Inspection Procedure

HINT:

If any DTCs other than the misfire DTCs are output, troubleshoot those DTCs first.
Read freeze frame data using the intelligent tester. 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 freeze frame data.
If 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.
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 #1, #2, #3, #4, #5 and #6).
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 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.
If DTC P0300 is present, perform the following operations:
1. Clear the DTC (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 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), the misfires have occurred only while warming up the engine.

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

Connect the intelligent tester to the DLC3.
Turn the ignition switch to the ON position.
Turn the tester on.
Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.

Read the DTCs.

Result

RESULT CHART

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 (See DIAGNOSTIC TROUBLE CODE CHART )

A: Go to Next Step

READ VALUE OF INTELLIGENT TESTER (MISFIRE RPM AND MISFIRE LOAD)
1. Connect the intelligent tester to the DLC3.
2. Turn the ignition switch to the ON position and turn the tester on.
3. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / MISFIRE / MISFIRE RPM and MISFIRE LOAD.
4. Read and note the MISFIRE RPM and MISFIRE LOAD (engine load) values.
  HINT:
  
  The MISFIRE RPM and MISFIRE LOAD values 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 (Procedure "A").
Turn the ignition switch to the ON position (Procedure "B").
Turn the tester on (Procedure "C").
Clear the DTCs (See DTC CHECK/CLEAR ) (Procedure "D").
Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / MISFIRE / CYL #1, #2, #3, #4, #5 and #6 (Procedure "E").
Allow the engine to idle (Procedure "F").
Read each value of CYL #1 to #6 displayed on the tester (Procedure "G").
1. Shift the gear selector lever to the D position.
2. Repeat procedures "E" to "G" above.
3. Check the CYL #1 to #6.
4. If misfire counts are still not displayed, perform procedures "I" and "J" and then check the misfire counts again.
If no misfire counts occur in any cylinders, perform the following operations (Procedure "H").
Drive the vehicle with the MISFIRE RPM and MISFIRE LOAD noted in step 2 (Procedure "I").

Read the CYL #1 to #6 or DTCs displayed on the tester (Procedure "J").

Result

RESULT CHART

Misfire Count	Proceed to
One or two cylinders have misfire counts	A
Three cylinders or more have misfire counts	B

B: Go to step 12

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.

Require spark plug:

SPARK PLUG SPECIFICATION

Manufacturer	Product
DENSO	FK20HR11

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

NG: REPLACE SPARK PLUG

Fig 1: Identifying Spark Plug Electrode Gap

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: Go to Next Step

CHECK FOR SPARKS AND IGNITION (SPARK TEST)
1. Disconnect the injector connectors 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 (ground the spark plug).
4. Crank the engine for less than 2 seconds and check the sparks.
  NOTE: Do not crank the engine for more than 2 seconds.
  
  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 ).
OK: Go to step 9

NG: CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION
CHANGE SPARK PLUG WITH NORMAL ONE AND CHECK FOR SPARKS OF MISFIRING CYLINDER
1. Switch the spark plug with a spark plug that functions normally.
2. Perform the spark test again (refer to step 6).
  OK:
  
  Sparks jump across electrode gap.
NG: REPLACE SPARK PLUG

OK: REPLACE IGNITION COIL ASSEMBLY (See REMOVAL )

INSPECT ECM TERMINAL OF MISFIRING CYLINDER (#10, #20, #30, #40, #50 AND/OR #60 VOLTAGE)

Turn the ignition switch to the ON position.

Measure the voltage between the terminals of the E8 and E7 ECM connectors.

Standard voltage

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Specified Condition
#10 (E7-2) - E01 (E8-7)	9 to 14 V
#20 (E7-3) - E01 (E8-7)	9 to 14 V
#30 (E7-4) - E01 (E8-7)	9 to 14 V
#40 (E7-5) - E01 (E8-7)	9 to 14 V
#50 (E7-6) - E01 (E8-7)	9 to 14 V
#60 (E7-7) - E01 (E8-7)	9 to 14 V

OK: Go to step 11

Fig 2: Identifying ECM Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: Go to Next Step

CHECK HARNESS AND CONNECTOR (INJECTOR - ECM)

Disconnect the injector connector (of the misfiring cylinder).
Disconnect the E7 ECM connector.
Turn the ignition switch to the ON position.

