[xj-s] Transmission Issue Saga Continuing

XJ-S
1

Well, I finally got Superblue back yesterday after
replacing the TCU with another one. The tech assured me had
taken her for a test drive and it didn’t crop up during the
drive, so it appeared finally fixed.

So, I go to drive Superblue home and get no more than a
couple of miles down the road when the issue DOES crop up,
yet again. &8-( (I also noticed the driver’s seat issue
was not fixed, or if it was then it blew another fuse
somehow during the test drive). After turning the key off
and waiting a few seconds, I started her up and drove about
another 2-3 miles and almost made it home before the issue
cropped up again. This time it seemed to also be HARD-
shifting not only between 1-2 gears but 2-3 gears as well.
I drove her on home and parked her, for who knows how long.

The shop says the only remaining possible culprit would be
one of two solenoids in the tranny. Anyone know how those
can be tested if pulled out (I think the tech said the tran
pan would have to be dropped), and are they available and
typically how much do they run $$?

At this point I’m getting so sick of it all I’m thinking
of peddling her off … I know if I ever buy another XJS it
will be like Supercat and be a '95 (or '96). The plugs may
be harder to change and there be coil/coil wiring issues,
but at least you have OBDII to tell you WHAT is wrong.–
&:slight_smile: Paul '94 XJS 4.0 cp. (
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

// please trim quoted text to context only

2

In reply to a message from AttyDallas sent Tue 25 Oct 2016:

btw, something else that made the tech think the TCU may
have indeed been the culprit. He noticed a faint line
diagonally down the front of the cover. Everything beneath
that line on the cover seemed to have some ‘‘spotting’’ on it.
His idea was that maybe at one time the car had been in
water/a flood and that water had gotten inside the TCU
somehow, eventually causing the issue. Oh well, it’s apparent
now that was not the source of the tran issue.–
The original message included these comments:

Well, I finally got Superblue back yesterday after
replacing the TCU with another one. The tech assured me had
taken her for a test drive and it didn’t crop up during the
drive, so it appeared finally fixed.

–
&:slight_smile: Paul '94 XJS 4.0 cp. (
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

// please trim quoted text to context only

3

<Date: Tue, 25 Oct 2016 13:09:38 -0700

Well, I finally got Superblue back yesterday after replacing the TCU with
another one. The tech assured me had taken her for a test drive and it
didn’t crop up during the drive, so it appeared finally fixed.

So, I go to drive Superblue home and get no more than a couple of miles
down the road when the issue DOES crop up,
yet again. &8-( (I also noticed the driver’s seat issue
was not fixed, or if it was then it blew another fuse somehow during the
test drive). After turning the key off and waiting a few seconds, I started
her up and drove about another 2-3 miles and almost made it home before the
issue cropped up again. This time it seemed to also be HARD- shifting not
only between 1-2 gears but 2-3 gears as well.
I drove her on home and parked her, for who knows how long.

The shop says the only remaining possible culprit would be one of two
solenoids in the tranny. Anyone know how those can be tested if pulled out
(I think the tech said the tran pan would have to be dropped), and are they
available and typically how much do they run $$?

At this point I’m getting so sick of it all I’m thinking of peddling her
off … I know if I ever buy another XJS it will be like Supercat and be a
'95 (or '96). The plugs may be harder to change and there be coil/coil
wiring issues, but at least you have OBDII to tell you WHAT is wrong.>

Paul,
It appears you’re going in the same direction I did this past year. If you
have not been able to find a shop that can read the OBD 1 codes, I strongly
suggest you stop right now and find a way to trouble shoot the individual
wires that connect to the TCU. If you don’t have a copy of the 1994
Electrical Guide, here’s a link that will take you there.

http://www.jagrepair.com/images/Electrical/Elect-Tech%20All2/94%20XJS%204.0L
%20Electrical.pdf

Go to figure 26. It provides the values you, or your technician, should
read when testing each wire. The connections include the solenoids inside
the transmission. If the tests indicate a problem, then you can go in that
direction. In my case, after replacing the TCU twice and before finding a
way to test the TCU connection, the reading for GH5-25, engine control
module, was 10.8V and not the correct 12V. If the tech that did the testing
knew this really meant the engine control module was not sending the correct
signal to the TCU I would not have had to find a shop that was able to read
the codes and tell me that they picked up a code “26”. Page 41 of the
following attachment provides a listing of the transmission trouble codes.

http://www.jagrepair.com/images/Training%20Guides/200_1996.pdf

The Jaguar PDU will read these codes but you can do the connection testing
described in the first attachment if you can’t find a shop with a PDU.

With regard to the availability of the solenoids and other transmission
parts, they are all available. A good service shop can obtain them. The ZF
4 HP 24 transmission has been used on other automobiles and is very
serviceable. The transmission shops I’ve talked to tell me their opinion of
the transmission is that it’s bullet proof and is a very solid transmission.

With the two documents above, you and your technician should be able to
solve the problem.

Good Luck,
David Reinke
1994 XJS 4.0 2+2 Convertible
1969 E-Type

// please trim quoted text to context onlyFrom: “AttyDallas” attydallas3@aol.com
Subject: [xj-s] Transmission Issue Saga Continuing …