< 2.0L ENGINE >
This system is provided with two ignition coils (A and B) with built-in ignition power transistors for the number 1 and number 4 cylinders, and number 2 and number 3 cylinders respectively.
Interruption of the current flowing in the primary side of ignition coil A generates a high voltage in the secondary side of ignition coil A.
The high voltage generated is applied to the spark plugs of number 1 and number 4 cylinders to generate sparks. At the time that the sparks are generated at both spark plugs, if one cylinder is at the compression stroke, the other cylinder is at the exhaust stroke, so that ignition of the compressed air/fuel mixture occurs only for the cylinder which is on the compression stroke.
In the same way, when the primary current flowing in ignition coil B is interrupted, the high voltage thus generated is applied to the spark plugs of number 2 and number 3 cylinders.
The engine control module (ECM) or powertrain control module (PCM) controls the two ignition power transistors to turn them alternately ON and OFF. This causes the primary currents in the ignition coils to be alternately interrupted and allowed to flow to fire the cylinders in the order 1 - 3 - 4 - 2.
The ECM or PCM determines which ignition coil should be controlled by means of the signals from the camshaft position sensor and from the crankshaft position sensor.
It also detects the crankshaft position in order to provide ignition at the most appropriate timing in response to the engine operation conditions. When the engine is cold or operated at high altitudes, the ignition timing is slightly advanced to provide optimum performance.
Scheme 1
< 2.4L ENGINE >
This system is provided with four ignition coils with built-in ignition power transistors for each of the cylinders.
Interruption of the primary current flowing in the primary side of ignition coil generates a high voltage in the secondary side of ignition coil.
The engine control module (ECM) or powertrain control module (PCM) controls the four ignition power transistors to turn them alternately ON and OFF. This causes the primary currents in the ignition coils to be alternately interrupted and allowed to flow to fire the cylinders in the order 1-3-4-2.
The ECM or PCM determines which ignition coil should be controlled by means of the signals from the camshaft position sensor which is incorporated in the camshaft and from the crankshaft position sensor which is incorporated in the crankshaft.
It also detects the crankshaft position to provide ignition at the most appropriate timing in response to the engine operation conditions.
When the engine is cold or operated at high altitudes, the ignition timing is slightly advanced to provide optimum performance.
Scheme 2
SPECIAL TOOL
SPECIAL TOOL SPECIFICATIONS TOOL TOOL NUMBER AND NAME SUPERSESSION APPLICATION MD998773 Knock sensor wrench MD998773-01 Knock sensor removal and installation
Scheme 3
KNOCK CONTROL SYSTEM CHECK
Check the knock sensor circuit if diagnostic trouble code, No. P0325 is shown.
Refer to DTC P0325: KNOCK SENSOR CIRCUIT .
Refer to DTC P0325: KNOCK SENSOR CIRCUIT .
Check by the following procedure, and replace the coil if there is a malfunction.
SECONDARY COIL RESISTANCE CHECK
Measure the resistance between the high-voltage terminals of the ignition coil.
Standard value: 8.5 - 11.5 kohms
Scheme 4
Scheme 5
Note. An analog-type ohmmeter should be used.
Note. Connect the negative probe of the ohmmeter to terminal 1.
| CAUTION | This test must be performed quickly (in less than 10 seconds) to prevent coil from burning and ignition power transistor from breaking. |
- Connect and disconnect 1.5 V battery between terminals 2 and 3, and observe the ohmmeter whether there is continuity or not.
- If results do not agree with the table below, replace the primary coil and ignition power transistor assembly.
| 1.5 V POWER SUPPLY BETWEEN 2 - 3 | CONTINUITY BETWEEN 1 - 2 |
|---|---|
| Current flowing | Yes |
| Current not flowing | No |
CONTINUITY REFERENCE
Check by the following procedure, and replace the coil if there is a malfunction.
Scheme 6
Note. An analog-type ohmmeter should be used.
Note. Connect the negative probe of the ohmmeter to terminal 1.
| CAUTION | This test must be performed quickly (in less than 10 seconds) to prevent coil from burning and ignition power transistor from breaking. |
- Connect and disconnect 4.5 - 9.0 V battery between terminal No. 2 and No. 3, and observe the ohmmeter whether there is continuity or not.
- If results do not agree with the table below, replace the primary coil and ignition power transistor assembly.
| 4.5 - 9.0 V POWER SUPPLY BETWEEN 2 - 3 | CONTINUITY BETWEEN 1 - 2 |
|---|---|
| Current flowing | Yes |
| Current not flowing | No |
CONTINUITY REFERENCE
SECONDARY COIL CHECK
Note. It is impossible to check the secondary coil through the continuity check as a diode is integrated in the secondary coil circuit of this ignition coil. Accordingly, check the secondary coil in the following procedure.
- Disconnect the ignition coil connector.
- Remove the ignition coil and install a new spark plug to the ignition coil.
- Connect the ignition coil connector.
