2Zr-Fe Engine Control. Dtc P0300 Random / Multiple Cylinder Misfire Detected

When the engine misfires, high concentrations of hydrocarbons (HC) enter the exhaust gas. Extremely high hydrocarbon concentration levels can cause an increase in exhaust emission levels. Extremely high concentrations of hydrocarbons can also cause increases in the three-way catalytic converter temperature, which may cause damage to the three-way catalytic converter. To prevent this increase in emissions and to limit the possibility of thermal damage, the ECM monitors the misfire count. When the temperature of the three-way catalytic converter reaches the point of thermal degradation, the ECM blinks the MIL. To monitor misfires, the ECM uses both the camshaft position sensor and the crankshaft position sensor. The camshaft position sensor is used to identify any misfiring cylinders and the crankshaft position sensor is used to measure variations in the crankshaft rotation speed. Misfires are counted when the crankshaft rotation speed variations exceed predetermined thresholds. If the misfire count exceeds the threshold levels, and could cause emission control system performance deterioration, the ECM illuminates the MIL and stores a DTC.

DTC No.	DTC Detection Condition	Trouble Area
P0300	Simultaneous misfiring of several cylinders occurs and one of the following conditions is met (2 trip detection logic). A misfire occurs that may damage the three-way catalytic converter (MIL blinks when detect immediately). An emission deterioration misfire occurs (MIL illuminates).	Open or short in engine wire harness Connector connection Vacuum hose connections Ignition system Fuel injector assembly Fuel pressure Mass air flow meter sub-assembly Engine coolant temperature sensor Compression pressure Valve timing PCV valve and hose PCV hose connections Intake system ECM
P0301 P0302 P0303 P0304	Misfiring of a specific cylinder occurs and one of the following conditions is met (2 trip detection logic). A misfire occurs that may damage the three-way catalytic converter (MIL blinks when detect immediately). An emission deterioration misfire occurs (MIL illuminates).

When DTCs for misfiring cylinders are randomly stored, but DTC P0300 is not stored, it indicates that misfires have been detected in different cylinders at different times. DTC P0300 is only stored when several misfiring cylinders are detected at the same time.

MONITOR DESCRIPTION

The ECM illuminates the MIL and sets a DTC when either one of the following conditions, which could cause emission control system performance deterioration, is detected (2 trip detection logic).

Within the first 1000 crankshaft revolutions of the engine starting, an excessive misfiring rate (approximately 20 to 50 misfires per 1000 crankshaft revolutions) occurs once.
An excessive misfiring rate (approximately 20 to 50 misfires per 1000 crankshaft revolutions) occurs a total of 4 times.

The ECM flashes the MIL (immediate detection logic) and sets a DTC (2 trip detection logic) when either one of the following conditions, which could cause the three-way catalytic converter damage, is detected.

HINT:

If a catalyst damage misfire occurs, the monitor informs the driver by blinking the MIL (1 trip).

In every 200 crankshaft revolutions at a high engine speed, the threshold misfiring percentage is recorded once.
In every 200 crankshaft revolutions at a normal engine speed, the threshold misfiring percentage is recorded 3 times.

Misfire Monitor for Mexico Models
The ECM illuminates the MIL and sets a DTC when either one of the following conditions, which could cause emission deterioration, is detected (2 trip detection logic).
1. Within the first 1000 crankshaft revolutions of the engine starting, an excessive misfiring rate (approximately 1000 misfires per 1000 crankshaft revolutions) occurs once.
2. An excessive misfiring rate (approximately 500 misfires per 1000 crankshaft revolutions) occurs a total of 4 times.
The ECM flashes the MIL (immediate detection logic) and sets a DTC (2 trip detection logic) when the following condition, which could cause the Three-Way Catalytic Converter (TWC) damage, is detected.
1. A catalyst damage misfire, which is monitored every 200 crankshaft revolutions, occurs 3 times.

