Engine Controls - Basic Testing: Diagnosis Toyota Avalon XX10

VISUAL INSPECTION

Visually inspect all electrical wiring, looking for chafed, stretched, cut or pinched wiring. Ensure electrical connectors fit tightly and are not corroded. Ensure vacuum hoses are properly routed and are not pinched or cut. See the VACUUM DIAGRAMS article to verify routing and connections (if necessary). Inspect air induction system for possible vacuum leaks.

SPARK TEST

1. Disconnect negative battery cable. Remove cover located above ignition coils.
2. Disconnect electrical connectors from ignition coils. Remove bolts and ignition coil assemblies. Reconnect negative battery cable and electrical connectors on ignition coils.
3. Remove spark plugs. Install spark plug on each ignition coil. Ground spark plug against cylinder block. CAUTION: To prevent gasoline from being injected, DO NOT crank engine for longer than 2 seconds.
4. Crank engine and check for spark. If spark does not occur, check ignition coil and ignitor electrical connections.
5. If electrical connections are okay, turn ignition on. Ensure voltage exists at ignition coil positive terminal. If voltage exists, proceed to step 6). If voltage does not exist, check wiring between ignition switch, ignition coil and ignitor. See wiring diagram in the WIRING DIAGRAMS article.
6. Check ign. coil resistance. See «IGNITION COIL RESISTANCE»(ref-21707-S09965346472001010300000) . Replace ignition coil if resistance is not within specification. If ignition coil resistance is within specification, proceed to step 7).
7. Check resistance of camshaft position sensor(s) and crankshaft position sensor. See «CAMSHAFT POSITION SENSOR»(ref-21707-S27971999722001010300000) and «CRANKSHAFT POSITION SENSOR»(ref-21707-S00995749892001010300000) .
8. Replace camshaft position sensor or crankshaft position sensor if resistance is not within specification. If camshaft position sensor and crankshaft position sensor resistance is within specification, proceed to step 9).
9. Check ignition IGT signal from Engine Control Module (ECM). If ignition IGT signal from ECM is defective a diagnostic trouble code will be set in the ECM memory to indicate a ignitor circuit malfunction. See the TESTS W/CODES article for diagnostic trouble code. If IGT signal is okay, substitute another ignitor and recheck system operation. Reinstall ignition coils, spark plugs and remaining components.