- Ground the side electrode of the spark plug and crank the engine.
- Check that spark is produced between the electrodes of the spark plug.
- If no spark plug is produced, replace the ignition coil with a new one and recheck.
- If spark is produced with the new ignition coil, replace the old one as it is faulty. If no spark is produced again, the ignition circuit is suspected as faulty. Check the ignition circuit.
Measure the resistance of the all spark plug leads.
- Check the cap and coating for cracks.
- Measure the resistance. Limit: 19 kohms
- If resistance is greater than 19 kohms, replace the cable.
Scheme 7
Scheme 8
Scheme 9
- Remove the spark plug and connect to the ignition coil.
- Ground the spark plug outer electrode (body), and crank the engine. Check that there is an electrical discharge between the electrodes at this time.
- Check that the plug is not burned, that the insulator plug is not damaged, and that the seizure state is good.
- If cleaning is required due to carbon deposits, etc., clean using a plug cleaner or wire brush, etc.
- Check the plug gap using a plug gap gauge, and adjust if not within the standard value. Standard value: 1.0 - 1.1 mm (0.039 - 0.043 inch)
Scheme 10
| CAUTION | Do not attempt to adjust the gap of the iridium plug. Cleaning of the iridium plug may result in damage to the iridium tips. Therefore, if carbon deposits must be removed, use a plug cleaner and complete cleaning within 20 seconds to protect the electrode. Do not use a wire brush. |
Check the plug gap and replace if the limit is exceeded.
Standard value: 0.7 - 0.8 mm (0.028 - 0.031 inch)
Limit: 1.2 mm (0.047 inch)
Scheme 11
Refer to DTC P0340: CAMSHAFT POSITION SENSOR CIRCUIT .
Refer to DTC P0340: CAMSHAFT POSITION SENSOR CIRCUIT .
MEASUREMENT METHOD
- Clamp the spark plug cable (Number 1 or 3) with the secondary pickup. NOTE: Because of the two-cylinder simultaneous ignition system, the waves for two cylinders in each group appear during wave observation. However, wave observation is carried out for the cylinder (Number 1 or 3) with the spark plug cable which has been clamped by the secondary pickup. NOTE: Identification of which cylinder wave pattern is displayed can be difficult, but the wave pattern of the cylinder which is clamped by the secondary pickup will be stable, so this can be used as a reference.
- Clamp the spark plug cable (Number 1 or 3) with the trigger pickup. NOTE: Clamp the same sparkplug cable as the one which has been clamped by the secondary pickup.
STANDARD WAVE PATTERN
| Settings | |
|---|---|
| FUNCTION | SECONDARY |
| Pattern height | High (or low) |
| Pattern selector | Raster |
| Engine speed | Curb idle speed |
STANDARD WAVE PATTERN
Scheme 12
| Settings | |
|---|---|
| Pattern selector | Display |
| Pattern height | High (or low) |
| Engine speed | Curb idle speed |
STANDARD WAVE PATTERN
Scheme 13
Example 1
- Wave characteristics: Spark line is high and short.
- Cause of problem: Spark plug gap is too large.
Scheme 14
Example 2
- Wave characteristics: Spark line is low and long, and is sloping. Also, the second half of the spark line is distorted. This could be a result of misfiring.
- Cause of problem: Spark plug gap is too small.
Scheme 15
Example 3
- Wave characteristics: Spark line is low and long, and is sloping. However, there is almost no spark line distortion.
- Cause of problem: Spark plug gap is fouled.
Scheme 16
Scheme 17
- Wave characteristics: Spark line is high and short. Difficult to distinguish between this and abnormal wave pattern example 1.
- Cause of problem: Spark plug cable is not properly connected. (Causing a dual ignition)
Example 5
- Wave characteristics: No waves in wave damping section
- Cause of problem: Short in ignition coil.
Scheme 18
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Scheme 20
Scheme 21
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Scheme 23
REMOVAL AND INSTALLATION < 2.0L ENGINE >
| CAUTION | When the knock sensor replacement is performed, use scan tool MB991958 to initialize the learning value (Refer to INITIALIZATION PROCEDURE FOR LEARNING VALUE IN MFI ENGINE ). |
Scheme 24
Required Special Tool
MD998773: Knock Sensor Wrench
<< A >> KNOCK SENSOR REMOVAL
Use special tool MD998773 to remove the knock sensor.
Scheme 25
>>A<< KNOCK SENSOR INSTALLATION
Use special tool MD998773 to install the knock sensor.
REMOVAL AND INSTALLATION < 2.4L ENGINE >
| CAUTION | When the knock sensor replacement is performed, use scan tool MB991958 to initialize the learning value (Refer to INITIALIZATION PROCEDURE FOR LEARNING VALUE IN MFI ENGINE ). |
Required Special Tool
MD998773: Knock Sensor Wrench
Use special tool MD998773 to remove the knock sensor.
Use special tool MD998773 to install the knock sensor.