PCM Troubles?
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PCM Troubles?
1997 7.3 powerstroke with no modifications other than 6637 filter, downpipe, and straight-pipe exhaust. I was pulling out of my driveway and the truck died and would not start back up. Cranks no problem. Wait to start and check engine light flashing rapidly and IDM relay clicking. I checked fuses and all good. I opened the fuel bowl and found the heater shorted out. Replaced heater along with fuses....same WTS and CEL flashing. I also load tested batteries and both good. I've also kept it on the charger overnight to ensure adequate power.
I've come to the conclusion that the fuel bowl heater shorting sent too much amperage to the PCM because the fuse did not blow as it should have. I tore apart the wiring harness and I have good powers and grounds. Anything else I should look at? Anyone else experienced the fuse not blowing when the heater shorts?
I've come to the conclusion that the fuel bowl heater shorting sent too much amperage to the PCM because the fuse did not blow as it should have. I tore apart the wiring harness and I have good powers and grounds. Anything else I should look at? Anyone else experienced the fuse not blowing when the heater shorts?
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Cross-Country
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Forgot to mention I tried that as well using all 4 of the relays in the box....no change. Contacts in the fuse box look ok. Thanks for the suggestion.
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Follow-up and closure: I sent the PCM and SuperChips chip down to Diesel Technology of Chattanooga (who I highly recommend). The chip was causing the problems detailed above. My guess is that it got fried when the fuel bowl heater shorted. The chip was installed by the previous owner and I have no details on it other than it being branded "SuperChips."
I got the rebuilt PCM back from Diesel Tech and installed it. I have no way of confirming this but the truck seems to be running quieter and smoother. Shifting seems better/smoother too. I'll be curious to see if my fuel economy changes. I was averaging around 14-15 MPG with the chip.
I got the rebuilt PCM back from Diesel Tech and installed it. I have no way of confirming this but the truck seems to be running quieter and smoother. Shifting seems better/smoother too. I'll be curious to see if my fuel economy changes. I was averaging around 14-15 MPG with the chip.
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joletson
1999 - 2003 7.3L Power Stroke Diesel
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Dec 19, 2008 07:02 PM
