OBD-II vehicles typically have oxygen sensors in the exhaust flow ahead of and behind the catalytic converter(s), twice the number of sensors as non-OBD-II vehicles. OBD-II systems are also capable of monitoring misfires based on individual engine cylinder. Some codes point to the oxygen sensor as a possible problem, but to be sure, it’s often best to make voltage measurements on the sensors to determine its health.OBD-II vehicles typically have oxygen sensors in the exhaust flow ahead of and behind the A modern vehicle with On-Board Diagnostics (OBD) holds substantial microprocessor power and has small control modules that communicate with each other throughout the vehicle. They can monitor vehicle health, and through the use of sensors, engine control is now a highly sophisticated process. Whenever you have drivability problems or your vehicle flags a fault code, you’ll often need to do some troubleshooting to get to the root of the problem. A specific code may or may not point you to a specific component that is out of spec. It may suggest several possible components that could be at fault. In this case, further troubleshooting may be necessary. It may be a situation where you can monitor the sensor voltage level, such as on an operating oxygen sensor, or you may have to take other voltage or resistance measurements at a sensor to further determine its condition. Factory repair manuals often specify the measurements that need to be made. Electronics and moisture just do not mix well. Should you happen to dunk your rig and put an electronic control module under water, it’s best to remove the battery power, delid the module if possible, and let it dry completely before reapplying power to it. If this is not an option, we’ve seen times when a liberal dose of a water displacement product (such as WD-40) has cleared the moisture sufficiently to allow use of the module.Electronics and moisture just do not mix well. Should you happen to dunk your rig and put This Throttle Position Sensor (TPS) was found to be faulty at 150,000 miles. As this was on an older non-diagnostic system, there was no specific code flagged. The sensor voltage was checked while on the vehicle, and resistance readings of the sweeping resistor taken after removal. Results showed the readings were erratic and out of spec. Once disassembled (shown here) it was clear that the metallic traces inside were worn and degraded.This Throttle Position Sensor (TPS) was found to be faulty at 150,000 miles. As this was o When a sensor code is flagged, it’s possible that the problem is due to a poor harness connection. In an auto environment, some of the most common points of electrical system failure can be traced to a degraded electrical connection. Sometimes unplugging and replugging a sensor connector can improve a connection that may have vibrated loose or become slightly corroded. Ground wires running to sensors may also become resistive, so should be checked for good connection and solid voltage grounding.When a sensor code is flagged, it’s possible that the problem is due to a poor harness con By Jay Kopycinski Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!