Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001K0LC
Model Year Start: 2020 Model: Avalon HV Prod Date Range: [08/2019 -           ]
Title: A25A-FXS (ENGINE MECHANICAL): ENGINE: ON-VEHICLE INSPECTION; 2020 - 2022 MY Avalon HV [08/2019 -        ]

ON-VEHICLE INSPECTION

CAUTION / NOTICE / HINT

CAUTION:

To prevent injury due to contact with an operating cooling fan, keep your hands and clothing away from the cooling fans when working in the engine compartment with the engine running or the power switch on (IG).

PROCEDURE

1. INSPECT ENGINE COOLANT (for Engine)

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (COOLING): COOLING SYSTEM: ON-VEHICLE INSPECTION

2. INSPECT ENGINE OIL

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (LUBRICATION): LUBRICATION SYSTEM: ON-VEHICLE INSPECTION

3. INSPECT AUXILIARY BATTERY

Click here 2019 - 2021 MY Avalon HV [04/2018 - 08/2021]; A25A-FXS (BATTERY / CHARGING): CHARGING SYSTEM: ON-VEHICLE INSPECTION 2022 MY Avalon HV [08/2021 -        ]; A25A-FXS (BATTERY / CHARGING): CHARGING SYSTEM: ON-VEHICLE INSPECTION

4. INSPECT SPARK PLUG

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): IGNITION SYSTEM: ON-VEHICLE INSPECTION

5. INSPECT AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY

(a) Remove the air cleaner filter element sub-assembly.

(b) Visually check that the air cleaner filter element sub-assembly is not damaged or excessively oily.

HINT:

  • If there is any dirt or clogs in the air cleaner filter element sub-assembly, clean it with compressed air.
  • If any dirt or clogs remain even after cleaning the air cleaner filter element sub-assembly with compressed air, replace it.

(c) Install the air cleaner filter element sub-assembly.

6. INSPECT VALVE LASH ADJUSTER ASSEMBLY NOISE

(a) Put the engine in inspection mode.

Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; INTRODUCTION: REPAIR INSTRUCTION: INSPECTION MODE PROCEDURE

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

(c) 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 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE MECHANICAL): ENGINE UNIT: INSPECTION+

7. 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 park.

(a) Put the engine in inspection mode.

Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; INTRODUCTION: REPAIR INSTRUCTION: INSPECTION MODE PROCEDURE

(b) Warm up and stop the engine.

(c) Connect the Techstream to the DLC3.

(d) Put the engine in inspection mode.

Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; INTRODUCTION: REPAIR INSTRUCTION: INSPECTION MODE PROCEDURE

(e) Enter the following menus: Powertrain / Engine / Data List / Ignition Timing Cylinder #1.

Powertrain > Engine > Data List

Tester Display

Ignition Timing Cylinder #1

Standard Ignition Timing:

-2 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 / Active Test / Activate the TC Terminal / ON.

Powertrain > Engine > Active Test

Active Test Display

Activate the TC Terminal

Data List Display

Ignition Timing Cylinder #1

(h) Monitor Ignition Timing Cylinder #1 of the Data List.

Standard Ignition Timing:

8 to 12° BTDC at idle

8. INSPECT ENGINE IDLE SPEED

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 park.

(a) Put the engine in inspection mode.

Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; INTRODUCTION: REPAIR INSTRUCTION: INSPECTION MODE PROCEDURE

(b) Warm up and stop the engine.

(c) Connect the Techstream to the DLC3.

(d) Put the engine in inspection mode.

Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; INTRODUCTION: REPAIR INSTRUCTION: INSPECTION MODE PROCEDURE

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

Powertrain > Engine > Data List

Tester Display

Engine Speed

(f) Read the value displayed on the Techstream.

Standard Idle Speed:

1050 to 1150 rpm

9. INSPECT COMPRESSION

NOTICE:

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

(a) Put the engine in inspection mode.

Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; INTRODUCTION: REPAIR INSTRUCTION: INSPECTION MODE PROCEDURE

(b) Warm up and stop the engine.

(c) Check for DTCs.

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR

(d) Remove the front wheel opening extension pad RH.

Click here 2019 - 2021 MY Avalon HV [04/2018 - 08/2021]; A25A-FXS (ENGINE MECHANICAL): ENGINE ASSEMBLY: REMOVAL+ 2022 MY Avalon HV [08/2021 -        ]; A25A-FXS (ENGINE MECHANICAL): ENGINE ASSEMBLY: REMOVAL+

(e) Remove the front wheel opening extension pad LH.

Click here 2019 - 2021 MY Avalon HV [04/2018 - 08/2021]; A25A-FXS (ENGINE MECHANICAL): ENGINE ASSEMBLY: REMOVAL+ 2022 MY Avalon HV [08/2021 -        ]; A25A-FXS (ENGINE MECHANICAL): ENGINE ASSEMBLY: REMOVAL+

(f) Remove the No. 1 engine under cover.

