695/5000
Hello friends, I bought an xj6 sovereign 1992 v6 4000cc automatic with 100k miles, the old owner seems never to have maintenance or oil changes to the transmission is ZF 4hp24 gives many problems,

-P does not park sometimes gives a few quick sounds when I want to stop the car completely, nor does it serve to start the car very rarely
-R works but hits when it enters
-N Start the car
-D the car walks but does not make gear changes
-3 and 2 work although I think that only gear 2 is the only one that works correctly.

We clean the body of valves and change oil and still it goes on, what else can I do before having to change it for another one that works?

Thank you in advance
Jairo

 

Quantity of fluid is very important - you have to measure fluid level with car warm and engine running. Move the gear selector through all the gears a few times then go dip the fluid. It should be at the hot mark. If it isn't, and you have too little, or worse, too much, you WILL have issues shifting etc.
The P issue is a problem with the adjustment of the selector switch on the shifter, nothing to do with tranny AFAIK

Do you have the tranny light lit on the dash when the car is running?

Larry

 

Larry thank you very much your answer, yes tranny light lit is on all time.
What type of fluid you reccomend?
regards

 

Tranny light on (limp home mode) makes the transmission stay in second gear. (I think)

This hasn't happened to me but I've read posts by others on the problem. apparently it can be caused by oil contamination of the throttle position sensor or contamination of the throttle position sensor harness plug.

Sounds like you have a few different issues going on but these transmissions are really reliable and rarely fail so you probably don't have a problem with the tranny itself but with controlling issues that affect it.

BTW I use Dexron 3 equivalent in my car but that might be hard to get where you are.

Wait for someone with more experience with transmission issues to weigh in on your problems, I don't think you need a new tranny!

Larry

 

Do you have the ON-BOARD DIAGNOSTICS ZF 4hp24 PDF for Jaguar ?
Thank you
Jairo

 

That only applies to OBD11 cars - the XJ40 is OBD1 so you can't pull transmission codes.

Larry

 

Hi Jairo,

The transmission warning light often indicates your transmission is in "Limp Mode" or "Limp Home Mode" (LHM), which locks the gearbox in 3rd gear.

On our '93, the most common cause of LHM was oil contamination of the electrical connector for the Throttle Position Sensor (TPS). The connector is mounted to a bracket on the intake manifold elbow just to the left of the Throttle Body (TB). Try disconnecting that connector, flushing both halves out with zero-residue electronic contact cleaner, allowing it to dry or blowing it out with compressed air, then reconnecting.

John Ping published an excellent diagnostic procedure that helped me find failed solder joints on the circuit board of the Transmission Control Module (TCM) in our '93:

Jaguar XJ40 ZF 4HP24 Transmission Diagnostics

The original transmission fluid specification was Dexron IIE, which was superseded by Dexron III, but GM deactivated its licensing of Dexron III in 2011, so fluids called Dexron III are no longer available. However, there are some good equivalents. In the U.S., the most widely-available correct fluid for the 4HP24 is Valvoline Dex/Merc, the conventional type in the blue bottle, not the synthetic version in the red bottle (which is too thin). Other good options are Mobil 1 ATF and Redline Oil D4 ATF (which is the best I've found but has to be ordered). Do not use Dexron VI because despite claims that it is backward compatible, its viscosity is significantly lower (thinner) than Dexron III and your transmission may not operate properly on it.

Cheers,

Don

 

Thank you very much! help me alot!
But I cannot find where is located TPS, if you can send me picture I really appreciate!

Regards

 

Hi Jairo,

The TPS is on the underside of the Throttle Body (TB). The electrical connector you need to clean is mounted on a bracket on the intake manifold elbow to the left of the TB. Disconnect that connector and flush both halves with zero residue electronic cleaner, allow to dry, and reconnect. If your problem still exists, follow the diagnostic procedure I linked to in my earlier post. Here are some small photos of the TPS (the red plastic part) showing how it mounts to the underside of the TB. Hopefully you will just need to clean the electrical connector and won't have to remove the TB to access the TPS:

Welcome to Jag-lovers - Members Photo Viewing Page

Cheers,

Don

 

TCM faults can be read with PDU.(good luck finding someone with a working unit and the software CDs)