
2GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEMES–203
ES
(a) Remove the FUEL PUMP relay from the engine room 
junction block. 
(b) Disconnect the E11 ECM connector. 
(c) Measure the resistance according to the value(s) in the 
table below.
Standard resistance
(d) Reconnect the ECM connector.
(e) Reinstall the FUEL PUMP relay.
NG
OK
3CHECK HARNESS AND CONNECTOR (FUEL PUMP RELAY - ECM)
A163154E03
Tester Connection Specified Condition
FUEL PUMP relay terminal 1 - FPR (E11-30) Below 1 
FUEL PUMP relay terminal 1 or FPR (E11-30) - Body 
Ground10 k or higher
REPAIR OR REPLACE HARNESS OR 
CONNECTOR (FUEL PUMP RELAY - ECM)
REPLACE ECM (See page ES-498) 

ES–2042GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEM
ES
DESCRIPTION
When the engine misfires, high concentrations of hydrocarbons (HC) enter the exhaust gas. High HC 
concentration levels can cause increase in exhaust emission levels. Extremely high concentrations of HC 
can also cause increases in the Three-Way Catalytic Converter (TWC) temperature, which may cause 
damage to the TWC. To prevent this increase in emissions and to limit the possibility of thermal damage, 
the ECM monitors the misfire rate. When the temperature of the TWC reaches the point of thermal 
degradation, the ECM blinks the MIL. To monitor misfires, the ECM uses both the VVT sensor and the 
Crankshaft Position (CKP) sensor. The VVT sensor is used to identify any misfiring cylinders and the CKP 
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, the ECM illuminates the MIL and sets a DTC.
DTC P0300 Random / Multiple Cylinder Misfire Detected
DTC P0301 Cylinder 1 Misfire Detected
DTC P0302 Cylinder 2 Misfire Detected
DTC P0303 Cylinder 3 Misfire Detected
DTC P0304 Cylinder 4 Misfire Detected
DTC P0305 Cylinder 5 Misfire Detected
DTC P0306 Cylinder 6 Misfire Detected
DTC No. DTC Detection Condition Trouble Area
P0300Simultaneous misfiring of several cylinders occurs and one of 
following conditions below is detected (2 trip detection logic):
• High temperature misfire occurs in Three-Way Catalytic 
Converter (TWC) (MIL blinks)
• Emission deterioration misfire occurs (MIL illuminates)• Open or short in engine wire harness
• Connector connection
• Vacuum hose connections
• Ignition system
• Injector
• Fuel pressure
• Mass Air Flow (MAF) meter
• Engine Coolant Temperature (ECT) sensor
• Compression pressure
• Valve clearance
• Valve timing
• PCV valve and hose
• PCV hose connections
• Intake system
•ECM P0301
P0302
P0303
P0304
P0305
P0306Misfiring of specific cylinder occurs and one of following 
conditions below is detected (2 trip detection logic):
• High temperature misfire occurs in Three-Way Catalytic 
Converter (TWC) (MIL blinks)
• Emission deterioration misfire occurs (MIL illuminates)
A093767E07 

2GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEMES–205
ES
When multiple DTCs for misfiring cylinders are set, but DTC P0300 is not set, it indicates that misfires 
have been detected in different cylinders at different times. DTC P0300 is only set 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 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 1,000 crankshaft revolutions) occurs a 
total of 4 times.
The ECM flashes the MIL and sets a DTC when either one of the following conditions, which could cause 
the Three-Way Catalytic Converter (TWC) damage, is detected (2 trip detection logic).
• At a high engine rpm, a catalyst damage misfire, which monitored every 200 crankshaft revolutions, 
occurs once.
• At a normal engine rpm, a catalyst damage misfire, which monitored every 200 crankshaft revolutions, 
occurs 3 times.
HINT:
If a catalyst damage misfire occurs, the ECM informs the driver by flashing the MIL.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
Misfire:
Monitor period of emission-related-misfire:
Related DTCsP0300: Multiple cylinder misfire
P0301: Cylinder 1 misfire
P0302: Cylinder 2 misfire
P0303: Cylinder 3 misfire
P0304: Cylinder 4 misfire
P0305: Cylinder 5 misfire
P0306: Cylinder 6 misfire
Required Sensors / Components (Main) Injector, Ignition coil, Spark plug
Required Sensors / Components (Related)Crankshaft, Camshaft, Engine coolant temperature and intake air temperature 
sensors and Mass air flow meter
Frequency of Operation Continuous
Duration1000 to 4000 crankshaft revolutions: Emission related misfire
200 to 600 crankshaft revolutions: Catalyst damaged misfire
MIL Operation2 driving cycles: Emission related misfire
MIL flashes immediately: Catalyst damaged misfire
Sequence of Operation None
The monitor will run whenever these DTCs are not 
presentP0100, P0101, P0102, P0103 (MAF Sensor), P0110, P0112, P0113 (IAT Sensor), 
P0115, P0116, P0117, P0118 (ECT Sensor), P0120, P0121, P0122, P0123, P0220,  
P0222, P0223, P2135 (TP Sensor), P0125 (Insufficient ECT for Closed Loop), 
P0327, P0328, P0332, P0333 (Knock Sensor), P0335 (CKP Sensor), P0340, (CMP 
Sensor), P0500 (VSS)
Battery voltage 8 V or more
VVT system No operate by scan tool
Engine RPM 450 to 6500 rpm
Either of the following conditions is met Condition (a) or (b)
(a) Engine start ECT More than -7
C (19F)
(b) ECT More than 20
C (68F)
Fuel-cut OFF
First 1000 revolutions after engine start, or check mode Crankshaft 1000 revolutions 

ES–2082GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEM
ES
7. Drive the vehicle several times with the conditions, such as engine rpm and engine load, shown in 
MISFIRE RPM and MISFIRE LOAD in the Data List.
HINT:
• In order to store misfire DTCs, it is necessary to operate the vehicle for the period of time shown in 
the table below, using the MISFIRE RPM and MISFIRE LOAD in the Data List.
8. Check whether misfires have occurred by checking DTCs and freeze frame data. 
HINT:
Do not turn the ignition switch off until the stored 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 
will be erased.
9. Record the DTC(s), freeze frame data and misfire counts.
10.Turn the ignition switch OFF and wait for at least 5 seconds.
INSPECTION PROCEDURE
HINT:
• If any DTCs other than misfire DTCs are output, troubleshoot those DTCs first.
• Read freeze frame data using the intelligent tester or Techstream. Freeze frame data records the 
engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help 
determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel 
ratio was lean or rich, and other data from the time the malfunction occurred.
• 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:
(a) There was insufficient fuel volume in the tank.
(b) Improper fuel is used.
(c) The spark plugs have been contaminated.
• After finishing repairs, check the misfire counts of the cylinders (CYL #1, #2, #3, #4, #5, #6).
• Be sure to confirm that no misfiring cylinder DTCs are set again by conducting the confirmation driving 
pattern after finishing repairs.
• For 6 and 8 cylinder engines, the ECM intentionally does not set the specific misfiring cylinder DTCs at 
high engine RPM. If misfires occur only in high engine RPM areas, only DTC P0300 is set.
In the event of DTC P0300 being present, perform the following operations:
(a) Clear the DTC (See page ES-39).
(b) Start the engine and conduct the confirmation driving pattern.
(c) Read the misfiring rates of each cylinder or DTC(s) using the tester.
(d) Repair the cylinder(s) that has a high misfiring rate or is indicated by the DTC.
(e) After finishing repairs, conduct the confirmation driving pattern again, in order to verify that DTC 
P0300 is not set.
• When one of SHORT FT #1, LONG FT #1, SHORT FT #2 or LONG FT #2 in the freeze frame data is 
outside the range of +/-20%, the air-fuel ratio may be Rich (-20% or less) or Lean (+20% or more).
• When the COOLANT TEMP in the freeze frame data is less than 75
C (167F), the misfire have 
occurred only while warming up the engine.
Engine RPM Duration
Idling 3.5 minutes or more
1000 3 minutes or more
2000 1.5 minutes or more
3000 1 minute or more 

2GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEMES–213
ES
Cylinder No. 5
Cylinder No. 6
NG
OK
(a) Turn the ignition switch to the ON position.
(b) Measure the voltage according to the value(s) in the 
table below.
Standard voltage
NG
OK
(a) Check the injector injection (whether fuel volume is high 
or low, and whether injection pattern is poor) (See page 
FU-16).
NG
OK
I26-2 - Ground 10 k or higher
I26-1 - #40 (E11-5) Below 1 
Tester Connection Specified Condition
I27-1 - Ground 11 to 14 V
I27-2 - Ground 10 k
 or higher
I27-1 - #50 (E11-6) Below 1 
Tester Connection Specified Condition
I28-1 - Ground 11 to 14 V
I28-2 - Ground 10 k
 or higher
I28-1 - #60 (E11-7) Below 1 
REPAIR OR REPLACE HARNESS OR 
CONNECTOR
Tester Connection Specified Condition
11INSPECT ECM TERMINAL OF MISFIRING CYLINDER (#10, #20, #30, #40, #50 AND /OR #60 
VOLTAGE)
A162489E04
Tester Connection Specified Condition
#10 (E11-2) - E01 (E9-7) 9 to 14 V
#20 (E11-3) - E01 (E9-7) 9 to 14 V
#30 (E11-4) - E01 (E9-7) 9 to 14 V
#40 (E11-5) - E01 (E9-7) 9 to 14 V
#50 (E11-6) - E01 (E9-7) 9 to 14 V
#60 (E11-7) - E01 (E9-7) 9 to 14 V
REPAIR OR REPLACE HARNESS OR 
CONNECTOR (BATTERY - ECM)
12CHECK FUEL INJECTOR OF MISFIRING CYLINDER
REPLACE FUEL INJECTOR ASSEMBLY (See 
page FU-16) 

