[Zookscooked]

Hey Guys,

Im having zero luck with my 2002 Automatic m13A non vvti jimny. The forward clutch pack burned itself out and after being off the road for some considerable time now Ive found out that the control unit for the gearbox its self is the actual problem. I rebuilt the gearbox and subsequently have had a mechanic strip it all down and double check everything to make sure we didnt miss anything, he sent the control unit to melbourne twice and its still in limp mode (2nd and sometimes refusing to pick up reverse).

Here's the wanted ad with the particular control module:

viewtopic.php?f=8&t=56617

I guess my question is compatibility with other aisin control units or after market ones, has anyone attempted this before? Id just do the manual swap but Im so far into this car financially at this point its my only option except to part it out or coke can it out of frustration.

Thanks in advance.

[Gwagensteve]

Not aware of any obvious swap, or whether Aisin use some sort of universal control language that means TCC's could be interchanged, likewise, not aware of an aftermarket controller.

Are you absolutely sure that the TCC failed first and not the other way around?

[Zookscooked]

Gwagensteve wrote:

Not aware of any obvious swap, or whether Aisin use some sort of universal control language that means TCC's could be interchanged, likewise, not aware of an aftermarket controller.

Are you absolutely sure that the TCC failed first and not the other way around?

I believe the control unit was packing it in and in turn cooked the transmission according to the mechanic.

[Gwagensteve]

Hmm. They’re a notoriously undersized auto which don’t need much provocation to fail, when temperatures aren’t monitored. I don’t believe the TCC’s are problematic.

[fordem]

I'm not familiar with the transmission used on the Jimnys, but on the older stuff like the 03-72LE or the AW4, the TCU is directly connected to a couple of speed sensors and a number of solenoids that control valves in the valve body - it is possible to shift gears using switches if you know which combination of solenoids selects which gear, my assumption is most units will operate in a similar fashion.

Swapping in a different controller is not going to be a simple task, even when the same base transmission is used, with the same solenoid shift "patterns", the controller shift points will be matched to the engine's power delivery and the controllers are often integrated with the fuel injection controller. I did come across (on the internet) a DIY TCU for an AW4 using a single board computer (a "basic stamp" if I remember correctly), but the control algorithms shifted on road speed, with no consideration of engine speed or load, so very primitive.

I doubt that a failing TCU will "silently" cook a transmission, assuming a reasonably observant driver, the failure would/should be apparent long before transmission damage occurs - if the transmission doesn't shift into first when you're moving off from a standstill, it's very noticeable, if the transmission stays in third instead of shifting to fourth, it's noticeable - prolonged operation will eventually kill the transmission, but, not without the driver noticing.

I went through several months of back & forth with the transmission on one of my cars with an intermittent shift problem, and found that I would pickup on the difference between the expected engine speed for a given road speed long before the TCU would set a check code - when the problem became a "hard" problem I was able to track it down to electrical noise on one of the speed sensor inputs (the so- to-speak origin of the fault is a damaged harness, it was attacked by a dog before I acquired the vehicle).