Bongo Fury

Progress today:

- flashes are definitely in straight (single digit) groups of six, so the most likely indication is seemingly the driver's side airbag - of course, including its power supply, connectors (in particular, the steering wheel clock spring connector) or wiring, as well as the airbag module itself. Could also be a computer glitch, I suppose.

- the two fuses indicated by Geoff's diagrams are intact, as are all fuses in the cabin fusebox.

- the horn works, no problem.

- have tried the first two possibilities here http://www.ehow.co.uk/how_7553635_do-ai ... b3000.html, without success. Will try stage 3, disconnecting the negative battery terminal (why the negative?), tomorrow

If that doesn't work,I'll do what I can to check all connections for a high resistance (damp?) or an open circuit. After that, it's got to be either the airbag module or a computer glitch, and I reckon that would mean a trip to a Mazda dealer - hoping they might have online access to relevant Bongo info, whereas a.n.o. garage will not.

Ron Miel wrote:... disconnecting the negative battery terminal (why the negative?),

Its normal to disconnect the -ve terminal first, because then when you drop or pull on the metal spanner on the +Ve terminal and touch the chassis of the vehicle you don't get a big spark!
Obviously when your disconnecting the -ve terminal to start with it doesn't matter if the spanner touches the chassis as its already at the same voltage.
Likewise when you reconnect or use jumper cables, connect the +ve first before connecting the -ve then any mistakes other than bridging both terminals of the battery won't cause a problem.

g8dhe wrote:

Ron Miel wrote:... disconnecting the negative battery terminal (why the negative?),

Its normal to disconnect the -ve terminal first, because then when you drop or pull on the metal spanner on the +Ve terminal and touch the chassis of the vehicle you don't get a big spark!
Obviously when your disconnecting the -ve terminal to start with it doesn't matter if the spanner touches the chassis as its already at the same voltage.
Likewise when you reconnect or use jumper cables, connect the +ve first before connecting the -ve then any mistakes other than bridging both terminals of the battery won't cause a problem.

Understood Geoff and thanks for the reminder. I admit that to isolate but not remove the Bongo battery, I don't usually diss the negative though, as the positive's easier to get at and I eliminate the shorting risk by using a small spanner far too short to reach between the positive terminal and any grounded part. Meanwhile, confess I had forgotten why!

In any case, all of a rush, I carelessly expressed my question incompletely - although I see that it matches what the eHow item I linked to said, i.e., just diss at the negative battery terminal. There were two web references to that Mazda B3000 test sequence though, and the other one said to disconnect the battery negative by unbolting the grounded cable from the vehicle chassis. I really meant to say, why unbolt the negative cable to chassis connection - unless just to clean up the connection (but it didn't say so, and I would start with a resistance measurement anyway).

Ron Miel wrote:

g8dhe wrote:

Ron Miel wrote:... disconnecting the negative battery terminal (why the negative?),

Its normal to disconnect the -ve terminal first, because then when you drop or pull on the metal spanner on the +Ve terminal and touch the chassis of the vehicle you don't get a big spark!
Obviously when your disconnecting the -ve terminal to start with it doesn't matter if the spanner touches the chassis as its already at the same voltage.
Likewise when you reconnect or use jumper cables, connect the +ve first before connecting the -ve then any mistakes other than bridging both terminals of the battery won't cause a problem.

Understood Geoff and thanks for the reminder. I admit that to isolate but not remove the Bongo battery, I don't usually diss the negative though, as the positive's easier to get at and I eliminate the shorting risk by using a small spanner far too short to reach between the positive terminal and any grounded part. Meanwhile, confess I had forgotten why!

In any case, all of a rush, I carelessly expressed my question incompletely - although I see that it matches what the eHow item I linked to said, i.e., just diss at the negative battery terminal. There were two web references to that Mazda B3000 test sequence though, and the other one said to disconnect the battery negative by unbolting the grounded cable from the vehicle chassis. I really meant to say, why unbolt the negative cable to chassis connection - unless just to clean up the connection (but it didn't say so, and I would start with a resistance measurement anyway).

Oh, and more to the point, I had already tried to reset the SRS system by two long main battery disconnects - albeit, with the positive cable removed. Same difference though (as I was also trying to say!), although I'll try it again this afternoon, in case a damp weather-caused high resistance somewhere has since dried out and it will now reset. Otherwise, I'll flog through all the connector tests above but I increasingly feel I might be looking at a Mazda dealer replacement of the bag, and a scanned system reset - assuming, that is, that a UK dealer will have OBD tools for a Bongo? Anybody been there?

Upto 1999 the SRS didn't have a connection to the OBD connector, not sure if the later versions do ?

g8dhe wrote:Upto 1999 the SRS didn't have a connection to the OBD connector, not sure if the later versions do ?

No, later ones are also standalone systems with a separate management computer behind the dash. Haven't yet crawled under there to check for an OBD link from, or a direct diagnostics output connector on, it but as the V6 OBD info in neither the diagnostics fact sheet, nor the referenced site http://www.iequus.com/Dtc, includes SRS codes, I guess the only diagnotics are those shown by the warning light. If so, the re-set methods I've been trying are also probably the right ones - i.e., no OBD2 style re-set routines, but in which case there's still a fault somewhere.

