Inspection Procedure

HINT:

If any DTCs other than misfire DTCs are output, troubleshoot those DTCs first.
Read freeze frame data using the intelligent tester. The ECM (Included in HV control ECU) records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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 freeze frame data.
The misfire still cannot be reproduced even though the conditions stored in the freeze frame data have been duplicated, one of the following factors is considered to be a possible cause of the problem:
1. The fuel tank is low full.
2. Improper fuel is used.
3. The spark plugs have been contaminated.
4. The problem is complex.
After finishing repairs, check the misfire counts of the cylinders (CYL #10, #20, #30, #40, #50 and #60).
Be sure to confirm that no misfiring cylinder DTCs are set again by conducting the confirmation driving pattern, after repairs.
For 6 and 8 cylinder engines, the ECM (Included in HV control ECU) 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:
1. Clear the DTCs (See DTC CHECK / CLEAR ).
2. Start the engine and conduct the confirmation driving pattern.
3. Read the misfiring rates of each cylinder or DTC(s) using the tester.
4. Repair the cylinder(s) that has a high misfiring rate or is indicated by the DTC.
5. 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 (167°F), misfires have occurred only while warming up the engine.

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

Connect the intelligent tester to the DLC3.
Turn the ignition switch to the ON position.
Turn the tester ON.
Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
Read the DTCs.

Result

RESULT REFERENCE

Display (DTC output)	Proceed to
P0300, P0301, P0302, P0303, P0304, P0305 and/or P0306	A
P0300, P0301, P0302, P0303, P0304, P0305 and/or P0306 and other DTCs	B

HINT:

If any DTCs other than P0300, P0301, P0302, P0303, P0304, P0305 and P0306 are output, troubleshoot those DTCs first.

B: GO TO DTC CHART

A: Go to next step

READ VALUE USING INTELLIGENT TESTER (MISFIRE RPM AND MISFIRE LOAD)
1. Connect the intelligent tester to the DLC3.
2. Put the engine in inspection mode (See INSPECTION MODE PROCEDURE ).
3. Turn the ignition switch to the ON position and turn the tester ON.
4. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / MISFIRE / MISFIRE RPM and MISFIRE LOAD.
5. Read and note the MISFIRE RPM and MISFIRE LOAD (engine load) values.
HINT:

The MISFIRE RPM and MISFIRE LOAD indicate the vehicle conditions under which the misfire occurred.
CHECK PCV HOSE CONNECTIONS
OK: PCV hose is connected correctly and is not damaged.

NG: REPAIR OR REPLACE PCV HOSE

OK: Go to next step

CHECK MISFIRE COUNT (CYL #1, #2, #3, #4, #5 AND #6)

Connect the intelligent tester to the DLC3.
Put the engine in inspection mode (See INSPECTION MODE PROCEDURE ).
Turn the tester ON.
Clear the DTCs.
Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / MISFIRE / CYL #1, #2, #3, #4, #5 and #6.
Start the engine.
Read each value of CYL #1 to #6 displayed on the tester. If no misfire counts occur in any cylinders, perform the following conditions:
1. Shift the gear selector lever to the D position.
2. Repeat steps (e) to (g) above.
3. Check the CYL #1 to #6.
4. If misfire counts are still not displayed, perform steps (h) and (i) and then check the misfire counts again.
Drive the vehicle with MISFIRE RPM and MISFIRE LOAD noted in step 10.
Read the CYL #1 to #6 or DTCs displayed on the tester.

Result

RESULT REFERENCE

Misfire count	Proceed to
1 or 2 cylinders have misfire counts	A
3 cylinders or more have misfire counts	B

B: GO TO step 11

A: Go to next step

CHECK SPARK PLUG

Remove the ignition coil and the spark plug of the misfiring cylinder.
Measure the spark plug electrode gap.
Standard:

Between 1.0 mm and 1.1 mm (0.039 in. and 0.043 in.)
Check the electrode for carbon deposits.

Recommended spark plug:

RECOMMENDED SPARK PLUG

Manufacture	Product
DENSO	SK20R11
NGK	IFR6A11

NOTE: If the electrode gap is larger than standard, replace the spark plug. Do not adjust the electrode gap.

