Advanced Automotive Fault Diagnosis
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LÔØI NOÙI ÑAÀU, ledklok
| 3.3.3 OBD scanner (AutoTap)
Author’s Note: This section will outline the use and fea- tures of the AutoTap scanner. I have chosen this par- ticular tool as a case study because it provides some very advanced features at a very competitive price. At the time of writing (2006) the price was about £140/$200 – very reasonable for such a powerful tool. The scanner is designed to work with OBD2 systems. However, it worked fine on all the EOBD sys- tems I have used it on so far. For more information: www.autotap.com. Like any other scan tool or code reader, the AutoTap scan tool connects the special OBD2 (CAN) plug-in-port on or under the dash (Figure 3.10). A USB connection then makes the scanner connection to a computer. The AutoTap scanner translates the signals from the vehicle’s computer- controlled sensors to easy-to-read visual displays. It also reads out the diagnostic trouble codes (DTCs) (Figure 3.11). The software allows the technician to choose which parameters or signals they want to see and whether you want to view them in tables or as graphs, meters or gauges (Figure 3.11). It is possible to set the ranges and alarms and pick display colours. Once a screen config- uration is created it can be saved for future use. Different screen configurations are useful for different vehicles, or perhaps one for major maintenance, one for tuning, one for quick checks at the track. Lots of data is provided in easy-to-read views with multiple parameters. Graphs can be used to show short-term logs, and gauges for instant readings. Tools and equipment 31 Figure 3.8 Snap-on scanner Figure 3.9 AutoTap scanner and extension cable Figure 3.10 Diagnostic connector DTCs can be checked immediately on con- necting the scanner and starting up the software. This gives the critical info needed in the shortest time possible. When repairs are completed the tool can be used to turn off the malfunction indi- cator light (MIL). This light is also described as the check engine light. The software will also log data, for example, during a road test. This is particularly useful for diagnosing intermittent faults. The data can be played back after a road or dynamometer test. It can also be exported to a spreadsheet file for later analysis. Overall, to read live data and get access to powertrain (engine related) system DTCs, this is an excellent piece of equipment. tải về 7.07 Mb. Chia sẻ với bạn bè của bạn:
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