Click here 2019 - 2021 MY Avalon HV [04/2018 - 08/2021]; A25A-FXS (ENGINE MECHANICAL): ENGINE ASSEMBLY: REMOVAL+ 2022 MY Avalon HV [08/2021 -        ]; A25A-FXS (ENGINE MECHANICAL): ENGINE ASSEMBLY: REMOVAL+

(g) Remove the No. 2 engine under cover assembly.

Click here 2019 - 2021 MY Avalon HV [04/2018 - 08/2021]; A25A-FXS (ENGINE MECHANICAL): ENGINE ASSEMBLY: REMOVAL+ 2022 MY Avalon HV [08/2021 -        ]; A25A-FXS (ENGINE MECHANICAL): ENGINE ASSEMBLY: REMOVAL+

(h) Remove the 4 spark plugs.

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; MAINTENANCE: A25A-FXS SPARK PLUG: REMOVAL

NOTICE:

DTCs will be stored if the inspection is performed with the ignition coil assembly connectors disconnected. Make sure that the ignition coil assembly connectors are connected during the inspection.

(i) Disconnect the fuel injector connector (for Port Injection).

(j) Disengage the claw and raise the lock lever to disconnect the fuel injector connector (for Direct Injection) as shown in the illustration.

*a

Lock Lever

(k) Check the cylinder compression pressure.

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

(2) Connect the Techstream to the DLC3.

(3) Turn the power switch on (IG).

(4) Turn the Techstream on.

NOTICE:

Check the HV battery voltage in the Data List to ensure that the battery is fully charged.

(5) Enter the following menus: Powertrain / Hybrid Control / Active Test / Compression Test / ON.

Powertrain > Hybrid Control > Active Test

Tester Display

Compression Test

(6) Depress and hold the brake pedal, and turn the power switch on (READY). Then check the compression pressure.

Standard Compression Pressure:

870 kPa (8.9 kgf/cm2, 126 psi)

Minimum Compression Pressure:

700 kPa (7.1 kgf/cm2, 102 psi)

Pressure Difference between Each Cylinder:

200 kPa (2.0 kgf/cm2, 29 psi) or less

NOTICE:

  • Noise may be emitted from the hybrid vehicle transaxle assembly. However, this is not a malfunction.
  • Inspect all cylinders in the same way.
  • Measure the compression pressure as quickly as possible.

(7) 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 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.

(l) Connect the fuel injector connector (for Direct Injection) and push down the lock lever to engage the claw as shown in the illustration.

*a

Lock Lever

(m) Connect the fuel injector connector (for Port Injection).

(n) Install the 4 spark plugs.

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; MAINTENANCE: A25A-FXS SPARK PLUG: INSTALLATION

(o) Install the No. 2 engine under cover assembly.

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE MECHANICAL): ENGINE ASSEMBLY: INSTALLATION+

(p) Install the No. 1 engine under cover.

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE MECHANICAL): ENGINE ASSEMBLY: INSTALLATION+

(q) Install the front wheel opening extension pad LH.

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE MECHANICAL): ENGINE ASSEMBLY: INSTALLATION+

(r) Install the front wheel opening extension pad RH.

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE MECHANICAL): ENGINE ASSEMBLY: INSTALLATION+

(s) Clear the DTCs.

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR

NOTICE:

After performing the inspection, clear the DTCs and confirm that DTCs are not stored again or that the normal system code is output if using a check wire.

10. INSPECT CO/HC

HINT:

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

(a) Put the engine in inspection mode.

Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; INTRODUCTION: REPAIR INSTRUCTION: INSPECTION MODE PROCEDURE

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

(c) Insert a CO/HC meter testing probe at least 40 cm (1.31 ft.) into the tailpipe during idle.

(d) Immediately check the CO/HC concentration at idle and then at an engine speed of 2500 rpm.

HINT:

When performing a 2 mode test (with the engine idling/running at 2500 rpm), 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 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR

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

CO

HC

Problem

Cause

Normal

High

Rough idle
  1. Faulty ignition:
    • Incorrect valve timing
    • Fouled, shorted or improperly gapped spark plugs
  2. Incorrect valve clearance (valve lash adjuster assembly)
  3. Leaks in intake or exhaust valves
  4. Leaks in cylinders
  5. Faulty EGR

Low

High

Rough idle (Fluctuating HC reading)
  1. Vacuum leaks:
    • PCV hoses
    • Intake manifold
    • Throttle body with motor assembly
  2. Lean mixture causing misfire
  3. Faulty EGR

High

High

Rough idle (Black smoke from exhaust)
  1. Restricted air cleaner filter element sub-assembly
  2. Plugged PCV valve
  3. Faulty SFI systems:
    • Fuel pressure regulator assembly
    • Engine coolant temperature sensor
    • Mass air flow meter sub-assembly
    • ECM
    • Fuel injector assemblies
    • Throttle position sensor (built into throttle body with motor assembly)
  4. Faulty EGR