Thanks for responses. Do you think a transmission shop would know Jaguar transmission module? And Scottjh9--I have 5 pages of codes. Coventry gave to me. They would clear the codes and have it working but always revert back to faults. They had car for 2 months. Of course if it is the alternator they just blew the diagnosis. Well they did blow the diagnosis becuase they said it was the $3500 Module B in trunk.

Saw on Utube a comparison video between an FX and Lexus. Conclusion--- if you want to avoid mechanical and electrical issues get a Lexus/Toyota. Had a Valient slanthead 6 when I was in college. Put 200,000 miles on it and somewhere I suspect its still driving down in Mexico.

 

The Transmission Control Module or Mechatronic was not made by Jaguar - the electronic portion was made by Bosch, and the hydraulic portion was made by ZF, the German manufacturer of your transmission. The same range of 8HP transmission is used in BMWs, Audis, Chryslers, Jeeps, Porsches, Maseratis, Aston Martins, Land Rovers, Rolls Royces, Volkswagens, Bentleys, Alfa Romeos, Lamborghinis, Morgans, and Toyota Supras. So any transmission shop that works on ZF transmissions should be able to work on yours.

But if you're willing, why not post all five pages of diagnostic trouble codes here and let us see if we have any ideas that may be helpful. With this group, you never know what knowledge is available.

Cheers,

Don

 

Will try to scan and upload . Should prove interesting.

 

regulator replaced. No help. Regulator was producing low voltage (11.3 vs usual 14) but faults still present. That is last repair effort. Dissapointed in Jaguar.

 

I assume you are describing the voltage regulator in the alternator? These days it is unusual for a shop to replace only the voltage regulator/diode pack without replacing the entire alternator. What is the status of your complaint with Coventry Jaguar? How are they going to resolve the matter?

We would be happy to review the 5 pages of diagnostic trouble codes if you will post them.

Cheers,

Don

 

Again listen to Don? The codes are really the only way to fix the car and we don't have them yet?
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Don B-- entire alternator replaced. would that include regulator? I tried to post the 16 pages of faults, Covernty texted to me, I can't post. Emailed to this Forum. Will look for it.

Faults Includes:
UO151-08 Lost communication with restraints control module--Bus Signal--Message Failure.
UO41-68 invalid data recieved from vehicle dynamics control modue--event information.
P2610-87 Engine contrlol module powertrain control module internal engine off timer performance. missing message.
U405-8
U402-00
U002-00
U0121-00 lost comunication withh ABS control module. U0010-88
U0010-88
U0103-00

about 35 diff faults.Would it help to see others? Car drives perfect for about 30 - 40 miles, eco works, then faults start. The spedometer and RPM stop working. All kinds of lights and bell goes off - yellow and then red. Eventually limp lode. Stuck in drive. Stop car. turn off and stuck in drive. After 5 minutes will go back to Park and drive perfectly for while. If I don't drive for a couple of days get more miles before any problem.

So its got to be some basic item. Coventry seems sincere by incompetent. Tested every fuss. Disconnect battery and then clear all faults/codes. Dealer was the one who said regulator. Coventry replaced regulator (and rear Module B last year) Owner said he collects one hour out of 10 billed chasing electrical issues. My old guy won't even work on the car, suspect he knows electical issues are trouble .

Doubt I will sue Coverntry, don't like suing people even if I have been a trial lawyer for over 40 years (any legal questions? send to me,) . But my guess is Coventry's defense would be electricall issues can't be diagnoised with sepcificity and its only a guess. Agree?? Need expert witness

Covernty still has car. Any suggestion for Coverntry? Thanks for all the time spent in reply. Nice Forum!

 

Yes, the voltage regulator is built in to the alternator.


It may very well help to post all of the codes. Whenever we see a lot of "Lost communication" codes, the first thing we suspect is low battery voltage (or low alternator output).

