X308; Multiple error messages; won't start

X300
1

Hi guys!
I was called out to help with a friend’s car the other day, a 1997 Jaguar XJ8 3.2 litre. It was driven onto the lift for rustproofing (Fluid Film) and afterwards it wouldn’t start. Actually, it wouldn’t budge at all, so first I had to tell them how to get the gear lever out of Park…

Somebody suggested that the ECU was fried, so I brought a working one, but that didn’t change anything at all, so I put the old one back in.

I was told that problems - although not specified - had arisen previously out of not waiting until the ‘System check’ message had disappeared until hitting the starter, which tells me that something’s wrong as, In my experience that shouldn’t matter on a healthy car.

The displayed messages (please see video below) loop, and when the key is turned to the start position, it doesn’t engage the starter at all, but the ignition lights dim slightly (battery should be healthy (green dot to be seen) but was only 12,4 volts when I measured it). The battery has been charging overnight, but it was no change when they tried this morning.

I also thought about the obvious ‘dodgy earth-connection’ scenario, so I fed a massive ground cable from the battery to the engine, to no avail, so I removed that. Measured multiple points in the engine bay, and found good earth connection everywhere…

The remote control didn’t work at all, so I tried the re-program procedure; no chirp after flashing the lights 4 times, so it never entered programming mode.

One thing I noticed that our own XJ8 doesn’t do, is that the temperature gauge rises and then drops when the ignition is turned on.

Any wisdom that can help us with this case is greatly appreciated!

Kindest regards,
Bard Thomas

2

Hi Bård,

Maybe the rustproofing firm dislodged the transmission electrical connector or “gummed” it up so that the transmission is no longer communicating with the car.

Also, these firms tend to seriously power was the underside of the car before applying the underseal. Maybe, water got in someplace it shouldn’t have

Kind regards,

Chris

Tel. :- (+47) 915 62627

3

Hi Chris,

I have thought about the transmission connector, but it is normally very well secured, and this kind of undercoating does not require heavy washing. Actually, it was only used pressurized air to clean it. No water!

Do you reckon these messages might originate from the transmission connector…?

Bard

4

Hi Bård,

I know that the connector is not particularly well designed and is located in a place of extremes. It often doesn’t seal properly then water/dampness gets in and results in a “fault” of limp home mode. It is even known to completely disconnect

But, on our cars, who knows what the computers do with fault info!!!:joy:. Often, no one fault seems to throw up the same symptoms and messages/codes!

Since the car died on the “operating table”(rust protection firm), I would tend to search for causes that coincide with the immediate situation change, I.e. underseal contractor. If somebody has been bowing compressed air around electrical connectors, wiring, vacuum hoses etc, this seems like a worthy candidate for investigation.

Kind regards,

Chris R. Gates

Tel. :- (+47) 915 62627

5

If the battery is completely duff and unable to take a full charge, low battery voltage can throw random faults. Have you tried a new battery? Needs to be properly connected, not just via jump leads.

Frankie

6

Hi,

Please disregard the comment about waiting for the ‘System check’ to finish! This was a misunderstanding, which leads me to exclusively look for faults originating from the immediate work done on the car; rust proofing!

No water was used, only compressed air but, as commented by Chris, this may very well be a reason for connector problems, so I’ll start with the gearbox connector…

Bard

7

Hi Bard,
my name is Jan and I´m from Slovakia. I think that I have the same problem with many fault messages on my X308 as you few years ago. Can you please remember how did you solve the problem?
[Jaguar X308 fault messages - YouTube]
The problem occurred after disconnecting the battery (for apx.2weeks) and repairing the body.
Thank you in advance for any help
Jan

8

Hi Jan,
For your issue, I would definitely locate and clean up the main ground lead between the body and transmission/engine (bell-housing). I had multiple faults when diagnosing (Autel ODB-II) my daughter’s XF. Cleaned up the ground connection and was able to erase all the faults and ran a new, clean diag! Everything gone!
One more thing, even easier, that you can try, is to hold the disconnected battery leads together for 10-20 seconds and then connect the battery. This may ‘reset’ the electronics.

Good luck!

Kind regards,
Bard

9

Hi,
thank you very much for your advice, I will try both ways and see.
I’ll let you know
Regards
Jan

10

Hi,
so unfortunately without any success.
I’m completely at the end.
Any idea?
Jan

11

Have you run a scan to see what codes you are getting?
Also will the engine turn over?

12

Yeah, I was going to suggest that as well. Get hold of some kind of ODBII reader with a Jaguar-program (or even with a generic one), just to get some clues.

BTW; did you replace a part, for instance the ECU?

Bard

13

Hi,
unfortunately I don ´t have any testing instrument at home and car is not possible to move anywhere.
Jan