Hi folks
Please can anyone help with a crank no start problem on my (European spec) 2005 Mazda B2500 Turbo diesel?

(I have not managed to read any codes yet as my Mazda OBD adapter plug purchase nightmare is still ongoing (3 weeks and counting...)
Battery good, engine turns over fine, (bit faster than normal). Tried both keys, no weird immobiliser warning flashes, fuses all tested fine (cab and engine bay)

When I turn the key on the glow plug and fuel solenoid circuits do not get powered on.
If I jump the fuel relay those circuits do light up. (and go out after a few seconds suggesting PCM probs ok?)

I have checked the relay command back to the PCM and there is continuity. I have jiggled a few components and plugged/unplugged a few connectors with no signs of life.
It seems like the PCM is deciding not to power on that circuit due a bad/missing input?

Are there any components that are a pre-requisite for that circuit to even get power?

Thanks for any help
cheers
simes

 

Welcome to our North American Ranger forum

Unfortunately, we could never get your Mazda BT50 or the T6 Rangers here, ours were smaller and didn't have diesel engine options after 1986

Google: mazda bt50 forums

 

Thanks Ron
I have a BT50 manual but it shows over 100 pcm pins and mine only has about 60, and the Mazda bravo manual I have shows 20 pins. So mine is somewhere in between.
I was going to sign up to mitchell but as you say, it never went to NA so they dont have it.
Its pretty tough digging through tonnes of Ranger info looking for the odd nugget that relates to B2500s, never mind the fact its diesel...
I'll keep looking I'm sure its something simple to fix (once diagnosed!)
cheers

 

Dont know alot about diesels, myself. Could try some ppl that know diesel engines. I'm sure there are many similarities.

 

Is it OBD2?

 

I'm not sure if its OBD2, it deffo does not have a normal 16 pin socket, it has the Mazda 17 pin. I didnt manage to read any codes obd1 LED flash style, so I am waiting for my adapter lead to arrive so I can plug in an OBD2 scanner and see if I can get any sense out of it.
2005 is just around the changeover era for diesels, by 2006 I think it was standard, but many went around 2004.
I'll hopefully have a more definite answer by the end of the week

 

Quick update
still not managed to read any codes. still dont know if its obd2 or not.

But I have got it started and running well - I jumped the command side of the fuel relay at the pcm pins to ground and powered the fuel cut valve with 12 volts.

I am thinking the root cause is in the immobiliser-fuel pump-pcm comms line, which I am going to be looking at this week. If I manage to fix this I should also get some obd comms, if it is obd2.

 

Final update:
it is OBD2 - but I needed to jump those pins to get the pcm to connect to diagnosis port. There was an anti theft code (too many failed starts probably), which I cleared, no change.
Final diagnosis: fuel cut valve was sticking, new one ordered (not from Mazda they wanted 500 chf (about 500 USD) !!! - for a solenoid valve!). I bought a bosch one on-line for 50.
And the PCM is a little bit broken, I'll send it for repairs to that circuit next week.
(as the main relay powers the crank sensor etc, it can't depend on them on the control side (hat tip scanner danner), so the only thing stopping it from grounding that circuit must be internal damage.)

Thanks for all your help
cheers

 

thanks for the update. Hopefully its running like new again soon.