Electronic Spark Advance (ESA) Control System

SYSTEM INSPECTION
1. Turn off following electrical loads.
- Power steering
- A/C
2. Connect a timing light to the high-tension lead of No.1 cylinder.




3. Connect the data link connector terminals TEN and GND with a jumper wire.




4. Start the engine and verify that the ignition timing retards as the engine warms up.
5. If not as specified, check the ECM terminal 3G (Engine coolant temperature sensor) voltage.
6. Disconnect a jumper wire.
7. Verify that the engine is completely warmed up.
8. Increase the engine speed and verify that the ignition advances accordingly.
9. If not as specified, check voltage at following terminals.
- ECM terminal 3B (Mass air flow sensor)
- ECM terminal 4E 4H (Crankshaft position sensor)




Scope Pattern