Last Modified: 11-29-2007 1.6 G
Service Category: Engine/Hybrid System Section: Engine Control
Model Year: 2008 Model: Sequoia Doc ID: RM000002N0600JX
Title: 3UR-FE ENGINE CONTROL: IGNITION SYSTEM: ON-VEHICLE INSPECTION (2008 Sequoia)

ON-VEHICLE INSPECTION

1. PERFORM SPARK TEST

(a) Check for DTCs 3UR-FE ENGINE CONTROL: SFI SYSTEM: DIAGNOSTIC TROUBLE CODE CHART (2008 Sequoia) .

NOTICE:

If any DTC is present, perform troubleshooting procedures for that DTC.

(b) Check if sparks occur.

(1) Remove the ignition coils and spark plugs 3UR-FE ENGINE CONTROL: IGNITION COIL AND SPARK PLUG: REMOVAL (2008 Sequoia) .

(2) Install the spark plug to the ignition coil and connect the ignition coil connector.

(3) Disconnect the 8 injector connectors.


(4) Ground the spark plug.

(5) Visually check that sparks occur while the engine is being cranked.

NOTICE:

  • Be sure to ground the spark plug when checking.
  • If the ignition coil has been struck or dropped, replace it.
  • Do not crank the engine for more than 2 seconds.

(c) Perform the spark test according to the procedures below:

(1) Check that the wire harness side connector of the ignition coil with igniter is securely connected.

Result

Result

Proceed to

NG

Connect securely

OK

Go to next step

(2) Perform a spark test on each ignition coil with igniter.

  • If there is a cylinder where sparks do not occur, replace its ignition coil with the ignition coil of a cylinder where sparks occur normally.
  • Crank the engine and visually check that sparks occur at the cylinder with the normally operating ignition coil.

Result

Result

Proceed to

OK

Replace ignition coil with igniter

NG

Go to next step

(3) Check spark plug.

Result

Result

Proceed to

NG

Replace spark plug

OK

Go to next step

(4) Check the power supply to the ignition coil with igniter.

  • Turn the ignition switch to ON.
  • Check that there is battery voltage at the ignition coil positive (+) terminal.

Result

Result

Proceed to

NG

Check wiring between ignition switch and ignition coil with igniter

OK

Go to next step

(5) Check the VVT sensor for intake camshaft 3UR-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 Sequoia) .

(6) Check the VVT sensor for exhaust camshaft 3UR-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 Sequoia) .

(7) Check the camshaft position sensor 3UR-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 Sequoia) .

(8) Check the crankshaft position sensor 3UR-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 Sequoia) .

(9) Check the IGT signal circuit 3UR-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 Sequoia) .

(d) Connect the 8 injector connectors.

(e) Install the ignition coils and spark plugs 3UR-FE ENGINE CONTROL: IGNITION COIL AND SPARK PLUG: INSTALLATION (2008 Sequoia) .

2. INSPECT SPARK PLUG

NOTICE:

  • Do not use a wire brush for cleaning.
  • Do not attempt to adjust the electrode gap of a used spark plug.

(a) Check the electrode.


(1) Using a megohmmeter, measure the resistance.

Standard Resistance:

Tester Connection

Condition

Specified Condition

Spark plug (terminal part) - Body ground

Always

10 MΩ or higher

If the insulation resistance is below the specified range, replace the spark plug.

HINT:

If a megohmmeter is not available, perform the following simple inspection instead.

(b) Alternative inspection method:

(1) Quickly accelerate the engine to 4000 rpm 5 times.

(2) Remove the spark plug.


(3) Visually check the spark plug.

If the electrode is dry, the spark plug is functioning properly. If the electrode is damp, proceed to the next step.

(c) Check the spark plug for any damage to its threads and insulator.

If there is any damage, replace the spark plug.

Recommended Spark Plug

Manufacturer

Type

DENSO made

SK20HR11



HINT:

NOTICE:

If adjusting the gap of a new spark plug, bend only the base of the ground electrode. Do not touch the tip. Never attempt to adjust the gap of a used plug.



If the electrode has traces of wet carbon, allow it to dry and then clean it with a spark plug cleaner.

Standard air pressure:

588 kPa (6.0 kgf/cm2, 85 psi)

Standard duration:

20 seconds or less

HINT:

Only use the spark plug cleaner when the electrode is free of oil. If the electrode has traces of oil, use gasoline to clean off the oil before using the spark plug cleaner.