P1689 after new VP44

**Netraracer1217** · 03-30-2013

Alright guys heres my problem. My truck was throwing the po216 code so i replaced the pump and it went away. I thought all was good untill it threw the p1689 code (communication failure between ecm and fpcm). The truck will just randomly die, dead pedal, sound like its sorta backfiring out the exhaust, haze a constant blue, not shift from first gear, not rev past 1400 rpm or it will run good with the code. Then somedays the code goes away and it runs great. My question is, is my new VP44 defective? Or does this sound like a wiring or ecm issue? Keep in mind this started after the new pump was installed and this code was never present before. Thanks in advance for some input!

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**Diesel Dawgs Performance** · 03-30-2013

Sounds like a bad ECM.... whos VP44?

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**Polaraco** · 03-30-2013

check the crank sensor. Take it out and look for cracks. Try cleaning the face off first. Cam sensors were known to go bad in those early models too. Losing a cam sensor after startup could be confusing the ECM. Check them both

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**Netraracer1217** · 03-31-2013

The VP is from thoroughbred diesel. Ill take a look at the crank and cam senors. The crank sensor isnt even 2 months old yet. If it does turn out to be a ECM are they dealer only or can i buy one online somewhere?

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