Just got back from talking to a helpful and knowlegeable technician at our local Mazda dealer (although not allowed to be helpful enough to work on it - so, it's still down to yours truly); he thought I'm on the right track and suggested I take out the airbag and test continuity back from there. Also suggested that a quick test on overall continuity and computer functionality would be to replace the bag with a resistor of about the right value, "usually around 1.6 ohms", and then try again for a reset. Don't suppose anybody's got a defo figure for the resistance of a Bongo driver's airbag? Do not test with an ohmeter or other "live" test instrument - that can fire the bag!!).

Might have to leave alone for a day or two now but will report progress. Seems to be a rare Bongo fault, BTW, as I can find almost no forum SRS diagnostic/re-set topics.

Ron Miel wrote:

g8dhe wrote:Upto 1999 the SRS didn't have a connection to the OBD connector, not sure if the later versions do ?

No, later ones are also standalone systems with a separate management computer behind the dash. Haven't yet crawled under there to check for an OBD link from, or a direct diagnostics output connector on, it but as the V6 OBD info in neither the diagnostics fact sheet, nor the referenced site http://www.iequus.com/Dtc, includes SRS codes, I guess the only diagnotics are those shown by the warning light. If so, the re-set methods I've been trying are also probably the right ones - i.e., no OBD2 style re-set routines, but in which case there's still a fault somewhere.

Just got back from talking to a helpful and knowlegeable technician at our local Mazda dealer (although not allowed to be helpful enough to work on it - so, it's still down to yours truly); he thought I'm on the right track and suggested I take out the airbag and test continuity back from there. Also suggested that a quick test on overall continuity and computer functionality would be to replace the bag with a resistor of about the right value, "usually around 1.6 ohms", and then try again for a reset. Don't suppose anybody's got a defo figure for the resistance of a Bongo driver's airbag? Do not test with an ohmeter or other "live" test instrument - that can fire the bag!!).

Might have to leave alone for a day or two now but will report progress. Seems to be a rare Bongo fault, BTW, as I can find almost no forum SRS diagnostic/re-set topics.

Just got further useful advice from very friendly guy here http://www.dashwarninglights.co.uk/ :

1.) All Mazda SRS lamps, including those on current OBD2 equipped models, auto-reset once the fault is cleared.

2.) High resistance at a steering column clock spring connector is still the most likely cause. H/R there will trip the SRS computer but is often not high enough to stop the horn working.

3.) The other usual suspect is an SRS seat occupancy sensor but I had already checked that, and our Bongo doesn't have one, driver's side at least - only a seat belt connected sensor. Seat belt pre-tensioner sensors are also included in most Euro SRS diagnostics, therefore although I suspect that's a bit sophisticated for the apparently simple SRS diagnostics in a Bongo, I'll also have to check for that, if the clock spring does not prove to be the cause.

4.) He thought the airbag resistance was most likely to be 1.8, not 1.6 ohms - fortunately, I bought both 1.6 and 1.8 ohm resistors yesterday at Maplin

Back on the case tomorrow or Wednesday, depending on progress meanwhile on a lot of neglected paper work

EDIT: BTW, I'm working on the assumption that our (December 2000 production) V6 is most likely to have similar simplified SRS diagnostics to the post-99 Miata (MX-5), as listed at the bottom of Paul's post here http://www.igmaynard.co.uk/bongo/forum/ ... f8#p470520. As Geoff said, that also stacks up with numerous other online forum and other references to Code 6 (6 flashes), as indicating a driver's side airbag (system) problem.

g8dhe wrote:Check the cable connecting the bag to the system under the steering wheel cover, there isn't "much" to the testing system itself, it only checks to see if the bag is present, and if not flags the lamp.
There are two connectors for the drivers bag S-03 and S-04;

located behind the bag and at the base of the steering wheee;

Looks like I've been lucky Just got back on this job today, due to to other stuff meanwhile, and Bongo therefore grounded until now.

Had checked S-03 and S-04 with some fairly vigorous wiggling earlier, with no result. Today, before finally buying a clockspring connector (if not a wiring harness connector, it's the clockspring or the bag, and the only way to check the bag is to detonate it!), I pulled them apart and applied contact cleaner. BINGO! We seem to be in business!

Thanks to Geoff and Paul for invaluable inputs - Bongo Fury proves its great worth again

Have also done lots of online research into airbags, airbag control systems, airbag service life (there's a lot of smoke and mirrors going on out there!), airbag removal issues, and so on, so if anybody comes up with questions they can't find answers to, feel free to PM - I might be able to point them in the right direction.

It seems pretty certain that new shape (post Sept '99 production) Bongos at least, share their SRS computers and airbag diagnostics, with post '99 Miata's (Japanese home market MX5's) - diagnostics as set out in Paul's post above.

Glad to see you sorted have you managed to eat all that marmalade yet?

dunslair wrote:Glad to see you sorted have you managed to eat all that marmalade yet?

No but if I eat much more I won't fit behind the steering wheel and airbags will be irrelevant

Ron Miel wrote:

dunslair wrote:Glad to see you sorted have you managed to eat all that marmalade yet?

No but if I eat much more I won't fit behind the steering wheel and airbags will be irrelevant