ENORMIS Mobile Specialties Diagnoses ECM Problem for Client’s F-150

Chester’s 1999 Ford F-150 had a no-start issue. The 1999 Ford F-150 shut down while Chester was driving down the road and would no longer start. In an effort to get his truck working again, he had someone start replacing parts. He tried replacing a fuel pump. .. Nope. He tried replacing the fuse box … Nope. The F-150 still would not start.

Chester decided he had wasted enough time and money hon guessing with new parts and had the vehicle towed to ENORMIS Mobile Specialties for a true diagnosis. When the F-150 arrived at ENORMIS, our MECP-certified technician Chris Brown verified the issue and  set out to determine  the cause of the no-start. He did some initial diagnostic testing — battery voltage, starter engagement — and  scanned for trouble codes, but the scanning tool could not communicate with the F-150’s engine control module (ECM). The module was offline and not allowing the vehicle to start. Chris determined that the ECM operates off a constant 5 volt reference to the ECM. This F-150’s 5 volt reference was fluctuating to as high as 5.8 volts and as low as 0 volts.

We pushed the Ford F-150 into the garage and inspected it thoroughly to check over all the wiring. Guess what? Chris found wires pinched against some metal. This pinch point had severed four wires and pinched numerous other wires. The pinch led to power backfeeding into the ECM and shorted it out.

We removed the severed and pinched wires, and then we soldered in and lengthened new wires, which re-routed the harness  away from the pinch point. Once the 5 volt reference was restored to the ECM, we installed and programmed a new ECM, allowing the truck to start — and start reliably.

Sounds like a lot of work for a 1999 F-150, right? Well, as Chester says, “It ain’t pretty, but it’s paid for.”

If you need a shop to actually solve your no-start problem (instead of guessing), you need the best. We are experts at electrical system problem-solving. Fill out the contact form here for information about our problem-solving services.