Foreign service

Motor,  Sep 2002  by Marinucci, Dan

• E-mail
• Print
• Link

They say hindsight is always 20/20. When I look back on that hurried scope test, I realize that the different display and unfamiliar settings confused me. Yes, I saw the primary ignition current switching high and low. But I missed two critical details that would have nailed the diagnosis right then and there.

My buddy phoned me later that day to say that two additional tests conducted after I left nailed the diagnosis. First, they remembered that on a Chrysler diagnostic system, you could use a scan tool to operate the coil. When the tech commanded the ECM to fire the coil, nothing happened. Second, because a coworker drives the same vehicle, they just swapped his ECM into the problem minivan and it started up! Then they installed a remanufactured ECM and the job was done.

Although my friend had to return the old ECM as a core, he kindly kept it for an extra day so I could swap it into the other vehicle and scope-test it. I don't pretend to know everything about ignition analysis; on the contrary, I'm learning all the time. But my gut told me this should have been a slam-dunk, several-minute diagnosis without a scanner, test light, headlamp and jumper wires. Tune in next month to see what I discovered.

Copyright Hearst Business Publishing Sep 2002
Provided by ProQuest Information and Learning Company. All rights Reserved