Td5 clunky tranny / p38 valve body?

[mpwdhc]

I have a td5 when warm the tranny does a terrible clunk on downshift from 3-2 and 2- 1. The nanocom occasionally shows a p1884 flag_tl_mes. I feel this could be a valve body issue and could I swap the current valve body for a gems 4.6 p38 ? Many thanks

[shack]

I have a td5 when warm the tranny does a terrible clunk on downshift from 3-2 and 2- 1. The nanocom occasionally shows a p1884 flag_tl_mes. I feel this could be a valve body issue and could I swap the current valve body for a gems 4.6 p38 ? Many thanksCan't comment on the p38 valve body, but that error code is basically invalid engine torque, that can give harsh changes and other issues.

I'd be checking for oil at the ECU connectors.

[mpwdhc]

Thanks for the advice. So far have checked the ecu for oil. None. Changed the Maf. During driving the clunk was occurring the no code too and seems to occur when the tranny has warmed up.

[shack]

Thanks for the advice. So far have checked the ecu for oil. None. Changed the Maf. During driving the clunk was occurring the no code too and seems to occur when the tranny has warmed up.You are possibly already aware, but the loom for the auto can chafe through where it runs over the top of the box... Maybe worth checking, but it's not easy.

I removed the gear selector and riveted in plate that covers the auto inside the cabin.

The fault code you are getting is a communication error between the TCU and the ECU on the CAN wires.

There are a few possible reasons, oil is one and dodgy wiring is another.

You could definitely have a mechanical problem though, but the fault code really is a comms error. It's unusual there are no other CAN faults though, but I have had that fault with no other CAN faults, it was oil in the ECU plugs.

[Tins]

James, could the infamous A/C drain issue cause this? XYZ switch?

Old thread here (https://www.aulro.com/afvb/electronic-diagnostic-systems/204634-fault-code-p1884.html) may have some info, dunno. I join threads like this one in order to learn.

[shack]

James, could the infamous A/C drain issue cause this? XYZ switch?

Old thread here (https://www.aulro.com/afvb/electronic-diagnostic-systems/204634-fault-code-p1884.html) may have some info, dunno. I join threads like this one in order to learn.It's unlikely.

The XYZ switch (position switch) has fairly good error checking routines on a TD5, not as thorough as on some other versions of the 4hp22 software, but still fine.

With pretty much ANY position switch fault, M & S will come on and the trans will default to 3rd or 4th gear, no adaptions for pressure or otherwise.


So you won't get harsh up or down shifts, as it doesn't shift!