2ZR-FAE (ENGINE CONTROL): SFI SYSTEM: U011B; Lost Communication with Rocker Arm Control Module "A"; 2020 - 2023 MY Corolla [03/2019

The ECM and continuously variable valve lift controller assembly communicate via the CAN communication system.

MONITOR DESCRIPTION

When between the ECM and the continuously variable valve lift controller assembly is a malfunction in the CAN communication, this DTC is stored and the MIL is illuminated.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

CONFIRMATION DRIVING PATTERN

Connect the Techstream to the DLC3.
Start the engine and warm it up.
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: U011B.

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.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

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.

Actuator position learning is performed when these DTCs are output.
P1049, P104A, P1055, P2646, P2647, P2648, P2649, P264A, U011B

Inspect the fuses for circuits related to this system before performing the following procedure.

HINT:

When there is no power (+B) supplied to the continuously variable valve lift controller assembly, DTC U011B is stored. Also, if the SDWN circuit is open, power supply is stopped and DTC U011B is stored.
After performing repairs, perform the following procedure 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

(a) Disconnect the continuously variable valve lift controller assembly connector.

Perform "Inspection After Repair" after replacing the continuously variable valve lift controller assembly.

Powertrain > Engine and ECT > Clear DTCs

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