After a long and hot summer and a soft case of blocked writers, I will change the pitch a bit in my last post. It's pretty long, a bit technical, but it's about a day in the life of a automotive technician, a business owner, the technologies we are dealing with and the special problems that we face more often.
I recently consulted a 1999 Suzuki Grand Vitara with the concern of customers of not being able to pass the state inspection of Delaware. The reason for the failure of the inspection was that 3 of the OBDII computer monitors were not configured. Monitors that had not been established in a passing state were; oxygen sensors, catalytic converter and evaporative system. Delaware Motor Vehicle has provided the owner with a hard copy of the "driver's cycle" requirements to allow the monitors to be executed for this specific vehicle. The owner of the vehicle tried 3 times more during 2 months while driving a total of 1043 miles in an effort to establish these monitors. Each repetition produced the same results of failure.
To help you understand the technology and associated terminology that contains the previous paragraph and the following story, I will first explain these terms in more detail;
• Generation of OBDII-On Board diagnostics 2. All vehicles manufactured since 1996 have been designed with this technology in the computer system to meet emission standards approved by the Federation.
• Monitors-Autocontrols carried out by the control module of the power train (computer) in the different systems that emit emissions of the vehicle, as well as control the operation and the performance of the vehicle. When a monitor "sets", it has passed the test.
• Drive cycle: conditions that must be met for the different self-checks (monitor) to configure. Some examples would be the engine temperature, vehicle speed, engine load, outdoor temperature, fuel tank level and internal tank pressure.
I connected one of our diagnostic scanners (a computer that cost $ 6000 to buy and $ 2000 per year to stay up to date) and made a quick analysis of the computer system to find codes. I also checked the monitors that were not configured according to the records of DMV errors. There were no defects stored in the current or pending state and the 3 monitors mentioned above were not executed. A review of the technical boards of current published manufacturers, combined with the automotive forum publication we belong to, did not offer a quick solution to this problem.
With the diagnostic scanner still connected, I have selected all 4 oxygen sensors to control its activity. With the vehicle running, one of the sensors worked at a fixed voltage instead of violating them as needed, but the reading was not out of the parameters to establish a fault code for an obvious deficient sensor. To isolate the cause of this failure, I have tried the sensor again to test the voltage, and then test the voltage directly to the connector of the computer harness and finally jump the circuit To the wiring with a bridge cable to verify and compare the different readings through the circuit. Before these tests, the possible cause was a defective oxygen sensor, a defective wiring for this sensor circuit or an internal fault in the computer. Ultimately, I replaced the failed oxygen sensor.
After trying the system again with the recently installed oxygen sensor, it was time to make a scroll cycle to see if any of the monitors would be running. During the first 10-minute cycle, the sensor of the oxygen sensor set, leaving the catalytic converter and evaporative system monitors still unconfigured. The Delaware motor vehicle allows a 1999 vehicle to pass with 2 unplugged monitors, but I knew better than calling the customer and saying it was repaired and was ready for inspection. I allowed the vehicle to cool for several hours and in the second cycle of 10 minutes; the light of the verification engine was illuminated indicating a fault with one of the statistical converters.
Each monitor has its own criteria and set of prerequisites that should exist before it is executed. There is also a hierarchy about how each monitor is running. In this case, the monitor of the catalyst converter will not run because the oxygen sensor monitor was not set and the computer trusts the oxygen sensors to test the oxygen sensor. # Catalyst efficiency to set this monitor. With the oxygen sensors passing the test, a failure in the emission control system could be determined with an inefficient catalytic converter.
Since the catalytic converter had to be sorted from an out-of-state store, all this took several days. With each diagnostic milestone, I called the client and explained with the same detail. I have illustrated what would have required repairing your vehicle here so that it complies with state inspection requirements.
Ironically, although in the process of replacing the catalytic converter I have received a telephone call asking if we perform the FREE Check the Diagnostics of motor light. At first I frowned, but instead of explaining the economy, I told them to call a local franchise store that offered a free verification of computer code, the required diagnosis and Then you will sell all the pieces to repair the problem. My mind went through the $ 120.00 bill that I paid for a local heating and air conditioning company to diagnose our inoperative central air system for the office that took all 30 minutes max. This happened to the recent notification that our medical plan increased 12% this year and the impact it will have on our current monthly premium that already represents a modest mortgage payment. The phone sounds, it's an appointment, which makes me focus on your request. After; I breathe deeply and go back to the repair task.
After completing the replacement of the failed catalytic converter, I have completed another 10-minute cycle and this time all monitors are set, except the evaporative system (one of the most difficult to execute and configure monitors). There are no pending errors that were stored in the computer system, so I had a 99% confidence that the vehicle would now pass the state inspection of Delaware. The next day, the client called to inform that the vehicle finally passed.
Back were the days when we could open the bell and turn a screw or just adjust the time and the car worked better. I'm upset that technology has accelerated to levels far superior to comparable operations, but is it not recognized accordingly? Absolutely! But at the end of the day I am moving home with a strong sense of accomplishment to have a satisfied client that makes it worthwhile.
Source by Dave McCracken