MONITOR STRATEGY

Related DTCs	P0300: Multiple cylinder misfire P0301: Cylinder 1 misfire P0302: Cylinder 2 misfire P0303: Cylinder 3 misfire P0304: Cylinder 4 misfire
Required Sensors/Components (Main)	Crankshaft position sensor Camshaft position sensor
Required Sensors/Components (Related)	Engine coolant temperature Intake air temperature sensor Mass air flow meter
Frequency of Operation	Continuous
Duration	1000 crankshaft revolutions (soon after engine is started: 1 time, other 4 times) (Emission-related misfire) 200 crankshaft revolutions (1 or 3 times) (Catalyst-damaging misfire)
MIL Operation	2 driving cycles: Emission related misfire MIL flashes immediately: Catalyst damaging misfire
Sequence of Operation	None

TYPICAL ENABLING CONDITIONS

Misfire
Monitor runs whenever following DTCs not present	P0016 (VVT System - Misalignment) P0017 (Exhaust VVT System - Misalignment) P0102, P0103 (Mass Air Flow Meter) P0112, P0113 (Intake Air Temperature Sensor) P0115, P0117, P0118 (Engine Coolant Temperature Sensor) P0120, P0121 P0122, P0123, P0220, P0222, P0223, P2135 (Throttle Position Sensor) P0125 (Insufficient Engine Coolant Temperature for Closed Loop Fuel Control) P0327, P0328 (Knock Sensor) P0335 (Crankshaft Position Sensor) P0340, P0342, P0343 (Camshaft Position Sensor) P0351, P0352, P0353, P0354 (Igniter) P0500 (Vehicle Speed Sensor)
Battery voltage	8 V or more
VVT system	Not operated by scan tool
Engine speed	450 to 6400 rpm
Either of following conditions (a) or (b) met	-
(a) Engine coolant temperature at engine start	More than -7°C (19°F)
(b) Engine coolant temperature	More than 20°C (68°F)
Fuel cut	Off

Monitor Period of Emission-Related Misfire
First 1000 revolutions after engine start, or Check Mode	Crankshaft 1000 revolutions
Except above	Crankshaft 1000 revolutions x 4

Monitor Period of Catalyst Damaging Misfire (MIL Blinks)
All of following conditions 1, 2, 3 and 4 met	Crankshaft 200 revolutions x 3
Except above (MIL blinks immediately)	Crankshaft 200 revolutions
1. Driving cycles	1st
2. Check mode	Off
3. Engine speed	Less than 2450 rpm
4. Intake air amount per revolution	Less than 0.7 g/rev

Misfire: for Mexico models
The monitor will run whenever these DTCs are not present	P0016 (VVT System - Misalignment) P0017 (Exhaust VVT System - Misalignment) P0102, P0103 (Mass Air Flow Meter) P0112, P0113 (Intake Air Temperature Sensor) P0115, P0117, P0118 (Engine Coolant Temperature Sensor) P0120, P0121 P0122, P0123, P0220, P0222, P0223, P2135 (Throttle Position Sensor) P0327, P0328 (Knock Sensor) P0335 (Crankshaft Position Sensor) P0340, P0342, P0343 (Camshaft Position Sensor) P0351, P0352, P0353, P0354 (Igniter) P0500 (Vehicle Speed Sensor)
Battery voltage	8 V or more
VVT system	Not operated by scan tool
Engine speed	450 to 4500 rpm
Engine coolant temperature sensor	More than 65°C (149°F)
Fuel cut	Off

Monitor period of emission-related-misfire: for Mexico models
First 1000 revolutions after engine start, or check mode	Crankshaft 1000 revolutions
Except above	Crankshaft 1000 revolutions x 4

Monitor period of catalyst-damaged-misfire (MIL blinks): for Mexico models
All of following conditions 1, 2 and 3 met	Crankshaft 200 revolutions x 3
1. Driving cycles	1st
2. Check mode	Off
Except above	Crankshaft 200 revolutions

TYPICAL MALFUNCTION THRESHOLDS

Monitor Period of Emission Related Misfire
Misfire rate	1% or more

Monitor Period of Catalyst Damaging Misfire (MIL Blinks)
Number of misfire per 200 revolutions	124 or more (varies with intake air amount per engine speed)

Monitor period of emission-related-misfire: for Mexico models
Misfire rate	50.0 % or more: for 1st 2000 revolutions 25.0 % or more: after 1st 2000 revolutions

Monitor period of catalyst-damaged-misfire (MIL blinks): for Mexico models
Number of misfire per 200 revolutions	94 or more (varies with intake air amount and engine speed)
Paired cylinder misfire (MIL blinks immediately)	Detected

MONITOR RESULT

Refer to Checking Monitor Status (Link).

