As stated above, I got the warning light just as I pulled into work a couple of days ago but then it cleared after work. Then yesterday it came in and stayed in. No change in performance that I've noted. I haven't pulled any codes yet. Oh well, fluid change was on the punch list, not on my immediate radar. Might have to get bumped up. I assume there's a variety of issues that the ECU could sense that would give you this light?

 

Service level first , probably does not need a drain / refresh of the fluid but....................look for browning of the pink fluid as a common practice

The check engine light CEL codes have few " T " codes for the transmission but can be obtained from a transmission shop that has the transmission ECU reading equipment for free as they want your business , this transmission model is used on BMW and Volvo models

There is a connector ( cars left ) on the transmission body you can clean of oil from the rear edge ( there is 2 tricky D cutouts that is missed ) valve cover gasket without jacking the car to the connector and there is a trick to removing the connector , special different connector

There is a speed sensor in the transmission through pin X and Y that has a resistance high of around 1300 ohms ( the fault would be hard to read ( if the sensor itself ) as heat and transmission vibration related )

The connector pin map is different depending on information sources

Pic and trick coming

The fault on this connector does not show unless low out of park speeds from reading others

Connector on cars left transmission rear

To remove the connector ....................

The barrel must be pulled aft 1/8 inch to unlock and only then rotate counter clockwise looking car fwd

Note the use of large tie wraps to grip the barrel that only has to spin 1/2 turn to come off after lock release

There is some ZF factory and Jaguar TSBs and manuals on this ZF4HP24 transmission I have somewhere

Someone found his transmission ECU connector loose located passenger side very low near the foot wall as a long ribbon connector , ECU manufacture Bosch label

 

W

Excellent, I will try that.

 

There is a little bit of the post refresh / additional info , that's how I roll as I add