Hilux Surf ECT weird problem

I have a 1992 - 2.4L turbo diesel surf with ECU,the problem that 'I had' was
that my transmission locked into 4WD mode with manual Tbar shift only
working in both gear modes.I removed the 89530 35250 ECU checked the
circuits over,plugged it back in and still no fix, I even tried another ECU
computer from another working vehicle with no luck,the ECT diagnostics
would also not run,checked fuses and all was good,the engine ECU showed up a
faulty oxygen sensor,removed the ECT again and left it on the kitchen bench
for 5 weeks while I worked away,came back plugged it in and all was normal
again ???.The vechicle was also parked with the engine towards the top of a
slanted driveway for the 5 weeks,it still drives ok 1 week on.Was the ECT's
memory reset over this time or was it a dodgy brake switch that came good
issue,or what? this still baffles me as to what the real problem was.I did
nothing about the oxygen sensor yet,any input would be appreciated.

Cheers,
Ed.

"bud" <buds[remove]@031316614335> wrote in message
news:47fc2f53$0$13276$5a62ac22@per-qv1-newsreader-01.iinet.net.au...
>I have a 1992 - 2.4L turbo diesel surf with ECU,the problem that 'I had'
>was that my transmission locked into 4WD mode with manual Tbar shift only
>working in both gear modes.I removed the 89530 35250 ECU checked the
>circuits over,plugged it back in and still no fix, I even tried another ECU
>computer from another working vehicle with no luck,the ECT diagnostics
>would also not run,checked fuses and all was good,the engine ECU showed up
>a faulty oxygen sensor,removed the ECT again and left it on the kitchen
>bench for 5 weeks while I worked away,came back plugged it in and all was
>normal again ???.The vechicle was also parked with the engine towards the
>top of a slanted driveway for the 5 weeks,it still drives ok 1 week on.Was
>the ECT's memory reset over this time or was it a dodgy brake switch that
>came good issue,or what? this still baffles me as to what the real problem
>was.I did nothing about the oxygen sensor yet,any input would be
>appreciated.
>
> Cheers,
> Ed.

Unplugging the ECU for the engine or transmission has the same effect as
disconnecting the battery or pulling the ECU's fuse and clears all faults
stored in the memory. My guess is that you will eventually get a check
engine light with the same oxygen sensor fault again.

Check the wiring to the transfer case and front differential to make sure
the wiring is not damaged or disconnected. If that doesn't work, you'll
have to take it to a competent shop for diagnosis.
--

Ray O
(correct punctuation to reply)