CONFIRMATION DRIVING PATTERN

Connect the Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Record the DTC(s) and freeze frame data.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Using the Techstream, switch the ECM from normal mode to check mode (COROLLA_ZRE142 RM000000PDL0PIX.html).
Read the misfire counts of each cylinder, Cylinder #1 Misfire Count to Cylinder #4 Misfire Count, with the engine idling. If any misfire count is displayed, skip the following confirmation driving pattern.
Drive the vehicle so that the vehicle conditions displayed in Misfire RPM and Misfire Load of the Data List are the same as the freeze frame data. Perform this step several times.

HINT:
In order to store misfire DTCs, it is necessary to operate the vehicle for the period of time shown in the table below, confirm the Misfire RPM and Misfire Load in the Data List.

Engine speed
Duration
Idling
8.0 minutes or more
1000
4.5 minutes or more
2000
2.5 minutes or more
3000
1.5 minutes or more
Check whether misfires have occurred by checking DTCs and freeze frame data.
HINT:
Do not turn the ignition switch off until the output DTC(s) and freeze frame data have been recorded. When the ECM returns to normal mode (default), the stored DTC(s), freeze frame data and other data are cleared.
Record the DTC(s), freeze frame data and misfire counts.
Turn the ignition switch off and wait for at least 30 seconds.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).

WIRING DIAGRAM

Refer to DTC P0102 (COROLLA_ZRE142 RM000000U5B0NJX_07.html).
Refer to Fuel Injector Circuit (COROLLA_ZRE142 RM000000ZRM0FVX_02.html).

INSPECTION PROCEDURE

HINT:

Check the "Fuel Cut Elps Time" in the Data List or the Freeze Frame Data.
If the elapsed time is over 0 seconds, then the engine speed is high (engine speed at which fuel cut occurs + 500 rpm).
When this has happened, there is the possibility that the valve rocker arm will become loose and a fire could start, so check that the valve rocker arm is properly attached (COROLLA_ZRE142 RM000002XA8027X.html).
By clearing the DTC, "Fuel Cut Elps Time" will be cleared.
If any DTCs other than misfire DTCs are output, troubleshoot those DTCs first.
Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
If the misfire does not recur when the vehicle is brought to the workshop, reproduce the conditions stored in the ECM as freeze frame data.
If the misfire still cannot be reproduced even though the conditions stored in the ECM as freeze frame data have been reproduced, one of the following factors is considered to be a possible cause of the problem:

There was insufficient fuel in the tank.
Improper fuel is used.
The spark plugs have been contaminated.
The problem requires further diagnosis.

After finishing repairs, check the misfire counts of the cylinders Cylinder #1 Misfire Count to Cylinder #4 Misfire Count.
Be sure to confirm that no misfiring cylinder DTCs are set again by conducting the confirmation driving pattern after finishing repairs.
When one of Short FT #1 or Long FT #1 in the freeze frame data is outside the range of +/-15%, the air fuel ratio may be Rich (-15% or less) or Lean (+15% or more).
When the Coolant Temp in the freeze frame data is less than 75°C (167°F), the misfire have occurred only while warming up the engine.
An extremely imbalanced drive wheel which causes body vibration may cause misfire DTCs detected.

1.CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO MISFIRE DTCS)

Connect the Techstream to the DLC3.

Turn the ignition switch to ON.

Turn the Techstream on.

Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

Read the DTCs.

Result:

Result
Proceed to
DTC P0300, P0301, P0302, P0303 and/or P0304 is output
A
DTC P0300, P0301, P0302, P0303 and/or P0304 and other DTCs are output
B

HINT:

If any DTCs other than P0300, P0301, P0302, P0303 and P0304 are output, troubleshoot those DTCs first.

GO TO DTC CHART (COROLLA_ZRE142 RM000000PDF0G8X.html)

A

2.CHECK PCV HOSE CONNECTIONS

Check the PCV hose connections (COROLLA_ZRE142 RM000002WZK01NX.html).
OK:
PCV hose is connected correctly and is not damaged.

REPAIR OR REPLACE PCV HOSE

OK

3.READ VALUE USING TECHSTREAM (MISFIRE RPM AND MISFIRE LOAD)

Connect the Techstream to the DLC3.

Turn the ignition switch to ON.

Turn the Techstream on.

Enter the following menus: Powertrain / Engine and ECT / Data List / Misfire RPM and Misfire Load.

Read and note the Misfire RPM and Misfire Load values.
HINT:
The Misfire RPM and Misfire Load values indicate the vehicle conditions under which the misfire occurred.

NEXT

4.READ VALUE USING TECHSTREAM (CATALYST OT MF F/C)

Connect the Techstream to the DLC3.

Turn the ignition switch to ON.

Turn the Techstream on.

Enter the following menus: Powertrain / Engine and ECT / Data List / Catalyst OT MF F/C.

Read the value displayed on the Techstream.

Result:

Data List
Techstream Display
Proceed to
Catalyst OT MF F/C
Avail
A
Not Avl
B

Go to step 6

A

5.PERFORM ACTIVE TEST USING TECHSTREAM (PROHIBIT THE CATALYST OT MISFIRE PREVENT F/C)

Connect the Techstream to the DLC3.

Turn the ignition switch to ON.

Turn the Techstream on.

Enter the following menus: Powertrain / Engine and ECT / Active Test / Prohibit the Catalyst OT Misfire Prevent F/C.

Perform the Active Test.
NOTICE:
When performing the Active Test, make sure the vehicle is stopped and the engine is either idling or being revved at 3000 rpm or less.

NEXT

6.READ VALUE USING TECHSTREAM (CYLINDER #1, #2, #3 AND #4 MISFIRE COUNT)

Connect the Techstream to the DLC3.

Turn the ignition switch to ON.

Turn the Techstream on.

Clear the DTCs (COROLLA_ZRE142 RM000000PDK0ZAX.html).

Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Cylinder #1 (to #4) Misfire Count.

Allow the engine to idle.

Read each value for Cylinder #1 (to #4) Misfire Count displayed on the Techstream. If no misfire counts occur in any cylinders, perform procedure [A] and [B], and then check the misfire counts again.

Drive the vehicle with the Misfire RPM and Misfire Load noted in the "Read Value Using Techstream (Misfire RPM And Misfire Load)" procedure above [A].

Read the Cylinder #1 Misfire Count to Cylinder #6 Misfire Count or DTCs displayed on the Techstream [B].

Result
Result
Proceed to
Most misfires occur in only 1 or 2 cylinders
A
3 cylinders or more have equal misfire counts
B

Result
Result	Proceed to
Most misfires occur in only 1 or 2 cylinders	A
3 cylinders or more have equal misfire counts	B

HINT:

If it is difficult to reproduce misfires for each cylinder, check the Data List item called Misfire Margin. Try to find vehicle driving conditions that lower the Misfire Margin value. Values above 30% are considered normal.
If the freeze frame data record of the engine coolant temperature is less than 75°C (167°F), the misfire may be detected only when the engine is cold.
If the freeze frame data record of the Engine Run Time is below 120 seconds, the misfire may be detected immediately after the engine is started.

Go to step 19

A

7.INSPECT SPARK PLUG

Inspect the spark plug of misfiring cylinder (COROLLA_ZRE142 RM000001QVP061X_01_0003.html).

REPLACE SPARK PLUG (COROLLA_ZRE142 RM00000304Q017X.html)

OK

8.CHECK FOR SPARK (SPARK TEST)

Perform a spark test (COROLLA_ZRE142 RM000001QVP061X_01_0001.html).
HINT:
If the result of the spark test is normal, proceed to the next step.

NEXT

9.CHECK CYLINDER COMPRESSION PRESSURE

Measure the cylinder compression pressure of the misfiring cylinder (COROLLA_ZRE142 RM000002ZLZ050X_01_0010.html).

CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

OK

10.CHECK FUEL INJECTOR ASSEMBLY (POWER SOURCE)

Corolla. Zre142 Aze141.2Zr-Fe Engine Control.Sfi System.
Dtc
P0300 Random / Multiple Cylinder Misfire Detected

Disconnect the fuel injector assembly connectors.

Turn the ignition switch to ON.

Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
B9-1 - Body ground	Ignition switch ON	11 to 14 V
B10-1 - Body ground	Ignition switch ON	11 to 14 V
B11-1 - Body ground	Ignition switch ON	11 to 14 V
B12-1 - Body ground	Ignition switch ON	11 to 14 V

Turn the ignition switch off.

Reconnect the fuel injector assembly connectors.

GO TO FUEL INJECTOR CIRCUIT (COROLLA_ZRE142 RM000000ZRM0FVX.html)

OK

11.CHECK HARNESS AND CONNECTOR (ECM - FUEL INJECTOR)

Disconnect the fuel injector assembly connectors.

Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Open):

Tester Connection	Condition	Specified Condition
B9-2 - B31-86 (#10)	Always	Below 1 Ω
B10-2 - B31-85 (#20)	Always	Below 1 Ω
B11-2 - B31-84 (#30)	Always	Below 1 Ω
B12-2 - B31-83 (#40)	Always	Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection	Condition	Specified Condition
B9-2 or B31-86 (#10) - Body ground	Always	10 kΩ or higher
B10-2 or B31-85 (#20) - Body ground	Always	10 kΩ or higher
B11-2 or B31-84 (#30) - Body ground	Always	10 kΩ or higher
B12-2 or B31-83 (#40) - Body ground	Always	10 kΩ or higher

Reconnect the fuel injector assembly connectors.

Reconnect the ECM connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - FUEL INJECTOR)

OK

12.CHECK FUEL INJECTOR OF MISFIRING CYLINDER

Check the injector injection (whether fuel volume is high or low, and whether injection pattern is poor) (COROLLA_ZRE142 RM000001EDQ04ZX.html).

REPLACE FUEL INJECTOR (COROLLA_ZRE142 RM000001EDS05LX.html)

OK

13.CHECK INTAKE SYSTEM

Check the intake system for vacuum leaks (COROLLA_ZRE142 RM000003410016X.html).
OK:
No leaks in intake system.

REPAIR OR REPLACE INTAKE SYSTEM

OK

14.CHECK FUEL PRESSURE

Check the fuel pressure (COROLLA_ZRE142 RM000001IQZ09UX_01_0002.html).

Go to step 36

OK

15.READ VALUE USING TECHSTREAM (COOLANT TEMP)

Connect the Techstream to the DLC3.

Turn the ignition switch to ON.

Turn the Techstream on.

Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.

Read the Coolant Temp twice, when the engine is both cold and warmed up.
Standard value:
With cold engine: Same as ambient air temperature.
With warm engine: Between 75 and 100°C (167 and 212°F).

REPLACE ENGINE COOLANT TEMPERATURE SENSOR (COROLLA_ZRE142 RM0000030LG014X.html)

OK

16.READ VALUE USING TECHSTREAM (MAF)

Connect the Techstream to the DLC3.

Turn the ignition switch to ON.

Turn the Techstream on.

Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF, Coolant Temp and Engine Speed.

Allow the engine to idle until Coolant Temp reaches 75°C (167°F) or higher.

Read MAF with the engine speed at 3000 rpm.
Standard:
Between 5 and 10 gm/s (Shift lever: Neutral; A/C: Off).

Go to step 31

OK

17.ADJUST VALVE TIMING

HINT:

There are no marks on the cylinder head to match-up for the purpose of checking valve timing. Valve timing can only be inspected by lining up the colored plates on the timing chain with the marks on the pulleys. It may be necessary to remove and reinstall the chain to match-up the alignment marks (COROLLA_ZRE142 RM000002XA40C3X.html).

NEXT

18.CHECK WHETHER DTC OUTPUT RECURS

Connect the Techstream to the DLC3.

Turn the ignition switch to ON.

Turn the Techstream on.

Clear the DTCs (COROLLA_ZRE142 RM000000PDK0ZAX.html).

Turn the ignition switch off and wait for at least 30 seconds.

Turn the ignition switch to ON and turn the Techstream on.

Start the engine and warm it up.

Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

Input the DTC: P0300, P0301, P0302, P0303 or P0304.

Check the DTC judgment result.

