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 VACUUM DIAGRAMS article to verify routing and connections (if necessary). Inspect air induction system for possible vacuum leaks.
MECHANICAL INSPECTION
| WARNING | DO NOT use ignition switch during compression tests on fuel injected vehicles. Use a remote starter to crank engine. Fuel injectors on many models are triggered by ignition switch during cranking mode, which can create a fire hazard or contaminate the engine's oiling system. |
SPARK TEST (ES300, GS300 & SC300)
Note. On ES300, three ignition coils are used and are located on left valve cover.
| CAUTION | To prevent fuel from being injected during cranking in the following procedure, crank engine for no more than 5-10 seconds at a time. |
- Disconnect ignition coil connector. Disconnect injector connector for cylinder being tested. Remove ignition coil to be checked. Remove spark plug. Connect spark plug to coil and reconnect ignition coil connector. Ground the spark plug.
- Check plug for spark while cranking engine. If spark is not present, turn ignition off. Check ignition coil and ignitor connectors. Repair as necessary. If connections are good, using an ohmmeter, check resistance of secondary ignition wires. Resistance should be less than 25000 ohms.
- If resistance is not as specified, replace wires as necessary. If wires are good, turn ignition on. Using a voltmeter, check for battery voltage between ground and positive terminal (Black/Red wire on ES300 or Black/White wire on GS300 and SC300) at ignition coil and ignitor connectors.
- If battery voltage is not present, repair circuit between ignition switch and ignition coil or ignitor. If battery voltage is present, check resistance between terminals of ignition coil connector (ignition coil primary resistance). If resistance is not as specified, replace ignition coil. See «IGNITION COIL RESISTANCE TABLE (ES300)»(ref-22506-S12288409972001010300000) or «IGNITION COIL RESISTANCE TABLE (GS300 & SC300)»(ref-22506-S40283227062001010300000) .
- If resistance is as specified, check resistance between terminals of Camshaft Position (CMP) sensor. See «SENSOR RESISTANCE»(ref-22506-S22260831712001010300000) table. If resistance is not as specified, replace CMP sensor. If resistance is as specified, check resistance between terminals of Crankshaft Position (CKP) sensor. See «SENSOR RESISTANCE»(ref-22506-S22260831712001010300000) table.
- If resistance is not as specified, replace CKP sensor. If resistance is as specified, check for ignitor circuit malfunction (IGT signal). If IGT signal from ECM is defective a Diagnostic Trouble Code (DTC) should set in ECM memory. See testing procedure for DTC P1300 in TESTS W/CODES article. If IGT signal circuit is okay, substitute another ignitor and recheck system operation.
SPARK TEST (GS400, LS400 & SC400)
| CAUTION | To prevent fuel from being injected during cranking in the following procedure, crank engine for no more than 5-10 seconds at a time. |
- Disconnect ignition coil connector. Disconnect injector connector for cylinder being tested. Remove ignition coil to be checked. Remove spark plug. Connect spark plug to coil and reconnect ignition coil connector. Ground the spark plug.
- Check plug for spark while cranking engine. If spark is not present, turn ignition off. Check ignition coil and ignitor connectors. Repair as necessary. If connections are good, substitute another ignition coil with ignitor and recheck system operation.
- If problem persists, turn ignition on. Using a voltmeter, check for battery voltage between ground and positive terminal (Black/White wire on GS400 and SC400 or Black/Red wire on LS400) at ignition coil connector.
- If battery voltage is not present, repair circuit between ignition switch and ignition coil or ignitor. If battery voltage is present, check resistance between terminals of Camshaft Position (CMP) sensor. See «SENSOR RESISTANCE»(ref-22506-S22260831712001010300000) table. If resistance is not as specified, replace CMP sensor. If resistance is as specified, check resistance between terminals of Crankshaft Position (CKP) sensor. See «SENSOR RESISTANCE»(ref-22506-S22260831712001010300000) table.
- If resistance is not as specified, replace CKP sensor. If resistance is as specified, check for ignitor circuit malfunction (IGT signal). If IGT signal from ECM is defective a Diagnostic Trouble Code (DTC) should set in ECM memory. See testing procedure for DTC P1300 in TESTS W/CODES article. If IGT signal circuit is okay, substitute another ignition coil with ignitor and recheck system operation.
| Application | Primary | Secondary |
|---|
| Aisan (3) |
| Cold (1) | .70-.94 | 10,800-14,900 |
| Hot (2) | .85-1.10 | 13,100-17,500 |
| Diamond (3) |
| Cold (1) | .70-.94 | 6,800-11,700 |
| Hot (2) | .85-1.10 | 8,600-13,700 |
| (1) Coil temperature of 14-122°F (-10-50°C). (2) Coil temperature of 123-212°F (51-100°C). (3) Name of ignition coil manufacturer. |
| (1) | Coil temperature of 14-122°F (-10-50°C). |
| (2) | Coil temperature of 123-212°F (51-100°C). |
| (3) | Name of ignition coil manufacturer. |
| Application | Primary | Secondary |
|---|
| Cold (1) | .33-.52 | 8,500-14,700 |
| Hot (2) | .42-.61 | 10,800-17,200 |
| (1) Coil temperature of 14-122°F (-10-50°C). (2) Coil temperature of 123-212°F (51-100°C). |
| (1) | Coil temperature of 14-122°F (-10-50°C). |
| (2) | Coil temperature of 123-212°F (51-100°C). |
| Application | Ohms |
|---|
| Camshaft Sensor |
| Cold (1) | 835-1400 |
| Hot (2) | 1060-1645 |
| Crankshaft Sensor |
| Cold (1) | 1630-2740 |
| Hot (2) | 2065-3225 |
| (1) Sensor temperature of 14-122°F (-10-50°C). (2) Sensor temperature of 123-212°F (51-100°C). |
| (1) | Sensor temperature of 14-122°F (-10-50°C). |
| (2) | Sensor temperature of 123-212°F (51-100°C). |
