Auto Gearbox Problems

[allied]

We have had a Bongo for 3 months and we love it, but it has developed a problem. After driving it for 10 - 20 mins it will change down into a low gear and will not change up. The hold light is not on. But flicking on the hold button will resolve the issue, as long as you are not going fast, but it returns to a low gear when the hold button is switched off. It will continue to do this for say 10 mins but will then stop and will be OK. I have contacted a Bongo specialist garage who say it is not the solenoid if the hold light does not come on when the fault happens and dont think it is a throttle position sensor problem. Does anyone have any suggestions? TB

[maxheadroom]

try changing the fluids and clean the filters, see here...

http://www.igmaynard.co.uk/bongo/forum/ ... &hilit=atf

[missfixit70]

As MH said but have you checked the levels properly? Engine warmed & running, brakes on & chocked & range slowly through the gears, Dip the level in P, if it's hard to see a level, try it in D (depress footbrake while doing it).
It could be the TPS I guess if it's changing up when you press the hold button, One of our gearbox experts should be along shortly.

[mikeonb4c]

Is there any possibility the signals from a (chipped) speedo (or tacho? can't remember if this is involved), on which the gearbox relies for control of gear changing, might be involved. Certainly worth eliminating the the simple/cheap things first and there have been incidents of this happening.

[Alacrity]

Very odd fault you have there. Certainly speedo chips have been the cause of many a disaster as far as transmissions are concerned (which is why I never like them) but I have never known a Bongo give trouble in this area (although this wouldn't just give the problem when in the warm up phase).

It appears to be sticking in first possibly & by operating the hold button it is forcing an upshift (hold on in D means 2nd gear pull away & a shift to 3rd only). It could be possibly an odd TPS issue, shift solenoids or road speed sensor to name but a few.

Were it here we would use a signal monitor to 'watch' the solenoid firing order. If they were being powered when they should be to make the shift, & the trans doesn't shift, then you have an internal trans problem. If they are not being powered as they should then the trans is only doing as it is told & you have a external issue such as TPS or speed sensor for example.

[allied]

It seems from the range of suggestions its a trip to the garage. Thanks everyone.

[allied]

I forgot to ask. Can anyone recommend someone in the Bristol area who could sort our problem?

[Cosmic Bus]

http://www.bongospecialists.co.uk/

I will say I have never used them though, but could be worth a try?

[allied]

Turned out that a new throttle position sensor has fixed our problem. We went to ADS Automotive in Bristol. They were very helpful.

[wishmaster]

Good result glad it was an easy fix,some knowledgable people on here dont you think

[mikeonb4c]

Turned out that a new throttle position sensor has fixed our problem. We went to ADS Automotive in Bristol. They were very helpful.

excellent result