2ZR-FAE (ENGINE MECHANICAL): ENGINE: ON-VEHICLE INSPECTION; 2020 - 2023 MY Corolla [01/2019

Last Modified: 07-31-2024	6.11:8.1.0	Doc ID: RM100000001G44Z
Model Year Start: 2020	Model: Corolla	Prod Date Range: [01/2019 - 11/2022]
Title: 2ZR-FAE (ENGINE MECHANICAL): ENGINE: ON-VEHICLE INSPECTION; 2020 - 2023 MY Corolla [01/2019 - 11/2022]

ON-VEHICLE INSPECTION

CAUTION / NOTICE / HINT

CAUTION:

When working near the engine room while the engine has started or the ignition switch is ON, do not touch the rotating components such as the V-ribbed belt or cooling fan.
Touching the rotating components such as the V-ribbed belt or cooling fan. could result in your hand or clothing getting caught and pulled in.

PROCEDURE

1. INSPECT ENGINE COOLANT

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2. INSPECT ENGINE OIL

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3. INSPECT BATTERY

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4. INSPECT AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY

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5. INSPECT SPARK PLUG

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6. INSPECT V-RIBBED BELT

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7. INSPECT VALVE AND ADJUSTER NOISE

(a) Rev up the engine several times. Check that the engine does not emit unusual noises.

(b) If unusual noises occur, warm up the engine and idle it for 30 minutes or more, then perform the inspection.

HINT:

If any defects or problems are found during the inspection, perform valve lash adjuster assembly inspection.

Click here

8. INSPECT IGNITION TIMING

NOTICE:

Check the ignition timing with the cooling fan off.
Turn off all electrical systems and the A/C.
When checking the ignition timing, the transaxle should be in neutral or park.

(a) Warm up and stop the engine.

(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

(e) Enter the following menus: Powertrain / Engine and ECT / Data List / IGN Advance.

Powertrain > Engine and ECT > Data List

Tester Display
IGN Advance

Standard Ignition Timing:

0 to 14° BTDC at idle

(f) Check that the ignition timing advances immediately when the engine speed is increased.

(g) Enter the following menus: Powertrain / Engine and ECT / Active Test / Connect the TC and TE1 / ON.

Powertrain > Engine and ECT > Active Test

Active Test Display
Connect the TC and TE1

Data List Display
IGN Advance

(h) Monitor IGN Advance of the Data List.

Standard Ignition Timing:

8 to 12° BTDC at idle

NOTICE:

When checking the ignition timing, the transaxle should be in neutral or park.

9. INSPECT ENGINE IDLE SPEED

NOTICE:

Turn off all electrical systems and the A/C.
Inspect the engine idle speed with the cooling fan off.
When checking the engine idle speed, the transaxle should be in neutral or park.

(a) Warm up and stop the engine.

(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

(e) Enter the following menus: Powertrain / Engine and ECT / Data List / Engine Speed.

Powertrain > Engine and ECT > Data List

Tester Display
Engine Speed

(f) Read the value displayed on the Techstream.

Standard Idle Speed:

for CVT

700 to 800 rpm

for Manual Transaxle

600 to 700 rpm

10. INSPECT COMPRESSION

NOTICE:

Keep the spark plug holes free of foreign matter when measuring the compression pressure.

(a) Warm up and stop the engine.

(b) Check for DTCs.

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(d) Disconnect the 4 fuel injector connectors.

NOTICE:

Disable fuel injection in order to prevent catalyst damage due to unburned gasoline.

(e) Remove the air cleaner cap with air cleaner hose.

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(f) w/ Stud Bolt:

(1) Remove the 2 bolts, 2 nuts and separate the throttle body assembly from the intake manifold.

*A	w/ Stud Bolt
*B	w/o Stud Bolt

(g) w/o Stud Bolt:

(1) Remove the 4 bolts and separate the throttle body assembly from the intake manifold.

(h) Check the cylinder compression pressure.

(1) Insert a compression gauge into the spark plug hole.

(2) While cranking the engine, measure the compression pressure.

Standard Compression Pressure:

1373 kPa (14.0 kgf/cm², 199 psi)

Minimum Compression Pressure:

980 kPa (10.0 kgf/cm², 142 psi)

Pressure Difference between Each Cylinder:

100 kPa (1.0 kgf/cm², 15 psi)

NOTICE:

Use a fully-charged battery so that the engine speed can be increased to 250 rpm or more.
Inspect the other cylinders in the same way.
Measure the compression pressure as quickly as possible.

(3) If the cylinder compression pressure is low, pour a small amount of engine oil into the cylinder through the spark plug hole and inspect it again.

HINT:

If adding engine oil increases the compression pressure, the piston rings and/or cylinder bore may be worn or damaged.
If the compression pressure stays low, a valve may be stuck or seated improperly, or there may be leaks in the cylinder head gasket.

(i) w/ Stud Bolt:

(1) Install a new throttle body gasket and the throttle body assembly to the intake manifold with the 2 bolts and 2 nuts.

Torque:

10 N·m {102 kgf·cm, 7 ft·lbf}

NOTICE:

If the throttle body assembly has been struck or dropped, replace it.

(j) w/o Stud Bolt:

(1) Install a new throttle body gasket and the throttle body assembly to the intake manifold with the 4 bolts.

Torque:

10 N·m {102 kgf·cm, 7 ft·lbf}

NOTICE:

If the throttle body assembly has been struck or dropped, replace it.

(k) Install the air cleaner cap with air cleaner hose.

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(l) Connect the 4 fuel injector connectors.

(m) Install the 4 spark plugs.

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(n) Clear the DTCs.

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NOTICE:

After the inspection, clear the DTCs, check for DTCs again and make sure the normal system code is output.

11. INSPECT CO/HC

HINT:

This check determines whether or not the idle CO/HC complies with regulations.

(a) Start the engine.

(b) Keep the engine at 2500 rpm for approximately 180 seconds.

(d) Immediately check the CO/HC concentration during idle and when the engine is running at 2500 rpm.

HINT:

When doing a 2 mode (with the engine idling/running at 2500 rpm) test, the measurement procedures are determined by applicable local regulations.

If the CO/HC concentration does not comply with the regulations, perform troubleshooting in the order given below.

(1) Check for DTCs.

Click here

(2) See the following table for possible causes, then inspect the applicable parts and repair them if necessary.

CO	HC	Problem	Possible Cause
Normal	High	Rough idle	Faulty ignition: Incorrect timing Fouled, shorted or improperly gapped plugs Incorrect valve clearance Leaks in intake or exhaust valves Leaks in cylinders
Low	High	Rough idle (Fluctuating HC reading)	Vacuum leaks: Ventilation hose Intake manifold Throttle body assembly Brake booster line Lean mixture causing misfire
High	High	Rough idle (Black smoke from exhaust)	Restricted air cleaner filter element sub-assembly Plugged PCV valve Faulty EFI systems: Pressure regulator Engine coolant temperature sensor Mass air flow meter sub-assembly ECM Injector assemblies Throttle body assembly