Don't know when the previous owner added Dinan mods. I am guessing sometime early on. It has 134k now. No transmission repairs. I do trans flush at regular intervals which is important and most don't do it which leads to bigger problems.

I agree. I have flushed transmission every 40-50,000 miles with ZF fluid. I did the Dinan mods at about 2,500 miles. Seems to me there must be some reason that our transmissions are still doing fine since they are stressed more than the norm. I did replace the heat sensor. Flushing the transmission and/or Dinan transmission software are the only reasons I can think might be the reason for me unless driving hard all the time helps.

LN76346

Replacement of the heat sensor: Is that inside the transmission or outside of it? (i.e., does the transmission fluid need to be drained out, and pan dropped to access)

Thanks and Welcome! Registry updated

That's inside the transmission so you'll need to drain the fluid and drop the pan. The heat sensor is actually a part of the wiring harness so you have to replace the whole thing. Fortunately it's quite easy to swap out and is literally an unplug and plug in affair. The harness costs $119 from here: Valve Body Harness 5HP24

And here's a great DIY: DIY: 99-01 BMW 5HP24 (ZF A5S440Z) pulse generator (temp sensor) & harness

Just make sure that your symptoms match up to temp sensor failure and not something else.

Thanks Danny, fantastic DIY.

I guess my symptoms are similar, it's the common 2-1 downshift lurch and it's only present when the vehicle gets to normal operating temperature. Which makes me think it's a temperature reading related issue.

Sucks to have to drop the pan since I already did that only 5,000 miles ago when I did fluid and new filter service. That ATF is expensive!

Before you drop the oil pan and replace the heat sensor, plug in some kind of real time scan tool that can read the transmission temperature. If the sensor is on the fritz then it'll show some crazy number. My 540it had that issue in the winter, it would show the transmission temp as 130ºC after sitting all night! Now if the transmission temperature sensor is working and showing a correct number (as in, it starts cool when you start the car and rises as you drive) then that's not the issue. If the sensor starts showing a really high temperature when the car is at operating temperature, then you might have other issues like a bad transmission thermostat or a bad transmission heat exchanger. That's a very common issue with the early L322 Range Rovers (same M62tu and 5HP24).

Symptoms are somewhat random shifts and sometimes will downshift from 5th to 4th or 3rd when you are cruising. I used infrared temp reader for verification and read OBC for error codes and saw I had the associated code. I don't think the 2-1 is a symptom of temp sensor and even if it is that is also a symptom of other issues.

Have you tried clearing transmission adaptations via INPA?......might help.

LN80962

Imola with Alcantara, but I swapped the alcantara for a mint black nappa interior from a salvage 4.6.

Running boards added and custom Schmiedman x-pipe with Eisenmann exhaust. Sounds evil!