[xj40] Quick pre-purchase tech Q's + XJ40 owners in Marin?

XJ40
1

I’m looking at a 1991 XJ40 Sovereign for purchase (I’ve got
5 vehicles, and they’re ALL 2-door, and I now have need for
the convenience of a 4-door sedan). It’s got a few issues
to be resolved.

At the moment, I’ve got the original (non-PDF) version of
the JDHT CD-ROM for XJ40 models (incl 1991 data). However,
I don’t readily see anything which identifies which fuse is
which by number as used by the VCM display: description of
the VCM seems limited to the EFI type error codes.

The VCM displays ‘‘FUSE 5’’, then ‘‘PAD’’ (Or PRO, for all I
know - they’re standard LCD segments as you all know).

Which of the multitude of 5th fuses is ‘‘FUSE 5’’ ? I can
identify at least six different fuses which have a #5
identifier.

I suspect ‘‘PAD’’ refers to brakes. The seller (agent, not
specializing in Jaguars) indicates that brakes have recently
been serviced, including replacement of two ABS wheel
sensors (there’s still an ABS warning - I’m quite prepared
to live with it in the near term and tackle it as a project
in the longer term).

The owners handbook is nowhere to be seen at the moment, so
I can’t readily look this up, and I’m a bit reluctant to
order up a secondhand manual for an automobile I don’t yet own.

Second issue - how would one release the passenger passive
restraint - it’s been unclipped from the shoulder track, but
the belt seems not to want to release release from the
sheath alongside the console to allow it to be reattached to
the RHS passive track.

If the radio code is indeed possibly on a sticker under the
bonnet (as per the online XJ40 tome), whereabouts on the
underside of the bonnet might that be? I neglected to check
when inspecting the car this afternoon, but when I go back,
I’d like to avoid looking around too long.

On the plus side, the sunroof is operational, as is the
cruise control and A/C. Coming from the XJ-S crowd, these
are small miracles, since they’re often problem points.

Lastly, if there’s an XJ40 owner in Marin County (you know
who you are!), preferrably in the San Rafael area, I’d
appreciate hearing from you offlist - I’ve got some
reservations about the apparent lack of power in the example
which I drove when it came to steep hills (on straightaways
it was fine), but I’m not sure whether that’s because I
consider my wife’s 5.0L Mustang a ‘‘small’’ engine (of the
cars we own, it is!), or because there’s a power issue with
this example I’m checking out. I feel that I should be able
to hit a steep hill (of which we’ve got some nice ones here
), lean into the gas and expect to accelerate on up -
sure, the 4.0L six is going to heff and haw more than a 5.3L
V12, a 5.7L V8, or a 7.4L V8, but I’d expect it to do better
than 35mph or so after several hundred feet.

Am I expecting too much of it, or does this example show
indications of an engine power problem (at 94K miles)?

Thanks for any insights.–
1988 XJ-SC / 1985 XJS / 1969 Buick GS
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !

2

Sean

It should display FUSE 1, 2 or 3 meaning RH, LH or centre fuse box has a
duff fuse. Are you misreading the poor display?
The word is PAD and it should mean “Brake pad worn thin” but may be because
of a faulty wire or sensor on the pad.
Performance up hills - it should go like stink! For my car to do only
35mph, the hill would have to be nearly vertical! However I don’t know
what’s wrong - maybe bunged up cat on exhaust?

Norman Watkins----- Original Message -----
From: “Sean Straw” sean.straw+jagadmin@mail.professional.org

The VCM displays ‘‘FUSE 5’’, then ‘‘PAD’’ (Or PRO, for all I
know - they’re standard LCD segments as you all know).

Which of the multitude of 5th fuses is ‘‘FUSE 5’’ ? I can
identify at least six different fuses which have a #5
identifier.
but I’d expect it to do better
than 35mph or so after several hundred feet.

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !

3

In reply to a message from Sean Straw sent Wed 16 Jul 2003:

Sean,

This from my owners handbook ;-

  • Brake electrical supply failure:-
    Brake system fault and circuit failure warning lights will be
    illuminated and the words FAIL and FUSE 6 are displayed.
    — Car must not be driven, go to dealer

  • ABS electrical supply failure:-
    ABS system fault and circuit warning lights will be illuminated and
    the word FUSE 5 is displayed.
    — The brake system will continue to function without the ABS

  • Circuit failure:-
    Fuse 5 identified - check in-line fuse for the ABS ECU (main relay)
    Fuse 6 identified - check in-line fuse for the braking system pump
    motor.
    — If fuses OK, go to a Jag dealer

Both in-line fuses 5 and 6 are described as being 30 Amp, light
green, above the inertia switch on the driver’s side.

Other than these two, the VCM does not identify any defective fuse
by number. It merely tells you which of the three fuse boxes to
look in - circuit 1(LH footwell), circuit 2 (RH footwell) or
circuit 3 (centre armrest) IIRC.

The VCM message you see and the ABS warning are undoubtedly related.

Can’t help you with the passive restraint - fortunately we don’t
have such abominations over here - but I understand the Jag dealers
in the US are bound by Fed law to fix them for free, forever.

Oh, and a 4.0 Litre AJ6 will pull an XJ40 up the side of a house if
it’s working properly!–
Bryan N ('91 Sovereign 4.0 L)
Cambridge, United Kingdom
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !

4

In reply to a message from Bryan N sent Wed 16 Jul 2003:

Thanks Bryan, this is useful info. Looks like the ABS
failure might be an easy fix then, which is great news,
since I already know it can be a pricey thing to fix by
replacing certain other parts.

I’ll bring a spare fuse with me on the next visit (and, as I
understand, a standard 30A automotive fuse - double throw?).
I’ve already printed the fuse listings from the WSM. I’ve
now annotated them with the FUSE # information for reference.

Thanks also to Norman who provided some additional insight
(though my initial replies were offlist because I’d also
received a separate email copy of his post).

I guess at this point, my two reservations are ensuring that
there’s not a water problem (what seller can refuse having
someone else wash their car for them?) and getting a fix on
the uphill acceleration.

The more I think about it, the more I suspect that my
expectations of acceleration from a standstill at the foot
of a ~40% grade or so are unrealistic for a naturally
aspirated six-cylinder motor. Everything I’ve got to
compare it with has appreciably more oomph.

I’ll endeavour to check out another XJ40 locally and see how
it compares - now, just to find one – with as many Jaguars
as there are in this region, it’s quite surprising that
there are so very few of them in the adverts.–
The original message included these comments:

Fuse 5 identified - check in-line fuse for the ABS ECU (main relay)

–
1988 XJ-SC / 1985 XJS / 1969 Buick GS
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !