3. Turn ignition switch ON.
4. Set shift lever to D (A/T) or 1st (M/T) position.
5. Check voltage between ECM terminals 37 (TP sensor 1 signal), 38 (TP sensor 2 signal) and ground under

the following conditions.

6. If NG, replace electric throttle control actuator and go to the next step. Refer to

EM-27, "Exploded View"

7. Perform

EC-123, "Throttle Valve Closed Position Learning"

8. Perform

EC-124, "Idle Air Volume Learning"

Terminal

Accelerator pedal

Voltage

37
(Throttle position sensor 1)

Fully released

More than 0.36V

Fully depressed

Less than 4.75V

38
(Throttle position sensor 2)

Fully released

Less than 4.75V

Fully depressed

More than 0.36V

P0300, P0301, P0302, P0303, P0304 MISFIRE

EC-249

< DTC/CIRCUIT DIAGNOSIS >

[QR25DE]

P0300, P0301, P0302, P0303, P0304 MISFIRE

On Board Diagnosis Logic

INFOID:0000000009480908

When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the crank-

shaft position (CKP) sensor (POS) signal to vary, ECM can determine that a misfire is occurring.

The misfire detection logic consists of the following two conditions.
1. One Trip Detection Logic (Three Way Catalyst Damage)

On the first trip that a misfire condition occurs that can damage the three way catalyst (TWC) due to over-

heating, the MIL will blink.

When a misfire condition occurs, the ECM monitors the CKP sensor (POS) signal every 200 engine revo-

lutions for a change.

When the misfire condition decreases to a level that will not damage the TWC, the MIL will turn off.

If another misfire condition occurs that can damage the TWC on a second trip, the MIL will blink.

When the misfire condition decreases to a level that will not damage the TWC, the MIL will remain on.

If another misfire condition occurs that can damage the TWC, the MIL will begin to blink again.

2. Two Trip Detection Logic (Exhaust quality deterioration)

For misfire conditions that will not damage the TWC (but will affect vehicle emissions), the MIL will only

light when the misfire is detected on a second trip. During this condition, the ECM monitors the CKP sen-

sor signal every 1,000 engine revolutions.

A misfire malfunction can be detected in any one cylinder or in multiple cylinders.

DTC Confirmation Procedure

INFOID:0000000009480909

CAUTION:

Always drive vehicle in safe manner according to traffic conditions and obey all traffic laws when driv-

ing.

NOTE:

If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at

least 10 seconds before conducting the next test.

WITH CONSULT

1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Restart engine and let it idle for about 15 minutes.
4. Check 1st trip DTC.
5. If 1st trip DTC is detected, go to

EC-250, "Diagnosis Procedure"

NOTE:

If 1st trip DTC is not detected during above procedure, performing the following procedure is advised.

a. Turn ignition switch OFF and wait at least 10 seconds.

Sensor

Input Signal to ECM

ECM function

Crankshaft position sensor (POS)

Engine speed

On board diagnosis of misfire

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0300
0300

Multiple cylinder misfires detected Multiple cylinder misfire.

• Improper spark plug
• Insufficient compression
• Incorrect fuel pressure
• The fuel injector circuit is open or shorted
• Fuel injector
• Intake air leak
• The ignition signal circuit is open or shorted
• Lack of fuel
• Drive plate or flywheel
• Air fuel ratio (A/F) sensor 1
• Incorrect PCV hose connection

P0301
0301

No.1 cylinder misfire detected

No. 1 cylinder misfires.

P0302
0302

No. 2 cylinder misfire detected

No. 2 cylinder misfires.

P0303
0303

No. 3 cylinder misfire detected

No. 3 cylinder misfires.

P0304
0304

No. 4 cylinder misfire detected

No. 4 cylinder misfires.

EC-250

< DTC/CIRCUIT DIAGNOSIS >

[QR25DE]

P0300, P0301, P0302, P0303, P0304 MISFIRE

b. Start engine and drive the vehicle under similar conditions to (1st trip) Freeze Frame Data for a certain

time. Refer to the table below.

Hold the accelerator pedal as steady as possible.

Similar conditions to (1st trip) Freeze Frame Data mean that the following conditions should be satisfied at

the same time.

Driving time varies according to the engine speed in the freeze frame data.

WITH GST

Follow the procedure “WITH CONSULT” above.

Diagnosis Procedure

INFOID:0000000009480910

CHECK FOR INTAKE AIR LEAK AND PCV HOSE

1. Start engine and run it at idle speed.

2. Listen for the sound of the intake air leak.

3. Check PCV hose connection.
OK or NG

>> GO TO 2.

>> Discover air leak location and repair.

CHECK FOR EXHAUST SYSTEM CLOGGING

Stop engine and visually check exhaust tube, three way catalyst and muffler for dents.
OK or NG

>> GO TO 3.

>> Repair or replace it.

PERFORM POWER BALANCE TEST

With CONSULT

1. Perform “POWER BALANCE” in “ACTIVE TEST” mode.

2. Is there any cylinder which does not produce a momentary engine speed drop?

Without CONSULT

Engine speed

Engine speed in the freeze frame data

± 400 rpm

Vehicle speed

Vehicle speed in the feaze frame data

± 10 km/h (6 MPH)

Engine coolant temperature (T)
condition

When the freeze frame data shows lower than 70

°C (158 °F),

T should be lower than 70

°C (158 °F).

When the freeze frame data shows higher than or equal to 70

°C (158 °F),

T should be higher than or equal to 70

°C (158 °F).

Engine speed

Time

Around 1,000 rpm

Approximately 10 minutes

Around 2,000 rpm

Approximately 5 minutes

More than 3,000 rpm

Approximately 3.5 minutes

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