03 f-350 no crank/no communication

robp823 · February 6, 2009

Ok....This is more like a question of why this would happen. I already fixed the vehicle with hotline help. The truck came in on the hook for no crank no start.Checked all fuses and relays everything was good. Batteries were fully charged, inertia switch wasnt popped,inspected all pcm and ficm connecters and all fully seated, no signs of wire chafes.IDS would not communicate with pcm it was like it was blank.So i contacted hot line and they said to start unplugging all sensor like MAF,EGR,ICP etc....to see if i had a short to v-ref.So i did and when i went to inspect the EBP the sensor was broke in half and barely held together.As soon as i wiggled it the truck fired right up.Now since 03's dont even use the EBP i just broke it right off and moved the connector out of the way for now.My question is if its shorts to v-ref why wouldnt it allow the truck to start or communicate with ids???? Saftey feature for pcm????Might seem like a stupid question but im still learning everyday. Any help always appreciated.

mchan68 · February 6, 2009

EBP, EGR and ICP all share the same v-ref circuit if I'm not mistaken. Take a look at your wiring diagram.

Bruce Amacker · February 6, 2009

Even with the 06E17 inferred EBP flash, the EBP sensor is still powered and completely alive, but the PCM disregards its signal. If you short it to ground, the PCM goes to sleep- no start, no communication with the scan tool.

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robp823 · February 6, 2009

ok so that is a saftey feature of the pcm if you short to vref?

Bruce Amacker · February 6, 2009

No, it's just an operational glitch that applies to many mfr's and many VREF circuits. IIRC, on later trucks like '05 Fords they split some of the VREF's so the PCM can still be alive with some VREF's grounded.

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robp823 · February 6, 2009

thanks bruce so should i put a new ebp on this or just leave it unplugged?

Mekanik · February 6, 2009

Well I'm not bruce. Posted Image

But if you just leave it unplugged or better yet, cut the vref wire from the connector and then put some heat shrink around it so it cannot possibly short to ground I think you would be fine. It just seems like a waste of money to put a sensor on this truck that the PCM does not even look at.

I actually know a tech that always leave the EBP disconnected on trucks with inferred EBPs.

robp823 · February 6, 2009

thats what i was thinking as well Thanks MEKANIK! ahahahah

Keith Browning · February 6, 2009

But EP is still a valid PID and is useful for diagnosis. Disabling it or cutting it off seems unnecessary to me... but, since Ford disabled it I recall they won't pay to replace it. So, what do you do if the sensor shorts and takes doen that VREF circuit? It's rare but I do recall hearing of it happening.

Bruce Amacker · February 6, 2009

Well I'm not bruce.

But if you just leave it unplugged or better yet, cut the vref wire from the connector and then put some heat shrink around it so it cannot possibly short to ground I think you would be fine. It just seems like a waste of money to put a sensor on this truck that the PCM does not even look at.

I actually know a tech that always leave the EBP disconnected on trucks with inferred EBPs.

Either way would be fine, it's a matter of personal preference. I'd probably find a used EBP and install it just to keep an OE appearance. You never know when FMC is gonna recall all of these and reverse the 06E17 program..........!

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robp823 · February 6, 2009

hmmmmmm...... well all very good points but its not under warranty anymore and the guy just dumped over 2000.00 on it so i just zipped tied the connector up and taped it off hopefully he wont have anymore problems. I explained to him too so if it does happen again he will no whats going on.He was understanding. Good customer