2000 E-350 No-start/No-communication

mchan68 · September 28, 2007

Well guys, here's a good job for a late Friday afternoon. Came in on the hook, the customer complained of intermittent stalling, would not restart. Came in about two weeks ago. I did my KOEO/KOER tests monitor PIDs, EVERYTHING was well within specs. No CMDTCs even. He just had it to another shop that replaced the starter and batteries. Now, can't seem to boot up to IDS. VCM is getting power when connected to DLC. Got power to IDM and PCM relays when key on. I tried unplugging ICP, EBP, CMP so far, NO GO. I even tried unplugging the 42-pin engine connector, still NO GO. I was thinking v-ref short to ground. The guy did mention his interior and exterior lights flickering on and off a few times intermittently. I know it's going to be elctrical. Just wondering if anyone has come across any symptom similar to this? I am going to be towing this into the shop Monday with the forklift, in order to be able to dig further. I'm thinking my next step is to unplug the fuel heater. Any ideas? Unit has 230,000 kms.

Jeff Clyde · September 29, 2007

just finished doing one on the side of hwy 401 for the same reason. died while driving and no communication; pcm fuse blown. have done a couple this week for the heater element being the culprit. good luck

Keith Browning · September 29, 2007

Ahhh. The good ol heater rot job! Don't get to see many of those any more. When the PCM fuse is blown that is the first thing I look for.

mchan68 · October 2, 2007

Well, further "digging" revealed, sure enough, a shorted WIF sensor/heater that melted the wires, exposing metal strands. Upon removal of the water separator housing, I found the water separator drain had been plugged with a bolt, and two worm clamps installed. Replaced water separator housing assembly and main engine harness. STILL unable to communicate with PCM/start vehicle!!!! Checked PCM/IDM relays= GOOD, checked the V-ref circuits= GOOD, checked PCM diode and compared reading with one from a new unit= GOOD, fuel pump not getting power (my guess is it's not being commanded. Checked for power to manifold air heater and glow relays when key on= GOOD. Checked ALL BJB and CJB fuses= GOOD!!! Running out of ideas!!!

mchan68 · October 3, 2007

A little more info to add, when turning the key on, the "service engine soon" light does illuminate, so I guess that means there is power going to the PCM, but I don't hear any clicking, nor does the "wait to start" light illuminate, yet I still get power to both the glow and manifold heater relays. Something is obviously missing here. Is there any possibility of other damage that only a shorted WIF sensor/fuel heater could have caused?

Bruce Amacker · October 3, 2007

I'd say it's time for a breakout box and a scope (or DVOM). Do you have a "known good" PCM to try in? I've got one from a 99 F-model, but you ain't exactly close.....

Shorting the fuel heater should not cause any PCM damage.

Good Luck!

mchan68 · October 3, 2007

Checked data bus + & data bus - as well as self-test circuit from DLC to the PCM (pins 13, 15 & 16), all good. Replaced PCM, truck fired up right away!!! Still have a hard time believing a shorted WIF sensor/fuel heater circuit could burn out a PCM.