hold light flashing

[rocketeeer]

Hold light flashing and auto gearbox stuck in safe mode (3rd only).
Could be the speed sensor as the speedo is going nuts: needle wobbling all over the place.

Anyone know where I can get the transmission fault codes for a 2003 auto gearbox 4wd Bongo? (bongofury datasheet only has codes for a pre-1997 bongo).

Thanks for any assistance you can give; only bought it 4 days ago and gutted it's broken down! Now trying to find a gearbox specialist in central Scotland.

[teenmal]

Hi,is your vehicle under guarantee??

This firm is very good but can be quite expensive.Where are you based.

http://www.mackie-transmission.com/

[Simon Jones]

Are you sure the codes are not the same? I'm not sure that the gearbox is that different between those years.

[briwy]

Ours did the same earlier this year in the snow.
It cleared itself and no problems since over a couple of thousand miles.
I was ploughing through deep snow and the connections face forward so could gather nasties.
I think that snow/water/crap built up underneath and forced it's way into the electrical connections on the gearbox.
I took them off, gave then a good dose of WD40 and like I said no more problems. Worth a try.

[rocketeeer]

Mackie's transmissions, thanks. Have you used them before? can they handle Bongos?
I am based near Glasgow.

[rocketeeer]

Auto gearbox specialist in Glasgow says the speedo is causing the hold light to come on: transmission computer is not getting the correct speed input. This makes sense as the speedo needle is currently going nuts, wobbling all over the dial.
How is this wired? Presumably there's a speed sensor on the transmission somewhere (the 'sender') which is wired to a 'receiver' somewhere behind the (chipped to MPH) speedo?
Where, in the circuit, does the transmission computer get its signal from?

How do you electrically test the output of the speed sensor? (rather not replace it unless necessary as is expensive!)

Any help greatly appreciated!

[Northern Bongolow]

20h10 maybe.
http://lushprojects.com/bongopartsmk2/c ... mgno=.html

[mikeWalsall]

It as been mentioned before that an after market MPH speedo converter chip can give auto gear box problems ..

[g8dhe]

I doubt that the basic pickup points will have changed much no matter what year the vehicle is, only once your inside the ECU will things be different so a quick look at the older wiring diagrams will show you what to look for and most likely even the same connectors and colours;

The speedo is the rectangle on the left of the display board, with the pickups from C1-03, the output to the ECU is on diagram link 19.
Connectors are shown at the bottom of the page and colour codes can be looked up by clicking the

[rocketeeer]

Okay, let me see if I've got it:
Speedo sensor is called C2-03 on the wiring diagram of the instrument panel (page 57, as given in Spherical Vision's posting of 'Re: Is this a faulty ECU?' Posted: Fri Mar 16, 2012 1:37 pm, search on the keywords 'There are TWO speed sensors one feeds the display')

This then becomes C1-03 on the wiring diagram of the instrument panel (page 50) in Spherical Vision's posting given above.

C1-03 (which appears to be two inputs???) goes to the rectangle with Japanese writing that is the speedo, which then goes to the ECU via connection 19.

Can I ask which output goes to the transmission computer?

Right, I'll email this info to my mechanic Davy at Caledonian transmissions. He knows his auto gearboxes, but is struggling with the speedo as he's never seen a Bongo before.
We've now established that the speedo isn't chipped: found the guy that imported it and he simply put a new faceplate on the speedo.

Davy disconnected all speed sensors but the speedo is still going crazy, so we think that the speedo unit is faulty.
I've got him talking to Adam at Bongobits.com as we need advice from a Bongo expert on this. Can anyone suggest someone else he could 'phone as well?

Thanks for everyone's advice. I'm afraid I'm no mechanic, I just wanted a nice campervan, and made the costly mistake of buying privately!

[rocketeeer]

Ah, I see that sensor C1-03 (page 51) is relabelled C2-03 on page 57 (oops?)

[rocketeeer]

Got it, page 57 is for a different variant of the Bongo, mine's WL-T

[Northern Bongolow]

20h10 maybe.
http://lushprojects.com/bongopartsmk2/c ... mgno=.html

sorry about posting the wrong link above.
it should have been this one. part 20H10
http://lushprojects.com/bongopartsmk2/c ... mgno=.html

try removing 20H10 from its one bolt mounting. i found one today that was drowning in diesel that was leaking from the fuel pump front seal and filling up the sensor cavity, this was making the speedo dance and sometimes not work at all.

[g8dhe]

Yup that's about right its the wire on pin 1D of the C1-01 connector on the Instrument panel that goes off to the ECU/TCM and a load of other places! The ECU and TCM are one and the same on the WL-T and is labelled PCM (just to confuse things!). The TCM only exists as a separate item on the petrol models.

[rocketeeer]

Thanks guys, that's great info!
Not sure what sensor 20H10 is bolted to (picture wasn't clear), but if we find it, we'll check it out. Is it the speedo sensor on the back of the transfer box, or something else?

Now found an additional fault! The transmission fluid temperature sensor (TFT) is triggering the hold light flashing as well. We've only discovered it once completely disconnecting the speedo. It's coming on mere seconds after starting the engine, so the mechanic doesn't think it's actually a high fluid temperature. Can you tell us where this sensor is located (model WL-T: 2.5 litre diesel automatic).