M20F-FXS, M20G-FXS ENGINE CONTROL SFI SYSTEM Ignition Circuit
DESCRIPTION
A direct ignition system is used on this vehicle. The direct ignition system is a 1 cylinder ignition system which ignites one cylinder with one ignition coil. In the 1 cylinder ignition system, one spark plug is connected to the end of the secondary winding. High voltage is generated in the secondary winding and is applied directly to the spark plug. The spark of the spark plug passes from the center electrode to the ground electrode.
The ECM determines the ignition timing and transmits the ignition signals for each cylinder. Using the ignition signal, the ECM turns on and off the power transistor inside the igniter, which switches on and off a current to the primary coil. When the current to the primary coil is cut off, high voltage is generated in the secondary coil and this voltage is applied to the spark plugs to create sparks inside the cylinders.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
- NOTICE:
-
Inspect the fuses for circuits related to this system before performing the following procedure.
- HINT:
-
Perform a spark test first. If none of the cylinders spark, or if only some cylinders do not spark, check this circuit to determine if the ignition coil and spark plug are normal.
PROCEDURE
| *a | Front view of wire harness connector
(to Ignition Coil Assembly) |
Disconnect the ignition coil assembly connectors.
Turn the ignition switch to ON.
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
Tester Connection Condition Specified Condition C1-1 (+B) - C1-3 (GND) Ignition switch ON 11 to 14 V C3-1 (+B) - C3-3 (GND) Ignition switch ON 11 to 14 V C5-1 (+B) - C5-3 (GND) Ignition switch ON 11 to 14 V C7-1 (+B) - C7-3 (GND) Ignition switch ON 11 to 14 V
- Result:
Proceed to OK NG
OK
NG
Disconnect the ignition coil assembly connectors.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition C1-2 (IGT1) - C141-49 (IGT1) Always Below 1 Ω C3-2 (IGT2) - C141-48 (IGT2) Always Below 1 Ω C5-2 (IGT3) - C141-47 (IGT3) Always Below 1 Ω C7-2 (IGT4) - C141-46 (IGT4) Always Below 1 Ω C1-2 (IGT1) or C141-49 (IGT1) - Body ground and other terminals Always 10 kΩ or higher C3-2 (IGT2) or C141-48 (IGT2) - Body ground and other terminals Always 10 kΩ or higher C5-2 (IGT3) or C141-47 (IGT3) - Body ground and other terminals Always 10 kΩ or higher C7-2 (IGT4) or C141-46 (IGT4) - Body ground and other terminals Always 10 kΩ or higher
- Result:
Proceed to OK NG
OK
NG
Disconnect the ignition coil assembly connectors.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition C1-3 (GND) - Body ground Always Below 1 Ω C3-3 (GND) - Body ground Always Below 1 Ω C5-3 (GND) - Body ground Always Below 1 Ω C7-3 (GND) - Body ground Always Below 1 Ω
- Result:
Proceed to OK NG
OK
NG
Disconnect the IGP-MAIN relay from No. 1 engine room relay block.
Disconnect the ignition coil assembly connectors.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition 3 (IGP-MAIN relay) - C1-1 (+B) Always Below 1 Ω 3 (IGP-MAIN relay) - C3-1 (+B) Always Below 1 Ω 3 (IGP-MAIN relay) - C5-1 (+B) Always Below 1 Ω 3 (IGP-MAIN relay) - C7-1 (+B) Always Below 1 Ω 3 (IGP-MAIN relay) or C1-1 (+B) - Body ground and other terminals Always 10 kΩ or higher 3 (IGP-MAIN relay) or C3-1 (+B) - Body ground and other terminals Always 10 kΩ or higher 3 (IGP-MAIN relay) or C5-1 (+B) - Body ground and other terminals Always 10 kΩ or higher 3 (IGP-MAIN relay) or C7-1 (+B) - Body ground and other terminals Always 10 kΩ or higher
- Result:
Proceed to OK NG
OK
NG