1996 Volvo D12 wia

ECM is very reliable

only way to damage it - overpressurization when priming goes wrong.

yep, injectors are collected in banks. 1-2-3 and 4-5-6. But if one bank fails - other works

 

have u got wiring diagram?

 

How to check computer off the truck?

First of all - connect grounding and power supply.

Connect diagnostic interface to datalink pins

remove cover, check voltage on flux capacitor terminals (90 v DC)

connect ABS sensor on camshaft terminals

connect relays on injector pins

Move any steel grid to emulate camshaft speed

check for pulses on relays. They click usually/ Puls is 90V, but very fast, so no relay damage

check fault codes, ecm data to be sure processor and memory are ok

 

Thanks Pablo for responding. Actually when I first started working on this truck it wouldn't stay primed. Somebody had already bypassed and removed the prime pump thinking it was the cause for loosing prime. So, like I have done on many trucks, I filled this pressurized cylinder with diesel fuel, loaded up the air pressure, connected it inline with fuel supply and charged it with fuel which immediately primes the fuel. Unfortunately that was before I read your post about not doing that with these 12a's. So what exactly happens when you do that? Could that be the reason why I have no throttle response? I just replaced the tps switch and I checked the wires going back to ecm seemed to be alright.

 

Look at back cover of ECM. If it is not flat, looks lile a frog belly it may be damaged with pressure inside

 

Finally I found truck with D12B engine.

D12A and D12B are different engines, really!

They share mechanics, but ECMs are different. D12B is controlled by VECU via J1939 and really D12B shares ECM with D12C.

 

did you get it going? i have a 1995 volvo wia with ved 12 and had injector problems.

 

did you ever get it going i know the feeling. i have a 95 volvo gmc white with ved 12. very hard to get anyone to work on it. i do most of the repairs myself now. i had injector problems. mc carhty tires in balt. md. they fixed it. they tested the injector harness. when i called volvo here they said they dont have anyone that has the know how to get it fixed.

 

yep, I know, D12A and D12B are like forgoten art.

Volvo wont supporting so old trucks(

 

No doubt still waiting to see what you would charge to make a diagnostic cable for my ved12a. lol can't find a shop with one that works