Toyota Corolla Cross: Internal Control Module Random Access Memory (RAM) Error Data Memory Failure (P060444)

MONITOR DESCRIPTION

The engine stop and start ECU continuously monitors its internal memory status. This self-check ensures that the engine stop and start ECU is functioning properly. The engine stop and start ECU memory status is diagnosed by internal mirroring of the main CPU and sub CPU to detect Random Access Memory (RAM) errors. If outputs from these CPUs are different and deviate from the standard, the engine stop and start ECU will illuminate the MIL and store this DTC.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

CONFIRMATION DRIVING PATTERN

CONFIRMATION AFTER TROUBLESHOOTING

HINT:

• If the cable is disconnected from the auxiliary battery terminal, stop and start control is prohibited until refresh charge is completed.

  In this case, let the vehicle idle to complete the refresh charge. The refresh charge is complete when the Data List item "Status of Battery Charge Control" changes from "Refresh Charge Mode". (Usually, by idling the engine for 5 to 60 minutes with the auxiliary battery fluid temperature at 11°C (52°F) or higher, the refresh charge will be completed.)

• If the GTS is not available and the Data List item "Status of Battery Charge Control" cannot be checked, charge the auxiliary battery by idling the engine for approximately 5 to 60 minutes or driving the vehicle, and then drive the vehicle and check that stop and start control operates.

  If the engine is started with the hood open, the system determines that a jump start has occurred. Therefore, make sure that the hood is closed before starting the engine and driving the vehicle.

• After the refresh charge completes, turn the ignition switch off, wait for at least 30 seconds, and then start the engine again. If the vehicle enters refresh charge mode again while the engine is idling, the initial refresh charge did not properly complete, so wait for the refresh charge to complete.
• Allow the engine to idle for 3 minutes after it is warmed up and check that the engine idle speed is within 50 rpm of the target idle speed.
• When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.

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• When clearing the permanent DTCs, do not disconnect the cable from the auxiliary battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.

(a) Clear the DTCs.

(b) Disconnect the cable from the negative (-) auxiliary battery terminal and wait for 1 minute.

(c) Connect the cable to the negative (-) auxiliary battery terminal.

(d) Turn the ignition switch to ON.

(e) Wait 16 seconds or more.

(f) Enter the following menus.

(g) 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.

STOP AND START SYSTEM OPERATION CHECK

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CAUTION / NOTICE / HINT

NOTICE:

• After turning ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

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PROCEDURE

(a) Clear the DTCs.

(b) Turn the ignition switch off.

NEXT

(a) Disconnect the cable from the negative (-) auxiliary battery terminal and wait for 1 minute.

(b) Connect the cable to the negative (-) auxiliary battery terminal.

(c) Turn the ignition switch to ON.

(d) Wait 16 seconds or more.

(e) Read the DTCs.

A

USE SIMULATION METHOD TO CHECK

B

REPLACE ENGINE STOP AND START ECU

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