I have a 97 XJ6L with 182K miles on it. This last week I am intermittently getting a transmission light and of course it will only limp along after that. It has only happened 3 or 4 times and seems to resolve upon restarting the car or letting it sit for 10 min or so.
My coils are good and recently replaced at about 120K miles with good ones. My valve cover is currently clean no sparking and I have new plugs with good connections to the coils and dielectric grease. The battery is less than a year old and I have cleaned all my grounding locations both in the trunk and the 4 under the bonnet. My transmission fluid is clean clear. Any ideas? Last transmission service was about 100K. I am not leaking fluid either.
Any ideas anyone?
Steve

 

Editing , I'll have to reword this initial discussion better in the morning after kidney dialysis / the big suck .

By it resolving after cooling down a little bit anount but not completly down points to a sensor inside the transmission . This would bedifferent then a quick on - off cycle of the system which you may have looked for / There are 2 intelligence signal sending sehifting the transmission as wel as probably downshifting it . there are commanding dhifting valves that when reated up open a brocken wire on the solinoid windings ( common mode afnsors insifde the transmission that when faulty would prevent the transmission ECU from ups










Reading the transmission connector on M'Lady Penelope :

The module is under the right side footwell and the connector will wringle off but requires the removal ( 8 mm ) of the module in order to latch the connector closed .

The blue pins will read 348 ohms at 86 F and cool transmission fluid

and between the green pins will read about 1025 ohms .

And the reds :

yellow ti orange 6 = 3 ohms pressure regulator

yellow to red 5 = 7 ohms shifting solenoid MV - 1

yellow to red 24 = 29 ohms shifting solenoid MV - 2

yellow to red 42 = 34 ohms shifting solenoid MV - 3

Ideally the reds should read the same but they don't in my case .

What you don't want to see is a open or extremely high resistance reading .

To watch it fail you would have to heat the transmission fluid up to the temp of the observed failure .

These devices are easy to replace yourself .

But before you were to change these devices I would clean the aft rear transmission housing connector that these wires run through as is causes problems from forum readings .




Or you can spend some bucks and a transmission shop can read a latched transmission CEL code with a reader that sees the " T " codes . You should have one latched in memory since you have the transmission light . If you are luck you might find a auto parts store that will read it with a reader that includes the T codes .

See the codes in the attached file :

A BMW dealer would be familiar with this ZF4HP24 transmission as it is used on some BMW models

And a link to the Jaguar / ZF4HP24 nig manual :

http://gershon.ucoz.com/ZF/powertrain-zf.pdfTING

Editing Later in the morning

 

I have a 1995 XJR GM 4L80E tranny, after 2 years of transmission light coming on intermittently and replacing solenoids, internal wiring harness , TCM and ECM, it was as Lady P suggested, check the external wiring harness sealed plug going into the transmission ( loose wire inside no solder). I believe I and my transmission guy have finally found the problem.
Never Happier
Thanks Lady P

Snowball

 

Snowball ,

something you may not be aware on your GM 4L80Etransmission is there are 2 versions in those 3 years resolving a early issue I can't recall . You might reveiw the TSB list and bring something to light .

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