September 2014 Archives - UnderhoodService
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
A/C Oil Service: Avoid Compressor Failure With Proper Maintenance

HVAC systems often fail because the air conditioning compressor fails. Not following the proper service procedures or compressor oil recommendations could be factors that contribute to premature compressor failure. Refrigerant Since the mid-‘90s, all vehicles have been using R-134a refrigerant, but soon, vehicles will arrive at your shop equipped with R-1234yf refrigerant. This is the

AC Oil Compressor failure
How Engine Coolant Temperature Sensors Influence The Modern Powertrain

  Considering that roughly 1,500 or more ­different vehicle models are introduced into our domestic market each year, it’s becoming more difficult to predict how a powertrain control module (PCM) will utilize data from a particular sensor or detect an out-of-range sensor in any single vehicle platform. The engine coolant temperature (ECT) ­sensor provides a

ECT sensor data diagnostics