The second thing we suspect is a problem with the CAN, or controller area network, which is the main powertrain computer communication bus. For example, the U0101-00 and U0402-00 codes suggest a problem with CAN integrity to the Transmission Control Module:





Has Coventry cleared all of the codes, then test-driven the vehicle to see which codes recur after it misbehaves? Only the codes that recur will be relevant.

Cheers,

Don

 

Yes, many time Coverntry cleared all the codes. Just Friday received text "After stuggling with your electrical system we finally got the system to reboot and now its working normally. Want to pick up now?" Then later "Opps! Spoke too soon. Warning lights came back on. Will call Monday."

Everything on car works. Faults say brakes not working, battery not working etc. Not true.

More Faults:

U0128-00 Lost communication wiith braking control module.
U0151-00 Lost communcaiton with restriants control module - no subtype information.
U0101-00 Lost communcaiton transmission control module.
P2065-29 Fuel leverl sensor B circuit--signal invalid.
P0460-29 Fuel level sensor A circuit--signal invalid.
P0505-idel air control system--signal rate of change above threshold.
U001-88 High speed CAN communcitonn bus --Bus off.
U100-63 Lost commuincation with engin control module/powertain control module A--circuit/component protection timeout.
U121-63 lost communiction with ABS control module--circuit/component protection timeout.
U140-63 ost communiction with body control module--circuit/component protection timeout.
U12-63 ost communiction with steering angle sensor module--circuit/component protection timeout.
U0103-63 ost communiction with gearshift module--circuit/component protection timeout.

Antilock Brakes
U0001-88 High speed CAN communicaiton box--Bus off

Airbag--Codes: 7

U001-88 High speed CAN communciations bus -- Bus off.
U0121-00 lost communiction with ABS control module--no subtyp info
U010-00 lost communiction with transmission control module--no subtype info
U142-00 lono subtype infost communiction with body control module B--no subtype info
U155-00 lost communiction with instrument cluster control module-no subtype info

You mentioned CAN, or controller area network, Is that the B module in the boot? Replaced.

Ironically, I was driving along and wondering when is something going to go wrong with this car?? Its been 100,000 miles and no problems. Not more than 2 days later--the first fault was "Transmission." That was the only one for a while, then the roladex of faults started.

When car goes into limp mode, when i come to complete to stop, transmission thumps twice and seems to drop down to lower gear.

 

question, can the transmssion control module be tested to determine if broken? Same for the rear Module B junction box. Just wondering, since I had the Junction box replaced--- should it have been tested first to determine if problem? And if it was a problem would not replacing it fix the fault issue??

 

The CAN is not one module. It is the network of wires and associated communication circuitry that allows high-speed communication between the critical computer modules, including the Engine Control Module, Transmission Control Module, Anti-Lock Brakes Control Module, Instrument Cluster, Gateway Module, Rear Differential Control Module, Junction Boxes, the Data Link Connector (Diagnostic Port) and several other modules.

If the CAN is compromised, many malfunctions can occur. For example, the ECM and TCM cannot orchestrate proper gearshifts. This may trigger Restricted Performance/Limp Home Mode, locking the transmission into a single forward gear such as 3rd or 5th, to protect the transmission from internal damage.

Beginning on page 142 (pdf page 158) of the Electrical Guide at the link below are the schematics of the high-speed and medium-speed module communication networks. The CAN runs on two wires twisted together, and in your car, the wires may be White and White with a Blue tracer line.

Jaguar X250 Electrical Guide 2012 -

CAN diagnostic procedures can fill volumes, but one thing I check for in a CAN diagnosis is water ingress into any of the modules connected to the network, such as the ECM, junction boxes, etc., and corrosion on any of the ground points associated with the system.

If Coventry has access to the Factory Workshop Manual, they can follow the pinpoint tests for DTCs that seem most closely related to your primary malfunctions. This should lead them to the root cause.

