Why did you replace the gear selector switch with a used one as opposed to a new one? Are you sure the used one operated perfectly?

Perhaps the fault is inside the gear selector switch.

Obviously to save money when no clear indicator that the gear selector is the main culprit :dunno:. The scanner only indicates to gear selector when the TFP error has begun, prior to this it doesn't.

So if I leave the car overnight. In the morning I can run the car normally. And if I clear the previous gear selector error, it won't show any error for another 20 - 25 mins driving and this is when the TFP error kicks-in.

Couple week ago I was driving it with error was on for around an hour. Stopped for around 5 - 10 mins to pick up some goods and drove back home without any TFP message for the rest of the day (2 separate driving occasion in the same day without an error).

Any clue? thank you in advance.

An update: brought the car to ZF agent in Melbourne for a diagnosis (cost $220 for it). The agent mentioned that transmission has internal mechanical & hydraulic failure. The mechatronics/control unit also faulty causing fault code 5088 (sensor transmission switch). The clutch E indicates 595 mbar - which according to them has reached maximum worn limit, and Cluth C has time adapataion of 60 ms - which caused the erratic shifting on gear 1 - 2.

Their suggestion is to change it with a re-manufactured unit for $6,358.

I called a wrecker in Sunshine and found 2004 3.0D 6 speed transmission for $1800 (with 150K on the odo). Negotiated to $3K for parts + installation cost + fluid with 6 months warranty for parts + labour.

So I'll bring the car to the wrecker for the repalcement. I would also like to pay another $100 to keep my old transmission as the ZF agent told me the solenoids are still good, and I maybe able to use it later on for my other car (E60).