I have a p1777 code and the transmission light is illuminated on my dashboard.

I have tried three different TCMs on the car including the one that was on the car when I got the car with no change. So i suspect that the TCM is not the problem.

Doesn't the TCM communicate with the ECM? How would I verify that there is or is not communication between the two modules.

Any other idea or information that you need?

Thanks,
Jomo

 

http://www.jagrepair.com/images/TSB/...d%20Module.pdf Have you read this. I only could copy and paste. Might need a flash using sdd/ids to upgrade software

 

The transmission control module also communicates with the transmission body as there is a speed sensor inside the transmission

The connector is on the left side rear and points aft

Fluids can get on this connector and can be cleaned

You can get to this connector without jacking but there is a trick to removing it using tywraps ,

See post 24 and 25

https://www.jaguarforums.com/forum/x...etting-worse-2

Its the black one

 

@Parker 7,
Thanks for the reply. The link you attached does not go beyond post number 14 so I can't view post 24 and 25. When you have time can you please supply me with the correct link.
Thanks,
Jomo

 

How would I go about flashing my TCM?

 

Now I remember how that transmission connector works and how I was confusing it with a Bayonet connector

The term DEUTSCH comes to mind but I can be wrong

The 3 / 120 degree post go into 3 spiral groves n the barrel with the white paint mark

The twist to disengage it is about a 1/2 turn

the trick point is the locking feature so it doesn't migrate and rotate loose in service

If you think of the 3 spirals as streets but in this case the 3 streets have a culdisack at the ends that the post park in , to unseat the post as it rest in the coldisack you have to pull a small dimension down the barrel then twist

This works OK if the connector is not internally corroded , but to make it work once it is you have to obey it's workings

To remove it the barrel has to go straight aft as mounted ( about 1/8 inch ) and only then rotate it

This is where soaking overnight with penetrate helps

__________________
Lady P . is a 1996 4.0 N/A Sovereign 110k miles ( 7/31/17 )

 

Here are some TSBs. (the ones NOBODY reads)

 

[QUOTE=jomo;2453321]How would I go about flashing my TCM?[/QUOTE
you need sdd/ids or stand alone ids to flash modules. I am not absolutely sure but your car will use ids. Motorcarman knows for sure. Anyway it needs to be done correctly and with genuine oem setup

 

nothing on this car can be flashed it’s all plug and play.

ids is just to set dealer options and reset the tps/oxygen sensors

 

excellent knowledge xalty. Should have thought it being a 1995 even before the obd2 mandates it would be different. That is why the tsb says replace with updated tcm and not a flash i assume

 

You do not need to replace the ECM, just the PROMs. (as per the RECALL T493)

I replaced dozens when the recall was in 'full-swing' during the early 2000s.

 

T493 pertains to the engine ECU which is a whole different thing outside of your symptoms in my opinion unless there is a issue of the throttle cable not returning to the closed stop idle position giving him problems in " the mix " of things

 

I initially had some engine codes on the car and swapped out the ECM with another one I had. The ECM had a sticker on it which I guess meantthat the ECM had the updated PROMs in it. Well that one is back in my car. I have some things to do before taking the car for a drive. I sure hope that fixes my transmission problem.
This forum is awesome!
Jomo

 

A different ECU with your curren installed TPS and EGR have to be a match otherwise the engine regulation can be off

Do not touch the TPS until you have a understanding of it

The transmission speed sensor inside communicates to the transmission ECU which commands the engine ECU to unload the engine when reaching a shift point

This causes problems in the area of idle that is most noticeable both in terms of the speed sensor and the different TPS matching or " orientation " of the engine ECU

Sometimes you get lucky with a match of a replacement ECU and its orientation and the TPS mounting before TPS adjustment