EBP codes then no commun PCM TCM

robp823 · November 24, 2008

06 e350 ambulance came in with mil on. Pulled a p0471 ebp sensor range performance and p0473 ebp sensor high input.Started it up pulled up pids and watched the ebp pid and the signal was erractic up and down. So i brought it in the shop pulled the doggy door,popped the connector off and found a piece of plastic on the connector was bent over,also pulled the sensor to check it out it looked ok.So going through ppt for both dtc's which is ppt x.It says the unplug the sensor and run self test again to see if you come up with p0472.Well i did that didnt come up with p0472 but didnt come up with a pcm or tcm either.ids wont reconnect its asking me to manually connect its acting like a blank pcm. truck wont start and im stumped. When i unplugged the sensor could i have possibly shorted somthing in the harness and fried the pcm??? any help always appreciated

Bruce Amacker · November 25, 2008

The harness or EBP connector is probably screwed up and shorted VREF to Sensor Return (ground). If you short VREF on a three wire sensor to ground, the PCM usually goes into sleep mode and will not communicate. I'd check not only that VREF, but any other VREF circuits- sometimes there's 2-3 separate VREFs. Check them all KOEO and make sure they're 4.9v to 5.1v. Once you correct the short circuit, the PCM wakes up and there's no long term damage done.

If you find a problem, replace the EBP and connector pigtail. It's the same PN as the ICP connector,

PN 5C3Z-12224-A $55.34

IH 2501105C1 $12.10

Napa EC89 $15.99

Good Luck!

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robp823 · November 25, 2008

o boy this should be fun would the easiest way to do this be to pull the pin out of the connector at the pcm for the vref to the ebp that way i could at least wake the pcm up

Bruce Amacker · November 25, 2008

o boy this should be fun would the easiest way to do this be to pull the pin out of the connector at the pcm for the vref to the ebp that way i could at least wake the pcm up

If you ask ten techs, you'll get ten different procedures. What I'd do is examine the EBP connector, or cut it off, and see if the PCM will talk. if not, I'd put a breakout box on the PCM (not easy on an E-van, but possible) and see what's alive and what's not with a DVOM.

105-R0107 Rotunda BOB adapter adapts your old 104 pin BOB to the new 122 pin setup found on the 6.0.

Good Luck!

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mchan68 · November 25, 2008

o boy this should be fun would the easiest way to do this be to pull the pin out of the connector at the pcm for the vref to the ebp that way i could at least wake the pcm up

The V-ref circuit for the EBP is the brown with white stripe coloured wire. It is spliced into the V-ref circuits for the EGR valve and the ICP sensor if this helps.