Cheers,

Don

 

You say this came on all of a sudden. I am not familiar with the engine manage system on your car. I know jaguar went to bosch from denso at some point. I am a bit familiar with the zf trans. Especially the zf6hp26. Yours is different but it should have a bosch tcm. I have personally experienced the tcm picking up slight misfires the ecm does not and the tcm puts the car into limp mode and shuts the can network down and all those u codes set among others. I am getting at possible minor ignition coil or sparkplug glitches. There are a few threads on this you can search up. Something to think about

 

Hi Scott,

On the ZF 6HP and 8HP transmissions, the TCM electronic module is made by Bosch, but it is not a separate unit. It is built into the transmission in a combined electronic control module/valve body assembly known as the Mechatronic (Mechatronik in German).

With all of the recurrent lost communication codes in lloyd's car, it seems more likely that his transmission issues are directly related to communication issues. I suspect that if the communication problems are resolved, the transmission may prove to be just fine, but your misfire theory is interesting!

Cheers,

Don

 

i know what you are saying don but the tcm is removable and made by bosch on the 26. I have taken mine off and sent to bulgaria for repair. Some call it control module some tcm. Dont know about the later zf trans. Conductor plate is more accurate. I was thinking the loss of can comms may be something besides wiring. Thats
all

 

This is the Mechatronic on the ZF 6HP26. It is an assembly that combines the TCM and valve body. The 8HP Mechatronic is similar:



Is that what you removed and sent to Bulgaria? It mounts on the underside of the transmission inside the fluid pan.

The 8HP Mechatronic is very similar. The electronic portion is made by Bosch, but the hydraulic valve body is made by ZF:




The separate Bosch TCMs were used on the X100 and X308, which had the ZF 5HP24. These separate TCMs mounted in the engine bay:



Lloyd's car is a 2013 XF (X250) with the ZF 8HP70 transmission, so it has the Mechatronic combined TCM/valve body.

I think I remember reading about your experience with misfires triggering transmission issues that interrupt the CAN. How did you diagnose the undetected misfires and how did you resolve them?

Cheers,

Don

 

Hello don

thanks as always for your understanding and clarity. I took off the mechatronix and removed the black condutor plate from the valve body. That is what i had repaired. It has a zf id number and a bosch id number on it. The repair shop uses the bosch id for parts and zf for programming. It is not available as a service part. Only used or repair. Technically it is not a stand alone tcm. The way i finally figured my trans issue out was by watching the misfire monitors using my older snap on modis scanner. I had come across a thread on the forum similar to my issue and it was resolved by new coils and plugs. As i watched my misfire monitor it had quite high numbers but not enough for the ecm to set a code. The more throttle i gave the higher the numbers went. Finally went for a drive to put a load on it and it went into limp mode. Still no misfire code but i finally got a checksum error from the trans. Finally figured out the baby multiple misfires were enough to upset the trans monitors. Replaced all coils and plugs with denso and trans has been perfect since

 

Coventry Jaguar Repairs replaced alternator and worked on clearing codes and code faults always come back. Coventry claims you can't check the computor modules for defects, just have to replace to see if its broken. Which is insane at $3500. So suspect exremely poor design plus Coverntry should not be doing electrical repairs. Or at minimum have warning sign out front ""If you have an electrical problem we will look at it but can't guarnaty we can figure out what's wrong or fix it." Buyer beware.

Got the car all the way home, 20 miles with no issues, but faults will come back. The power stearing stiffens before faults start and it stiffened.

Bought car through Price Club for good price and no negotiations. But a $54k car should last more than 100k miles.

 

The adaptive power steering assist depends on communication from other modules (primarily vehicle speed), so this is another indication of communication problems.

 

Is it true one would have to replace all module computers one by one to locate the problem module, if it is a module?

 

The trick is experience with the module codes. To interpret and weed them out. Coventry is right technically about a module being good or bad. There is only codes for the tech to deal with on car. Some modules can be bench tested i believe. But as don stated your root cause is a comm error being caused by something. I wish i knew more about your model year but my knowledge is 2008 and prior. More specifically my 2006. I think the problem will be something out of left field as you say it came on all of a sudden. I still think nbcat in newport beach could help if available