Hey guys, last night i was at a buddies house for a bit and he was in a hurry go to go wal-mart, anyway, when i went to leave, i cranked my truck for a sec and i stopped, did it again and stopped, both before it started, then last time i actually let it start, not sure why i did that either but anyway somwhere between that time and pulling into his alley to let it warm up the light came on, maybe a 1 min time interval.

I drove home with a cold truck, then my high idle cam on, so i let it idle and warm up in my driveway before shutting it down. Ended up having a buddy call me so i drove it to his house instead of parking it for the night. When i got to his house i checked my codes with his reader, got a P1689 and PO236, im used to the 236 so that didn't bother me, but id never had or heard of a P1689, come to find out its P1689 (M) No Communication Between ECM and Injection Pump Module. Data link circuit failure between ECM and fuel injection pump. Low power, engine derated, or engine stops.

Anyway, when i was driving it from one buddies to home, then home to other buddies, i never drove it hard, but i also never felt any of those symptoms. Ive done some research and found out that 99% of the time this is NOT caused by a failing/failed IP, but rather an open ground wire or a failed fuel pump relay. Now, that being said, my grounds are all good, and my FPR is working, because the truck runs.

I cleared the codes, after writing them down, and took it for a pretty good drive. Gt the motor up to operating range and ragged on it to make sure there was no loss of power etc. and that the code didn't come back. Needless to say, i saw 39 lbs of boost and rocketed to 80+ in the matter of about 5-7 sec. in 6th gear from about 35 mph roll. Did this about 3x, and definitly NOT any loss of power.

So now, im debating somewhere in the 3 times i cranked it, within about 5 sec time, something wasn't read on the computer or something turned on and shut off quicker than it should causing a glitch etc., OR our -10 deg weather was just messing with my truck.



Give me your guys consensus on this just to see what your opinions are.

Thanks.

 

I'd say youre fine, probably just the computers getting confused for a split second in the middle of all that cranking. Just watch it a couple days to be sure, hope its not the VP

 

the way it s sounding, its not. like i said, the truck started, and drove normally wheile code was an and after i cleared it.

 

yea i got that same code and it ended up being the fuel relay but it was to late i had already replaced the vp and lift pump befor i figured out about that relay

 

what i dont get, is why it had none of the symptoms that comes with the code??

 

i know what ya mean i think that code follows under a bunch of diff. things

 

oh well still no sign of anything.

 

I've noticed this cold weather sometimes messes with my computer, last winter I threw a bunch of codes, check engine light came on....Cleared codes, truck ran fine, and when it warmed up, nothing else happened. That was at about -20 when the codes popped up.

 

In 2001, you don't have a fuel pump relay. That is sadly taken care of and controlled soley by your pcm, along with a couple of other crucial functions. I also had that 1689 code, but mine did turn out to be the vp. I would be driving down the road, and suddenly it was like I took my foot off the pedal, I could sometimes just clutch down to an idle, the other times I would have to shut off the ignition and turn it back on. One day I had to drive 260 miles of snowy and icy roads to work doing this every 10 to 45 seconds... long drive

 

Mine did the same thing at -25 last week here in wyoming. It cleared itself after 3 good starts and then reset itself again and cleared itself got to love cold weather. I know that electronics do LOL