ECU wiring connections

[Cynog]

I've recently been crazy enough to take on a Bongo which has been VOR for several years following an engine cutting out problem which gradually grew in frequency until it was impractical to drive.
It's a 2.5td AFT 4WD made in November 1999. It starts without problem, but after say 8 minutes of idling the coil lamp starts to flash and a few minutes later the engine cuts out, unless the engine cover is open when it continues to run at least long enough to bleed the cooling system.
The coil lamp flashes uniformly unless I attempt to read the ECU error codes using an earth jumper and a bulb, when both the coil lamp and the bulb flash together, showing codes 11, 12, 14, and 18 (!) if I'm understanding it correctly (definitely not 38). Faults with the engine bay sensor (11) and scavenger system (14) make sense, and the throttle sensor (12) I will need to look at. As the hold lamp flashes occasionally it seems there's probably an intermittent fault there.
My first question is, does fault code 18 exist and if so, what is it?
The second problem is that the ECU terminals don't correspond with the diagram in the manual. My Bongo has 27 wires connected, but spread around 38 terminals, so it's tricky checking for continuity. Does anyone know where I can find details of the later ECU and wiring colours please?
My third problem is that disconnecting both battery earth leads and operating the brake pedal doesn't get rid of the error codes (or the flashing lamps). I have to wait until the engine is fully cold to start again.
The vehicle has a very nice camper conversion and it will be a great Bongo again once I've sorted the engine, brakes and some tin worm. Any advice would be very gratefully received.

[willow2u]

I would be curious as to why the engine runs longer with engine cover open

[g8dhe]

Where are you getting the ECU pinouts from ?
The wiring diagrams I have put on-line are only up to September 1999 so they could have changed in the later versions;
http://www.g8dhe.net/bwm
You will need Flash installed and enabled for the site within the browser.

[rita]

I would be curious as to why the engine runs longer with engine cover open

Thats a good point, there might be a wee clue here.......


Faults with the engine bay sensor (11) and scavenger system (14) make sense,.

[Cynog]

Thanks for your replies. I'm assuming the problem, or at least a part of it, is a faulty scavenging system and having the engine cover open is easing this. As Rita notes, this ties in with the codes.
I've checked the resistances across the engine bay temperature sensor and they are good, as is the 5v supply to it. I've also checked the coolant temperature sensor resistances and they are good too. Disconnecting the coolant sensor causes all radiator fans to run at full speed, so the coolant system seems likely to be okay, although I note the fault arises before the radiator fans have cut in.
I now want to check for a break or a short in the wiring of the scavenging system and without a wiring diagram or details of the ECU connections and colour codes I'm floundering.
Does anyone know whether the reluctance to clear the codes is likely to be down to an error in my method (it seems simple enough) or is it a common experience?

[Cynog]

And thanks Geoff. Yes, the ECU I'm dealing with is rather different, though it has occurred to me that by studying the earlier diagrams I can probably get a much better idea of how Mazda wired the control systems than I have so far!
Thank you for all your work on these and I'll see what I can learn this weekend.

[Cynog]

Just an update on this problem and a Thank you to all who responded.
I've subsequently made sense of the fault codes. I hadn't realised that the 4-number codes give a long flash to denote the start of each digit in the code, hence I missed the zeros!
When it dawned on me, I realised I had a pesky EGR fault - 0400 and 1228. As blanking gaskets had been fitted at each end of the EGR pipe, I removed and cleaned out both valves with oven cleaner, checked for movement when a vacuum is applied to each, cleaned the ports and pipe, then refitted everything.
I've just run the engine on the drive for an hour without any flashing lights! My next job is to sort out the ABS fault showing, a limited amount of rust underneath, and book an MOT. Then I'll discover whether I have cured the EGR fault properly.
Btw I've seen a YouTube video suggesting EGR systems can be cleaned by spraying oven cleaner into the turbo. I strongly recommend not doing this. On worn engines, the ones likely to have EGR problems, the carbon around the top of the pistons will be acting as an extra piston ring. Feeding anything that clears carbon effectively through the engine may shift the carbon out of the EGR but will very likely do the same to the combustion chambers.

[Gandalf The White]

Hi there.

I had a longstanding problems with our 2002 Diesel Bongo with the dreaded going into limp mode and glow plug light flashing once engine was warm and sat in traffic. I cleared all the old fault codes and found the two fault codes being displayed were P0400 and P1228. Spent hours researching this trawling for answers through the forums, FB groups and it's also well detailed on the Wastegate Actuator factsheet in the members section. It's obvious people have spent hours on this, but nothing seems to give a permanent guaranteed long term fix. After much head scratching I discovered Mark at The Bongo Master in Leicestershire, really good, decent, honest bloke, who knows Bongos inside and out, he has great reviews from all his customers. Mark immediately knew what the problem was. It's a known issue with later Bongos, due to combination of a change of turbo design and poorer quality grade diesel in the UK. Mark charges £600 to retrofit an older turbo from an earlier model and changes the relevant ducting and piping to go with it. The van then ran as sweet as a nut, with no loss in performance at all. Just thought I'd share, as it could save somebody alot of time, money and hassle in the future.

https://www.thebongomaster.co.uk/

[Onegoldenearth]

I've had this issue. Managed to fix it by having the turbo overhauled. The company I used just stripped the turbo cleaned it and re-assembled with a rebalance. Cost around £200.