battery is not outputting what it should. I see you are in Phoenix and the extreme heat could have an effect that way.

The other thing might be to check your ECM and wiring to make sure the connections are good and there isn't a ground issue. By chance, when you have your issues is it when it is raining or soon after? Could be water getting in there.

 

New battery...............

 

Was just coming to post:

Battery is fine. Had it checked at 2 different places, as well as with voltmeter. (I was REALLY HOPEFUL, sigh.) Only possible oddity was first place said alternator was toast, but told us to have it checked elsewhere as reading is not always correct. Second place checked it twice, and said everything checked out fine.

Car would NOT START for the longest time today. As always, the anti-theft light was engaged each time we tried to start and couldn't; it was when in finally stopped blinking that the car started.

The CEL has also gone away of its own accord. Of course.

Tom has my car for now. Again. The poor man. He's going to check pin connections, etc.

Thanks for all the input/help, all.



[edited to add]: negative on the rain, although I DID have a car wash the day it went crazy again...five hours prior.

 

The reason I asked about the rain is I wonder if water might be leaking into the car and getting into the ECM. Do you ever notice water in the car if it rains hard or you go through a car wash? Just spit-balling here. If your instrument cluster is acting weird and your anti-theft light is blinking maybe it is related to your CAN bus fault code. That is why I said to check the connections and wiring. Maybe something is loose and causing and intermittent issues. Random electrical issues like that could be a pain to track down. Good luck, wish I could offer more than just sympathy.

 

PATS light flashes to signal a fault and if it does it for long enough outputs a code (count & see the pattern) to say why it's unhappy.

 

I don't know how I missed your post, but this is exactly how I have more information now; thank you. Issue happened again this morning for the first time since my last post, and I got code 16 from it. (I've learned if I let the damn thing blink out its code, it's happy [as can be, anyway] and I can start the car again.)

Code 16, according to this, is certain pins to the ECM. Probably. (Would make sense given my CEL code?)

I also saw this post about certain fuses, so I'll take a peek at those too.


I've no idea how much of an issue this is going to be to fix, but I have to say, I feel much better having information!

Thanks, all! (And for the sympathy too, Alfadude; I need it! :P )

 

I have code 16 as a fault between the transceiver and the (well, relevant module) and that it can cause: a crank/no start. Sadly the short description does not mention where to go with a view to fixing it!

At a guess (sorry) the transceiver is the part that picks up the key transponder - usually a coil of wire under the steering column shroud. So, could be the transponder is failing (try a different key) or the coil is at fault (more likely its connections etc).

 

Sooooo... after over a month of chasing this problem down (trying from the least PITA and least expensive and working our way up) with no resolution and increasing problems (no crank/start at all as of last Friday; dash would "brick" right away) Tom had a stroke of genius and lifted the cover to the shifter, gently poked the six wires there, and the car started right up. I drove it to his place with NO issues (which, at that point, was a bloody miracle in itself). He spent some time Saturday cleaning the entire area out (he'd be much better suited to share the technical terms than I, of course, but my understanding is some electrical cleaner, connectors, something something circuit board ).

That was Saturday, and so far, so good - knock on wood. I've done so much reading on this and it seems that electrical gremlins of many kinds can cause Kitty to become unhappy, so I'm hopeful it was as simple as "your cupholder sucks, stop putting your coffee there."

Time will tell, of course, but I hate leaving these threads with no resolution.

Thanks again to everyone for the fantastic help, as always!

 

Have you had any issue since?