Result:

Result
Proceed to
NORMAL
(DTC is not output)
A
ABNORMAL
(DTC P0300, P0301, P0302, P0303 or P0304 is output)
B

Go to step 31

END

19.CHECK INTAKE SYSTEM

Check the intake system for vacuum leaks (COROLLA_ZRE142 RM000003410016X.html).
OK:
No leaks in intake system.

REPAIR OR REPLACE INTAKE SYSTEM

OK

20.CHECK FUEL PRESSURE

Check the fuel pressure (COROLLA_ZRE142 RM000001IQZ09UX_01_0002.html).

Go to step 36

OK

21.READ VALUE USING TECHSTREAM (COOLANT TEMP)

Connect the Techstream to the DLC3.

Turn the ignition switch to ON.

Turn the Techstream on.

Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.

Read the Coolant Temp twice, when the engine is both cold and warmed up.
Standard value:
With cold engine: Same as ambient air temperature.
With warm engine: Between 75 and 100°C (167 and 212°F).

REPLACE ENGINE COOLANT TEMPERATURE SENSOR (COROLLA_ZRE142 RM0000030LG014X.html)

OK

22.READ VALUE USING TECHSTREAM (MAF)

Connect the Techstream to the DLC3.

Turn the ignition switch to ON.

Turn the Techstream on.

Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF, Coolant Temp and Engine Speed.

Allow the engine to idle until Coolant Temp reaches 75°C (167°F) or higher.

Read MAF with the engine speed at 3000 rpm.
Standard:
Between 5 and 10 gm/s (Shift lever: Neutral; A/C: Off).

Go to step 31

OK

23.INSPECT SPARK PLUG

Inspect the spark plug of misfiring cylinder (COROLLA_ZRE142 RM000001QVP061X_01_0003.html).

REPLACE SPARK PLUG (COROLLA_ZRE142 RM00000304Q017X.html)

OK

24.CHECK FOR SPARK (SPARK TEST)

Perform a spark test (COROLLA_ZRE142 RM000001QVP061X_01_0001.html).
HINT:
If the result of the spark test is normal, proceed to the next step.

NEXT

25.CHECK CYLINDER COMPRESSION PRESSURE

Measure the cylinder compression pressure of the misfiring cylinder (COROLLA_ZRE142 RM000002ZLZ050X_01_0010.html).

CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

OK

26.CHECK FUEL INJECTOR ASSEMBLY (POWER SOURCE)

Disconnect the fuel injector assembly connectors.

Turn the ignition switch to ON.

Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
B9-1 - Body ground	Ignition switch ON	11 to 14 V
B10-1 - Body ground	Ignition switch ON	11 to 14 V
B11-1 - Body ground	Ignition switch ON	11 to 14 V
B12-1 - Body ground	Ignition switch ON	11 to 14 V

Turn the ignition switch off.

Reconnect the fuel injector assembly connectors.

GO TO FUEL INJECTOR CIRCUIT (COROLLA_ZRE142 RM000000ZRM0FVX.html)

OK

27.CHECK HARNESS AND CONNECTOR (ECM - FUEL INJECTOR)

Disconnect the fuel injector assembly connectors.

Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Open):

Tester Connection	Condition	Specified Condition
B9-2 - B31-86 (#10)	Always	Below 1 Ω
B10-2 - B31-85 (#20)	Always	Below 1 Ω
B11-2 - B31-84 (#30)	Always	Below 1 Ω
B12-2 - B31-83 (#40)	Always	Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection	Condition	Specified Condition
B9-2 or B31-86 (#10) - Body ground	Always	10 kΩ or higher
B10-2 or B31-85 (#20) - Body ground	Always	10 kΩ or higher
B11-2 or B31-84 (#30) - Body ground	Always	10 kΩ or higher
B12-2 or B31-83 (#40) - Body ground	Always	10 kΩ or higher

Reconnect the fuel injector assembly connectors.

Reconnect the ECM connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - FUEL INJECTOR)

OK

28.CHECK FUEL INJECTOR OF MISFIRING CYLINDER

Check the injector injection (whether fuel volume is high or low, and whether injection pattern is poor) (COROLLA_ZRE142 RM000001EDQ04ZX.html).