NG: REPLACE SPARK PLUG

Fig 1: Measuring Spark Plug Electrode Gap

OK: Go to next step

CHECK FOR SPARKS AND IGNITION
1. Disconnect the injector connectors, in order to prevent the engine from starting.
2. Install the spark plug to the ignition coil.
3. Attach the spark plug assembly to the cylinder head cover.
4. Crank the engine for less than 2 seconds and check the spark.
  OK: Sparks jump across electrode gap.
5. Reconnect the injector connectors.
NG: GO TO step 8

OK: Go to next step
CHECK CYLINDER COMPRESSION PRESSURE OF MISFIRING CYLINDER
1. Measure the cylinder compression pressure of the misfiring cylinder (See ON-VEHICLE INSPECTION ).
  Minimum pressure:
  
  0.74 MPa (7.5 kgf/cm ² , 107 psi)
  
  Difference between each cylinder:
  
  100 kPa (1.0 kgf/cm ² , 15 psi)
OK: GO TO step 9

NG: CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION
CHANGE NORMAL SPARK PLUG AND CHECK SPARK OF MISFIRING CYLINDER
1. Change the installed spark plug to a spark plug that functions normally.
2. Perform a spark test.
  CAUTION: Always disconnect all injector connectors.
  
  NOTE: 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.
    OK: Sparks jump across electrode gap.
NG: REPLACE IGNITION COIL ASSEMBLY THEN CONFIRM THAT THERE IS NO MISFIRE

OK: REPLACE SPARK PLUG
CHECK FUEL INJECTOR OF MISFIRING CYLINDER
1. Check the injector injection (whether fuel volume is high or low, and whether injection pattern is poor).
  Standard:
  
  13 cm ³ (0.8 cu in.) or less
NG: REPLACE FUEL INJECTOR ASSEMBLY

OK: Go to next step
CHECK VALVE CLEARANCE OF MISFIRING CYLINDER
1. Check the valve clearance of the misfiring cylinder (See VALVE CLEARANCE ).
NG: ADJUST VALVE CLEARANCE

OK: Go to next step
CHECK AIR INDUCTION SYSTEM
1. Check the air induction system for vacuum leakage.
  OK: No leakage from air induction system.
NG: REPAIR OR REPLACE AIR INDUCTION SYSTEM

OK: Go to next step
CHECK VALVE TIMING
1. Remove the cylinder head cover.
2. Turn the crankshaft pulley, and align its groove with timing mark "0" of the timing chain cover.
3. Check that the timing marks of the camshaft timing gears are aligned with the timing marks of the No. 3 timing belt cover as shown in the illustration.
  If not, turn the crankshaft 1 revolution (360°) and align the marks as above.
  
  OK: The timing marks on the camshaft timing gears are aligned as shown in illustration.
4. Reinstall the cylinder head cover.
NG: ADJUST VALVE TIMING

Fig 2: Identifying Matchmarks Of Camshaft Pulley And Camshaft Bearing Cap
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: Go to next step
CHECK FUEL PRESSURE
1. Check the fuel pressure (See ON-VEHICLE INSPECTION ).
  Standard:
  
  304 to 343 kPa (3.1 to 3.5 kgf/cm ² , 44.1 to 49.7 psi)
NG: CHECK AND REPLACE FUEL PUMP, PRESSURE REGULATOR, FUEL PIPE LINE AND FILTER

OK: Go to next step
READ VALUE USING INTELLIGENT TESTER (COOLANT TEMP)
1. Connect the intelligent tester to the DLC3.
2. Put the engine in inspection mode (See INSPECTION MODE PROCEDURE ).
3. Start the engine.
4. Turn the tester ON.
5. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / COOLANT TEMP.
6. 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 95°C (167°F and 203°F).
NG: REPLACE E.F.I. ENGINE COOLANT TEMPERATURE SENSOR

OK: Go to next step
READ VALUE USING INTELLIGENT TESTER (MAF)
1. Connect the intelligent tester to the DLC3.
2. Turn the tester ON.
3. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / MAF.
4. Read the MAF with the engine stopped.
  Standard:
  
  MAF while engine stopped: 0.54 g/s or less
5. Put the engine in inspection mode (See INSPECTION MODE PROCEDURE ).
6. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / MAF and COOLANT TEMP.
7. Allow the engine to idle until the COOLANT TEMP reaches 75°C (167°F) or more.
8. Read the MAF with the engine in an idling condition and at an engine speed of 2,500 rpm.
  Standard:
  
  MAF while engine idling:
  
  Between 2.0 g/s and 4.3 g/s (shift position: N, A/ C: OFF).
  
  MAF at an engine speed of 2,500 rpm:
  
  Between 12.1 g/s and 18.2 g/s (shift position: N, A/C: OFF).
NG: REPLACE MASS AIR FLOW METER

OK: CHECK FOR INTERMITTENT PROBLEMS