engine control module Archives - UnderhoodService
VIDEO: Understanding Bias Voltage

Andrew Markel goes over bias voltage and how this startup process allows a handshake between modules and sensors. Sponsored by Standard.

VIDEO: Stop-Start System Service Opportunities

Andrew Markel discusses service opportunities for vehicle stop-start systems and how several modules are involved in the activation of the feature. Sponsored by Bosch Automotive Service Solutions.

State-Of-Charge And Charging Systems Diagnostics On Late-Model GM Vehicles

On 2007 and up GM vehicles, using conventional battery and charging systems tests can prove inconclusive. This is because of GM’s Electrical Power Management (EPM) system designed to monitor and control the charging systems and send diagnostic messages to alert the driver of possible problems. The EPM system primarily utilizes existing on-board computer capabilities to maximize the effectiveness of the charging systems, manage the load, improve battery state-of-charge and life, and minimize the system’s impact on fuel economy.

Driveability Diagnostics and Direct Injection

Direct injection is becoming standard on more and more late-model vehicles. These systems can be a diagnostic challenge, but with the right foundation, problems can be solved profitably. Years ago, all a low-level technician needed to diagnose a fuel problem was a set of “noid lights,” a fuel pressure gauge and maybe a meter. These

Direct Injection Fuel System