You searched for PCM - Page 71 of 71 - UnderhoodService
Secondary Ignition System Maintenance

As one might expect, the introduction of low-maintenance ignition systems has changed how we sell and service secondary ignition system parts for import vehicles. Most import nameplates have, for example, replaced conventional distributor ignition systems with distributorless or coil-on-plug (COP) ignitions in order to reduce the number of wearing parts in the secondary or high-voltage

Flash Reprogramming

Would you believe flash reprogrammable PCMs have been in vehicles for more than a decade? The first such application was the 1990 Geo Storm. Why a humdrum car like the Storm would be the first to receive a flash reprogrammable computer system is unknown. You’d think GM would have chosen a more high profile vehicle

Analyzing Ignition Misfires and Plotting a Diagnostic Course

Uh oh. The Malfunction Indicator Lamp (MIL) is on, and you’ve just found a misfire code. It’s a code P0304, which tells you cylinder number four is misfiring. There are no other codes and the engine has a steady miss. Now what? Misfire diagnosis in this kind of situation should be fairly easy. You have