When confronted with a fuel control problem on a modern vehicle, contributing writer Gary Goms normally uses short- and long-term fuel trims to determine if the problem is caused by one of many failures such as a vacuum leak or a leaking fuel pressure regulator.
“If you’re like me, you’ll occasionally access the air/fuel ratio (AFR) sensor serial datastream to determine if the sensors are functioning as intended,” Goms says. “But, modern aftermarket scan tools often display AFR sensor data in a conventional 0 to 1.0-volt format, lambda, equivalency ratio, AFR voltage, and even milliamperes, all of which can be confusing, even for veteran diagnostic technicians.”
In the field, the lack of familiarity with a particular datastream can also lead to some serious diagnostic errors. Goms starts off by sorting out this datastream maze by looking at the basics of zirconium dioxide and AFR oxygen sensors.
Go to http://www.import-car.com/fuel-control-diagnostics-datastream/ for the complete article.