V6 Gearbox SOS

[Ian]

We have received this cry for help. I have searched the forum archives but can't find anything similar? Can anyone help Roger?

I hope you or your members may be able to assist us. We have a garage in the village of Melbourne near Derby and Donington Park racing circuit, and we are specialist in auto electrical and diagnostic work. We have a 1999 2.5 V6 petrol Auto Bongo belonging to a customer that is driving me mad!! In essence the vehicle will not go in to 4th gear when being driven. The gearbox has been to a specialist and is all OK, and I have checked all the feeds and outputs to and from the transmission control unit ECU and as far as I can tell everything signal wise is there. I know that the gearbox oil temperature has to be above a certain temperature before the box will go in to 4th, and the resistance checks on this show the sensor to be giving the correct output. If we drive the vehicle and activate the appropriate solenoid for 4th, the car then goes in to 4th and drives fine, so the ECU is not sending the signal to the solenoid to energise and I don’t know why. We have tried another gearbox ECU to no avail, and while I have been able to get wiring diagrams for it
off the Bongo Fury site, a lot of the information is in Japanese that I am unable to read. So as far as I can tell, temp sensors, speed sensors, gear selector lever, fused inputs and all the earths are all OK, so I would like to ask 2 things please:

1. Has anyone had this problem and found the solution, or has all the wiring and function manuals in English

2. Does anyone near us (postcode DE73 8JB) have one of the that they would be prepared to drop down to us for a couple of hours or so in order that we could collect some comparison data from their vehicle so that we can check what we have against a good known vehicle? (Happy to pay someone for their time and mileage)

The owner is obviously very frustrated that we have not been able to find the problem, and to be honest I don’t let anything beat me, however the difficulty getting in depth information, and the fact I have no actual data to compare what I have from this one has now brought me to halt on this one. Yours and your members assistance would be greatly appreciated.

By the way we are also a Terraclean Service Centre, and as an incentive, if someone is prepared to lend me their vehicle to check the data for 24 hours, then I would carry out a free Terraclean for them, and lend them our loan car whilst I have their Bongo.

I hope you can assist, and look forward to hearing from you.
Roger Frazer - Partner
Autotech Garage Services
Castle Lane Industrial Estate
Melbourne
Derby DE73 8JB

I have also asked for volunteers in the Midlands section.