ES–2142GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEM
ES
(a) Check the intake system for vacuum leakage (See page 
IT-1).
OK:
No leakage from intake system.
NG
OK
NG
OK
(a) Check the fuel pressure (See page FU-7).
NG
OK
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn the tester on.
(d) Select the following menu items: DIAGNOSIS / 
ENHANCED OBD II / DATA LIST / PRIMARY / 
COOLANT TEMP.
(e) Read the COOLANT TEMP twice, when the engine is 
both cold and warmed up.
Standard:
With cold engine:
Same as ambient air temperature.
With warm engine:
Between 75
C and 95C (167F and 203F).
NG
OK
(a) Connect the intelligent tester to the DLC3.
13CHECK INTAKE SYSTEM
REPAIR OR REPLACE INTAKE SYSTEM
14CHECK VALVE TIMING (CHECK FOR LOOSE AND JUMPED TEETH ON TIMING CHAIN) 
(See page ES-92)
ADJUST VALVE TIMING
15CHECK FUEL PRESSURE
CHECK AND REPLACE FUEL PUMP, 
PRESSURE REGULATOR, FUEL PIPE LINE 
AND FILTER
16READ VALUE OF INTELLIGENT TESTER (COOLANT TEMP)
REPLACE ENGINE COOLANT 
TEMPERATURE SENSOR
17READ VALUE OF INTELLIGENT TESTER (MASS AIR FLOW METER) 

2GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEMES–215
ES
(b) Turn the ignition switch to the ON position.
(c) Turn the tester on.
(d) Select the following menu items: DIAGNOSIS / 
ENHANCED OBD II / DATA LIST / PRIMARY / MAF and 
COOLANT TEMP.
(e) Allow the engine to idle until the COOLANT TEMP 
reaches 75
C (167F) or more.
(f) Read the MAF with the engine in an idling condition and 
at an engine speed of 2500 rpm.
Standard:
MAF while engine is idling:
Between 1.8 g/s and 4.7 g/s (shift position: N, A/
C: OFF).
MAF at engine speed of 2500 rpm:
Between 7.4 g/s and 18.9 g/s (shift position: N, A/
C: OFF).
NG
OK
(a) Check the intake system for vacuum leakage (See page 
IT-1).
OK:
No leakage from intake system.
NG
OK
NG
OK
(a) Check the fuel pressure (See page FU-7).
NG
OKREPLACE MASS AIR FLOW METER
REPLACE ECM
18CHECK INTAKE SYSTEM
REPAIR OR REPLACE INTAKE SYSTEM
19CHECK VALVE TIMING (CHECK FOR LOOSE AND JUMPED TEETH ON TIMING CHAIN) 
(See page ES-92)
ADJUST VALVE TIMING
20CHECK FUEL PRESSURE
CHECK AND REPLACE FUEL PUMP, 
PRESSURE REGULATOR, FUEL PIPE LINE 
AND FILTER 

2GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEMES–219
ES
OK
(a) Turn the ignition switch to the ON position.
(b) Measure the voltage according to the value(s) in the 
table below.
Standard voltage
NG
OK
(a) Check the injector injection (whether fuel volume is high 
or low, and whether injection pattern is poor) (See page 
FU-16).
NG
OK
(a) Change the installed spark plug to a spark plug that 
functions normally.
(b) Perform a spark test.
CAUTION:
Always disconnect all injector connectors.
NOTICE:
Do not crank the engine for more than 2 seconds.
(1) Install the spark plug to the ignition coil and connect 
the ignition coil connector.
(2) Disconnect the injector connector.
(3) Ground the spark plug.
(4) Check if sparks occur while the engine is being 
cranked.
27INSPECT ECM TERMINAL OF MISFIRING CYLINDER (#10, #20, #30, #40, #50 AND /OR #60 
VOLTAGE)
A162489E04
Tester Connection Specified Condition
#10 (E11-2) - E01 (E9-7) 9 to 14 V
#20 (E11-3) - E01 (E9-7) 9 to 14 V
#30 (E11-4) - E01 (E9-7) 9 to 14 V
#40 (E11-5) - E01 (E9-7) 9 to 14 V
#50 (E11-6) - E01 (E9-7) 9 to 14 V
#60 (E11-7) - E01 (E9-7) 9 to 14 V
REPAIR OR REPLACE HARNESS OR 
CONNECTOR (BATTERY - ECM)
28CHECK FUEL INJECTOR OF MISFIRING CYLINDER
REPLACE FUEL INJECTOR ASSEMBLY
REPLACE ECM
29CHANGE TO NORMAL SPARK PLUG AND CHECK SPARK OF MISFIRING CYLINDER