Had a gearbox fault, dealer said needed a new transmission. Took it to a transmission shop, they rebuilt it, drove 4 days and it went into limp home mode. Shop put the wrong transmission fluid in, now they have replaced it again but it still goes into limp mode after a few days of driving. Shop says I need anew computer, not the computer that runs the rest of the car but the computer that runs the transmission. Is there a separate computer that only runs the transmission? Would this normally have been included in the rebuild or is it something different? Please help!!! 2004 S Type 3.0 123K miles.

 

The 2004 S-Type has a Transmission Control Module located in the transmission as part of the main control valve body---so it's a single electro-mechanical control unit.

If your original issue was properly diagnosed then it should have been fixed during the repair/rebuild.So I suppose the real question is what exactly the transmission shop was asked to do.

I would be really concerned about a repair shop which did not put the correct lubricant in my automatic transmission though.

 

Thanks for the feedback. I took it to Aamco, they have a pretty good reputation and offered a 1 year warranty. I specifically asked if they could work on a jaguar and they assured me they could. I paid $2800 for the rebuild. When the car failed they told me it was the main computer that needed to be replaced, I took it to the dealer for a 2nd opinion, they told me about the wrong fluid. I am getting P0730, P0731 and P0736 codes. Aamco said they fired the tech for the mistake but now they said it is the computer. We are now in warranty work so I want to make sure they aren't trying to get out of fixing whatever their mistake may have caused. They said it is not the main computer but the computer that runs the transmission that needs to be replaced at a cost of $2000.
I could really use some help figuring this out!

 

I am not a ZF transmission expert but those codes are unlikely to be due to the main main computer failure!
How good is your battery?Have it load tested.If it tests poor replaceit have codes cleared and try running your car.

If the problem reappears the codes you gave indicate issues with the TCM/solenoid valve body inside the transmission.

Maybe aforum member in the Atlanta area could help you.

 

I would never take any of my vehicles to AAMCO, particularly one as quirky as the ZF transmission. You do not want a generalist transmission guy, probably with limited training on anything outside of GM, Ford, or Chrysler, turning wrenches on your ZF. Next time, do your due diligence before allowing someone to fiddle with your very pricey transmission....

 

If they have readily admitted the wrong fluid the fix should be covered by the shop.

An industry standard is for most shops to recoup costs at the customers expense. It is quite funny how they are quoting you almost the same price to do the TCM as the whole tranny that you already paid for.

Don't fall for it. Ammco does not have a good reputation throughout the years.
Demand that they fix it at their cost and only their cost.

 

There is indeed a separate computer (TCM) inside trans. However, those codes don't suggest the TCM is faulty but rather that it's reporting faults (via the main one, the PCM). If they replace on their dollar, fine. Maybe it will fix the mess they've created.

 

P0731- Another incorrect gear ratio fault. Maybe gear 1?

P0736 -Another gear ratio incorrect for reverse gear?



I would make sure the fluid level is correct and they used the correct fluid and then I would wipe the TCM adaptations out. Then flash the TCM with the latest Jaguar software.




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