2ZR-FAE (ENGINE CONTROL): SFI SYSTEM: P10A0,P1055; VALVEMATIC Angle Difference(CSS); 2020 - 2023 MY Corolla [03/2019

The VALVEMATIC system is able to continuously change the valve lift amount and valve timing. The VALVEMATIC system cooperates with the VVT-i to adjust the valve lift amount and valve timing optimally according to driving conditions. The ECM calculates the target intake air amount based on the amount the accelerator pedal is depressed and the engine speed to determine the valve lift amount (duration), valve timing and throttle valve opening angle. The continuously variable valve lift controller assembly operates the actuator to adjust the duration to the duration requested by the ECM via CAN communication. The actual operating conditions are monitored by the sensors in the continuously variable valve lift controller assembly, which sends the actual duration value to the ECM. The continuously variable valve lift controller assembly consists of the EDU, actuator, differential roller gear, angle sensor and position sensor.

Perform the following procedures to confirm that the VALVEMATIC system is operating normally.

Connect the Techstream to the DLC3.
Start the engine.
Turn the Techstream on.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the VALVEMATIC(ENG ON) / Data List / VALVEMATIC Current Angle and VALVEMATIC Target Angle.
Click here

NOTICE:

Make sure the following conditions are met when performing the Active Test.
- The engine is idling.
- The engine coolant temperature is 40°C (104°F) or higher.
- The vehicle is stationary.
- The shift lever is in P or N (neutral).
The "VALVEMATIC Current Angle" follows the "VALVEMATIC Target Angle".

Perform a simulation test by referring to the engine coolant temperature and intake air temperature recorded in the Freeze Frame Data.

When the Active Test results are abnormal, remove the continuously variable valve lift controller assembly from the camshaft housing sub-assembly and perform the "Activate the VALVEMATIC(ENG OFF)" Active Test with the continuously variable valve lift controller assembly removed to determine whether the problem is with the continuously variable valve lift controller assembly or camshaft housing sub-assembly.

MONITOR DESCRIPTION

The ECM monitors the continuously variable valve lift controller assembly and detects malfunctions. If the actual duration differs from the requested duration by 14.5°CA or higher, the ECM illuminates the MIL and stores a DTC. DTC P10A0 is usually only stored if a malfunction is detected during cold engine start. DTC P1055 is stored if a malfunction is detected in any other situation.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

P10A0

P1055

TYPICAL MALFUNCTION THRESHOLDS

CONFIRMATION DRIVING PATTERN

P10A0

Connect the Techstream to the DLC3.
Start the engine and warm it up (until the engine coolant temperature 75°C (167°F) or higher).
Turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON.
Turn the Techstream on.
Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
Check that the "Coolant Temp" is between -10 to 60°C (14 to 140°F).
Start the engine.
Enter the following menus: Powertrain / Engine and ECT / Data List / Accelerator Idle Position and VALVEMATIC Current Angle.
Check that the "Accelerator Idle Position" is ON and "VALVEMATIC Current Angle" is 150 deg(CA).
Idle the engine for 20 seconds.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Read the pending DTCs.
HINT:
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P10A0.

Check the DTC judgment result.

Techstream Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

HINT:

If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.

If the judgment result is INCOMPLETE or N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs.
Click here
HINT:
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

P1055

Connect the Techstream to the DLC3.
Start the engine and warm it up (until the engine coolant temperature 75°C (167°F) or higher).
Turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the ignition switch off and wait for at least 30 seconds.
Start the engine and idle it for 20 seconds.
Turn the Techstream on.
Clear the DTCs.
Turn the ignition switch off and wait for at least 30 seconds.
Start the engine and idle it for 20 seconds.
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON.
Turn the Techstream on.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Read the pending DTCs.
HINT:
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P1055.

Check the DTC judgment result.

Techstream Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

HINT:

If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.

If the judgment result is INCOMPLETE or N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs.
Click here
HINT:
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

CAUTION / NOTICE / HINT

When one of the following DTCs is output and the MIL is illuminated, actuator position learning is performed during the next trip. After the system returns to normal, actuator position learning is performed during the next trip and the MIL remains illuminated until learning is complete.

HINT:

Do not disconnect the cable from the negative (-) battery terminal when the power supply of the continuously variable valve lift controller assembly is energized.
Because the VALVEMATIC system memorizes settings when the ignition switch is turned off, make sure to wait at least 1 minute after turning the ignition switch off before disconnecting the cable from the negative (-) battery terminal.
If the cable is disconnected from the negative (-) battery terminal when the power supply is energized or within 1 minute after turning the ignition switch off, DTC P10A0 or P1055 may be stored.
After performing repairs, perform the following procedures and check that DTCs are not output again.
After using the Techstream to perform minimum valve lift learning, keep the engine idling for 30 seconds to complete learning. Otherwise, the VALVEMATIC system may not operate normally, causing poor acceleration, etc.
Read Freeze Frame Data using the Techstream. The ECM 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 moving or stationary, 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.

PROCEDURE

Powertrain > Engine and ECT > Trouble Codes

HINT:

If an engine coolant temperature sensor malfunction DTC or intake air temperature sensor malfunction DTC is output at the same time as DTC P1055 or P10A0, check the corresponding temperature sensor first.
After repairing the temperature sensor, clear the DTCs, perform a simulation test and check that the temperature sensor DTC is not output.
When the temperature sensor DTC does not recur but DTC P1055 or P10A0 is output again, perform troubleshooting from the next step. If a DTC is not output, troubleshooting is complete.

(d) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

Powertrain > Engine and ECT > Trouble Codes

(a) Remove the continuously variable valve lift controller assembly from the camshaft housing sub-assembly.

(f) Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the VALVEMATIC(ENG OFF) / Data List / VALVEMATIC Current Angle.

Powertrain > Engine and ECT > Active Test

(g) When the continuously variable valve lift controller assembly is operated using the Techstream, check whether the shaft moves.