Measure the resistance and voltage between the injector and the ECM connector terminals.

Standard:

Cylinder No. 1

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Specified Condition
I8-1 - Ground	11 to 14 V
I8-2 - Ground	10 kΩ or higher
I8-2-#10 (E7-2)	Below 1 Ω

Cylinder No. 2

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Specified Condition
I9-1 - Ground	11 to 14 V
I9-2 - Ground	10 kΩ or higher
I9-2 - #20 (E7-3)	Below 1 Ω

Cylinder No. 3

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Specified Condition
I10-1 -Ground	11 to 14 V
I10-2 -Ground	10 kΩ or higher
I10-2- #30 (E7-4)	Below 1 Ω

Cylinder No. 4

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Specified Condition
I11-1 -Ground	11 to 14 V
I11-2 -Ground	10 kΩ or higher
I11-2- #40 (E7-5)	Below 1 Ω

Fig 3: Identifying Injector And ECM Connector Terminals

Cylinder No. 5

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Specified Condition
I12-1 - Ground	11 to 14 V
I12-2 - Ground	10 kΩ or higher
I12-2 - #50 (E7-6)	Below 1 Ω

Cylinder No. 6

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Specified Condition
I13-1 - Ground	11 to 14 V
I13-2 - Ground	10 kΩ or higher
I13-2 - #60 (E7-7)	Below 1 Ω

Reconnect the injector connector.
Reconnect the ECM connector.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to Next Step

CHECK FUEL INJECTOR OF MISFIRING CYLINDER
1. Check the injector injection (whether fuel volume is high or low, and whether injection pattern is poor) (See INSPECTION ).
NG: REPLACE FUEL INJECTOR ASSEMBLY (See REMOVAL )

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 (CHECK FOR LOOSE AND JUMPED TEETH ON TIMING CHAIN)
1. Remove the cylinder head covers RH and LH.
2. Turn the crankshaft to align the matchmarks of the crankshaft.
3. Align the notch of the crankshaft pulley to the "0" position.
4. Check if the matchmarks of the camshaft pulley and camshaft bearing cap align.
5. Turn the crankshaft clockwise by 360° if the matchmarks do not align. Check if they align once again.
  OK:
  
  The matchmarks of the camshaft pulley and the camshaft bearing cap align when the notch of the crankshaft pulley is in the "0" position.
NG: ADJUST VALVE TIMING

Fig 4: Identifying Matchmarks Of Crankshaft And Camshaft Pulley
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: Go to Next Step
CHECK FUEL PRESSURE
1. Check the fuel pressure (See ON-VEHICLE INSPECTION ).
NG: CHECK AND REPLACE FUEL PUMP, PRESSURE REGULATOR, FUEL PIPE LINE AND FILTER

OK: Go to Next Step
READ VALUE OF INTELLIGENT TESTER (COOLANT TEMP)
1. Connect the intelligent tester to the DLC3.
2. Turn the ignition switch to the ON position.
3. Turn the tester on.
4. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / COOLANT TEMP.
5. 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 ENGINE COOLANT TEMPERATURE SENSOR (See REMOVAL )

OK: Go to Next Step
READ VALUE OF INTELLIGENT TESTER (MAF)
1. Connect the intelligent tester to the DLC3.
2. Turn the ignition switch to the ON position.
3. Turn the tester on.
4. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / MAF and COOLANT TEMP.
5. Allow the engine to idle until the COOLANT TEMP reaches 75°C (167°F) or more.
6. Read the MAF with the engine in an idling condition and at an engine speed of 2,500 RPM.
  Standard:
  
  MAF while engine is idling:
  
  Between 3.2 g/s and 4.7 g/s (shift position: N, A/C: OFF).
  
  MAF at engine speed of 2,500 RPM:
  
  Between 13.1 g/s and 18.9 g/s (shift position: N, A/C: OFF).
NG: REPLACE MASS AIR FLOW METER (See REMOVAL )

OK: CHECK FOR INTERMITTENT PROBLEMS