A couple of weeks ago Van was flipping out and stalling ......did not have my scanner with me so ....I assumed it was the IDM... I changed it with one of my spares...along with a spare PCM ..was Ok for a little bit.. would still stall but would start back up again ...would show PO603 and PO500 codes. I decided to send the PCM out to get repaired.....they called me a week later and said it was fine ( SIA Electronics). so I checked most of the connections with the exception of the PCM to IDM connections ... Now truck dies after running for a few seconds, and the wait to start light and Check engine light Flickers like before and I get same codes P0603 and P0500 . I fixed a few sketchy wires that I could see I repaired replaced one Battery connector ...and cleaned connections them and re-assembled with Diielectric grease . Tomorrow I will check the fuses inside the Truck as I have replaced the Fuses and Relays in the engine bay ....according to the manual it is the IDM relay and and 60 Amp fuse which is the one that is clicking and causing the Wait to Start and Check engine light to flicker...so I will check those fuses too.
I find the Factory Electrical Manual difficult to understand...but I have one and will be going over it like a madman ...electrical is not my area of expertise.... But I will give it a shot...I think it is some kind of bad ground..Could it be a bad Ignition switch ? Any Ideas or Input would be appreciated...Sorry for long post ... think I have to tow it to some Auto electric expert...thanks in advance...

 

Do you still have your fuel heater plugged in? If so, try unplugging it. Madpogue replied in another thread that some have reported the fuel heater shorting out, with out blowing fuse 22, which also powers the PCM. Might be worth a shot.

 

I was thinking the same thing but the fuse is OK ..I will still unplug it tomorrow ...just for kicks...thanks for reply ...I will also check the IPR harness for rub -out even though it is newish...

 

I would pull your whole fuel bowl harness> I had two spots where the insulation had broken down and fallen off the IPR wires inside of the loom. It is a 6 pin connector next to the driver's side head, all the sensor connectors, and it is off. Definitely a good thing to inspect if you are having intermittent issues.

 

Well...I replaced all the UVC harnesses and fixed the wires I seen ....Installed a new GPR....Changed IDM's....same ol chit...it still freaks out.....I think it it is in the steering column / assembly.....but I don't know...Basic Nightmare....thanks for all the help....

 

I had a similar issue and the last thing I remember doing was to swap the PCM relay and the horn relay. I was able to start the truck and drive it home. The problem has not returned. I did unplug the fuel bowl heater the day after that though.

Kevin

 

I have thrown in the towel ....I have some options but I think It's time......I will pull the engine/Trans and scrap the rest...

 

Just saw you had a chip, did you remove it completely out the PacM to verify its not tge culprit

 

It's not a chip..It is a PCM Flash and I sent the PCM out to get repaired / Checked and they told me nothing was wrong with it ....

 

Did you try a known good PCM?

 

Ignition switch? Hate to see you give up on it!