Bongo Fury

V6 auto 2001

I have a flashing hold light when turning the ignition on but not while driving. It's a simple one flash on and off repeating.

It seems I do not have a live feed to the diagnostic box. I have no voltage when connecting the D (positive) and E (ground) terminals. Should that read 12v with the ignition on? What's the best way to fault find for this?

Thank you in advance!

Any ideas where I should start with this investigation? Firstly, I'd like to confirm the diagnostic port is receiving power.

Thanks

Are you sure your selecting the right pins, the box is mounted upside down compared to the other vehicles which is where the diagrams come from. The error code flashes won't start until you put the links in place, prior to that its just the on/off flash.
http://www.philmcfadden.co.uk/MazdaDiagnosticBox.htm The fuse is the far left 15Amp Blue middle row, which also supplies lots of other circuits around the engine itself.

I have tried a combination of wires; an led with a resistor and without, a paperclip jumper and an electronics kit jumper wire. I am not getting any flash, with or without ignition.

The hold light on the dash still flashes on and off in ignition position, but not while engine running. I wonder if this is a fault notice in itself, of the diagnosis port?

Make sure you have the LED connected the right way around, they are polarity sensitive or use a low wattage filament lamp!

Just a thought you don't have a flat LB do you ? The most common error is loss of backup supply, this will mean it spots the error before the engine starts and hence starts flashing straight away.

Both batteries are topped up with a solar controller. The controller and the PMS3 are showing full batteries. I've had no other signs of battery issues.

I've tried all sorts of combinations of wires and tiny filament bulbs and leds. I just don't think there's a signal coming into the diagnostic port.

If I have to trace continuity from the port, where does it all go back to?

The wiring goes back to the relevant computer, PCM, TCM, ABS etc.
Make sure you do have the diagram correctly oriented, its upside down in the Bongo. also make sure your linking the correct pins its an automatic not a Manual gearbox for most people!

Here's my configuration for connections

Try using the TAT and FAT pins respectively (rather than TEN and FEN) as your probably an automatic gear box ?

Yes, it's an auto.

I thought the TEN and FEN were for engine codes and TAT and FAT were for auto box codes?

Anyway, no lights with either configuration.

Some of the ECU's are all in one, hence there isn't a separate Engine computer from the overall ECU which includes the Auto box computer. Its not clear from either the mech diagrams or the electrical diagrams which versions have which.

I went for a drive today and the hold light miraculously started flashing codes at me! I had left the jumper cables and led connected from my last attempts at fault code reading.

Anyway, the code I have is:

Long x 1, Short x 1
Long x 1, Short x 6
Long x 1
Long x 1, Short x 1
Repeat

Is this code 1601? Before I reset the codes, is there anything I should check first?

P1601 MAZDA code possible causes;
Faulty Engine Control Module (ECM)
Engine Control Module (ECM) harness is open or shorted
Engine Control Module (ECM) circuit poor electrical connection

or another site says;
Mazda:
Powertrain Control Module Communication Line to TCM Error

Its a later version so yes its probably sending the 4-digit codes out.

Have you had a flat leisure battery at all or disconnected the SB if you don't have a LB ?
Is this since you blew the fuse, losing power to the ECU could well generate that code as well, they normally reset themselves when the error is fixed or disappears !

No nothing specific to do with the battery. I've had solar for a couple of years and both batteries have been pretty much 100% all along.

I recently put in a new style low coolant alarm and that would have involved some soldering. The fuse would have been out but I don't recall disconnecting the batteries.

The poor or faulty connection could explain the difficulty of getting the codes to display? Would it be best to do a reset and see if it comes back?

Depends which fuse, just realised your not the one that blew the engine fuse that powers the diagnostic socket - that was someone else!
If you disconnected the top row left fuse (or where ever that goes on the swap loom to the LB) then that disconnects the bcakup supply to the ECU and will cause an error light.