ARKRON-A specialized, hand-held tester speeds diagnosis of modern EGR systems, according to Nick Smith, president of Smithtronics, Fenton, Mich. The firm's universal tester enables service technicians to perform functional tests directly on electronically controlled EGR systems.
Functional or live EGR tests are already required for some emission inspections and will be required in the future, he said.
The Smithtronics tester quickly isolates EGR problems via a process of elimination strategy.
If the EGR solenoid vacuum valve and/or EGR valve respond correctly to direct commands from the tester, Mr. Smith explained, the user knows the fundamental EGR system works. Therefore, the EGR problem must be rooted in the computer system or its wiring.
The vehicle's battery powers the Smithtronics EGR tester. Its harness must be connected to the EGR solenoid valve or EGR valve in place of the vehicle wiring harness. The tech starts the engine and tries to operate the EGR with the tester.
If the engine begins running roughly or stalls out, he knows the EGR valve opened-the basic system is working correctly. Within seconds, the user confirms the problem is not among the basic EGR components, so he has to check the engine control computer system instead.
If the EGR valve pintle moves on command from the tester but the engine doesn't react, the EGR passages are clogged. But if the EGR valve or solenoid valve won't work on command from the tester (and vacuum is present on the combination vacuum/electronic systems), that component has failed.
Mr. Smith said his EGR tester complements, rather than replaces familiar scan tools.
The Smithtronics tester presently works on domestic EGRs, and adapters are under development for foreign systems, he said.