REPLACE FUEL INJECTOR (COROLLA_ZRE142 RM000001EDS05LX.html)

OK

29.ADJUST VALVE TIMING

HINT:

NEXT

30.CHECK WHETHER DTC OUTPUT RECURS

Connect the Techstream to the DLC3.

Turn the ignition switch to ON.

Turn the Techstream on.

Clear the DTCs (COROLLA_ZRE142 RM000000PDK0ZAX.html).

Turn the ignition switch off and wait for at least 30 seconds.

Turn the ignition switch to ON and turn the Techstream on.

Start the engine and warm it up.

Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

Input the DTC: P0300, P0301, P0302, P0303 or P0304.

Check the DTC judgment result.

Result:

Result
Proceed to
ABNORMAL
(DTC P0300, P0301, P0302, P0303 or P0304 is output)
A
NORMAL
(DTC is not output)
B

END

A

31.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER CONNECTOR CONNECTION)

Check the connection and terminal contact pressure of connectors and wire harness between the mass air flow meter and ECM (COROLLA_ZRE142 RM000000UZ30C8X.html).
HINT:
Repair any problems.

NEXT

32.CHECK WHETHER DTC OUTPUT RECURS

Connect the Techstream to the DLC3.

Turn the ignition switch to ON.

Turn the Techstream on.

Clear the DTCs (COROLLA_ZRE142 RM000000PDK0ZAX.html).

Turn the ignition switch off and wait for at least 30 seconds.

Turn the ignition switch to ON and turn the Techstream on.

Start the engine and warm it up.

Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

Input the DTC: P0300, P0301, P0302, P0303 or P0304.

Check the DTC judgment result.

Result:

Result
Proceed to
ABNORMAL
(DTC P0300, P0301, P0302, P0303 or P0304 is output)
A
NORMAL
(DTC is not output)
B

END

A

33.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)

Disconnect the mass air flow meter connector.

Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Open):

Tester Connection
Condition
Specified Condition
B2-5 (VG) - B31-69 (VG)
Always
Below 1 Ω
B2-4 (E2G) - B31-92 (E2G)
Always
Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection
Condition
Specified Condition
B2-5 (VG) or B31-69 (VG) - Body ground
Always
10 kΩ or higher

Reconnect the mass air flow meter connector.

Reconnect the ECM connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER - ECM)

OK

34.REPLACE MASS AIR FLOW METER

Replace the mass air flow meter (COROLLA_ZRE142 RM0000030K7015X.html).
HINT:
If the results of the inspections performed in steps 16 and 22 indicated no problem, proceed to the next step without replacing the mass air flow meter.

NEXT

35.CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

Connect the Techstream to the DLC3.

Turn the ignition switch to ON.

Turn the Techstream on.

Clear the DTCs (COROLLA_ZRE142 RM000000PDK0ZAX.html).

Turn the ignition switch off and wait for at least 30 seconds.

Turn the ignition switch to ON and turn the Techstream on.

Start the engine and warm it up.

Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

Input the DTC: P0300, P0301, P0302, P0303 or P0304.

Check the DTC judgment result.

Result:

Result
Proceed to
NORMAL
(DTC is not output)
A
ABNORMAL
(DTC P0300, P0301, P0302, P0303 or P0304 is output)
B

REPLACE ECM (COROLLA_ZRE142 RM000001CN0030X.html)

END

36.CHECK FUEL LINE

Check the fuel lines for leaks or blockage.

REPAIR OR REPLACE FUEL LINE

REPLACE FUEL PUMP (COROLLA_ZRE142 RM0000022XX05ZX.html)

Engine speed	Duration
Idling	8.0 minutes or more
1000	4.5 minutes or more
2000	2.5 minutes or more
3000	1.5 minutes or more

Result	Proceed to
DTC P0300, P0301, P0302, P0303 and/or P0304 is output	A
DTC P0300, P0301, P0302, P0303 and/or P0304 and other DTCs are output	B

Data List	Techstream Display	Proceed to
Catalyst OT MF F/C	Avail	A
Catalyst OT MF F/C	Not Avl	B

Result	Proceed to
NORMAL (DTC is not output)	A
ABNORMAL (DTC P0300, P0301, P0302, P0303 or P0304 is output)	B