Ignition System: Testing and Inspection
IGNITION SIGNAL
Description
The ignition signal from the ECM is sent to and amplified by the power transistor. The power transistor turns
ON and OFF the ignition coil primary circuit. This ON/OFF operation induces the proper high voltage in the coil secondary circuit.
Component Function Check
1.INSPECTION START
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON (READY).
3. Depress the accelerator pedal to start engine.
Does the engine start?
YES-1 - With CONSULT-III: GO TO 2.
YES-2 - Without CONSULT-III: GO TO 3.
NO - Go to SEE Diagnosis Procedure.
2.IGNITION SIGNAL FUNCTION
With CONSULT-III
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON (READY).
3. Perform "POWER BALANCE" in "ACTIVE TEST" mode with CONSULT-III.
4. Make sure that each circuit produces a momentary engine speed drop.
Is the inspection result normal?
YES - INSPECTION END
NO - Go to SEE Diagnosis Procedure.
3.IGNITION SIGNAL FUNCTION
Without CONSULT-III
1. Activate "INSPECTION MODE 1" ( Inspection Mode 1) to start engine, then let engine idle.
2. Read the voltage signal between ECM harness connector and ground.
NOTE:
The pulse cycle changes depending on rpm at idle.
Is the inspection result normal?
YES - INSPECTION END
NO - Go to SEE Diagnosis Procedure.
Diagnosis Procedure
1.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
2. Check the voltage between ECM harness connector and ground.
Is the inspection result normal?
YES - GO TO 2.
NO - Go to POWER SUPPLY AND GROUND CIRCUIT.
2.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect condenser-2 harness connector.
3. Turn ignition switch ON.
4. Check the voltage between condenser-2 harness connector and ground.
Is the inspection result normal?
YES - GO TO 4.
NO - GO TO 3.
3.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-III
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R harness connector F10.
3. Check the continuity between IPDM E/R harness connector and condenser-2 harness connector.
4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES - Go to POWER SUPPLY AND GROUND CIRCUIT.
NO - Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK CONDENSER-2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check the continuity between condenser-2 harness connector and ground.
3. Also check harness for short to power.
Is the inspection result normal?
YES - GO TO 5.
NO - Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK CONDENSER
SEE Component Inspection (Condenser-2)
Is the inspection result normal?
YES - GO TO 6.
NO - Replace condenser. For the condenser number, [1][2]Electrical Diagrams. For the condenser arrangement, Harness Locations.
6.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-V
1. Reconnect all harness connectors disconnected.
2. Disconnect ignition coil harness connector.
3. Turn ignition switch ON.
4. Check the voltage between ignition coil harness connector and ground.
Is the inspection result normal?
YES - GO TO 7.
NO - Repair open circuit or short to ground or short to power in harness or connectors.
7.CHECK IGNITION COIL GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check the continuity between ignition coil harness connector and ground.
3. Also check harness for short to power.
Is the inspection result normal?
YES - GO TO 8.
NO - Repair open circuit or short to ground or short to power in harness or connectors.
8.CHECK IGNITION COIL OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check the continuity between ECM harness connector and ignition coil harness connector.
3. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES - GO TO 9.
NO - Repair open circuit or short to ground or short to power in harness or connectors.
9.CHECK IGNITION COIL WITH POWER TRANSISTOR
SEE Component Inspection (Ignition Coil with Power Transistor).
Is the inspection result normal?
YES - GO TO 10.
NO - Replace malfunctioning ignition coil with power transistor. Service and Repair.
10. CHECK INTERMITTENT INCIDENT
Intermittent Incident.
- INSPECTION END
Component Inspection (Ignition Coil with Power Transistor)
1.CHECK IGNITION COIL WITH POWER TRANSISTOR-I
1. Turn ignition switch OFF.
2. Disconnect ignition coil harness connector.
3. Check resistance between ignition coil terminals as follows.
Is the inspection result normal?
YES - GO TO 2.
NO - Replace malfunctioning ignition coil with power transistor. Refer to . Service and Repair
2.CHECK IGNITION COIL WITH POWER TRANSISTOR-II
CAUTION:
Do the following procedure in the place where ventilation is good without the combustible.
1. Turn ignition switch OFF.
2. Remove fuel pump fuse in IPDM E/R to release fuel pressure. For the fuse number, [1][2]Electrical Diagrams. For the fuse arrangement, Fuse, Connector And Terminal Arrangement.
NOTE:
Do not use CONSULT-III to release fuel pressure, or fuel pressure applies again during the following procedure.
3. Turn ignition switch ON (READY).
4. Depress accelerator pedal and keep it.
5. After engine stalls, check DTC.
If DTC is detected, erase DTC and go to next steps.
If DTC is not detected, go to next steps.
6. Turn ignition switch OFF.
7. Remove all ignition coil harness connectors to avoid the electrical discharge from the ignition coils.
8. Remove ignition coil and spark plug of the cylinder to be checked. Service and Repair.
9. Repeat steps 3 to 5 for two or three times to remove combustion gas in the cylinder.
10. Connect spark plug and harness connector to ignition coil.
11. Fix ignition coil using a rope etc. with gap of 13 - 17 mm (0.52 - 0.66 in) between the edge of the spark plug and grounded metal portion as shown in the figure.
12. Turn ignition switch ON (READY).
13. Depress accelerator pedal for about 3 seconds, and check whether spark is generated between the spark plug and the grounded metal portion.
CAUTION:
- Do not approach to the spark plug and the ignition coil within 50 cm (19.7 in). Be careful not to get an electrical shock while checking, because the electrical discharge voltage becomes 20kV or more.
- It might cause to damage the ignition coil if the gap of more than 17 mm (0.66 in) is taken.
NOTE:
When the gap is less than 13 mm (0.52 in), the spark might be generated even if the coil is malfunctioning.
Is the inspection result normal?
YES - INSPECTION END
NO - Replace malfunctioning ignition coil with power transistor. Service and Repair.
Component Inspection (Condenser-2)
1.CHECK CONDENSER-2
1. Turn ignition switch OFF.
2. Disconnect condenser-2 harness connector. For the condenser number, [1][2]Electrical Diagrams. For the condenser arrangement, Harness Locations.
3. Check resistance between condenser-2 terminals as follows.
Is the inspection result normal?
YES - INSPECTION END
NO - Replace condenser-2. For the condenser number, [1][2]Electrical Diagrams. For the condenser arrangement, Harness Locations.