Q: What are the primary checks for the ignition coil/igniter units used on Toyota Avalon and Toyota Solara?
A: Primary and secondary resistance checks for ignition coil/Igniter units on some Toyota and Lexus models don't apply to newer ones. The only test is to substitute a known good unit, which isn't practical for home mechanics. If all other ignition malfunction causes are ruled out, a faulty ignition coil/igniter unit is likely. To check primary resistance on some models, disconnect the electrical harness connector(s) from each coil and use an ohmmeter across the coil primary terminals. For secondary resistance, detach and label the spark plug wires from each coil and use an ohmmeter across the two secondary terminals. If resistance readings are off, replace the coil. When replacing, disconnect the battery's negative cable and follow specific removal and installation procedures for four-cylinder or V6 models.