Toyota Corolla Cross: External BBC Circuit (P33B300)

DESCRIPTION

When the engine is started (high electrical load) from engine stopped by the stop and start control, the external backup boost converter (eco run vehicle converter assembly) supplements auxiliary battery voltage in order to prevent the function from being disabled due to decrease in power source voltage supplied to the audio and visual system.

After receiving a request from the engine stop and start ECU, the external backup boost converter (eco run vehicle converter assembly) helps maintain the power source voltage if the auxiliary battery voltage drops due to the high electrical load when the engine is restarted by stop and start control. The DON2 terminal of the external backup boost converter (eco run vehicle converter assembly) receives power supply voltage supplement requests from the engine stop and start ECU and switches from idle mode to supplement mode.

When the engine is started by the stop and start control, if the external backup boost converter (eco run vehicle converter assembly) does not maintain the specified voltage, an error is sent to the engine stop and start ECU. Then, the engine stop and start ECU stores DTC P33B300.

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 (51°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.

(a) Clear the DTCs.

(b) Start the engine and warm it up.

(c) Drive the vehicle at 7 km/h (4 mph) or more.

CAUTION:

When performing Confirmation Driving Pattern, obey all speed limits and traffic laws.

(d) Depress the brake pedal and stop the vehicle.

(e) Keep the engine stopped by stop and start control for 1 second or more. (Keep the shift lever in D.)

(f) Release the brake pedal with the shift lever in D to start the engine.

HINT:

If the engine cranks slowly when the engine is restarted, it can be determined that the auxiliary battery voltage is low.

(g) Check that DTCs are not output.

STOP AND START SYSTEM OPERATION CHECK

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WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

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

HINT:

• Using the GTS, read the freeze frame data before troubleshooting. System condition information is recorded as freeze frame data the moment a DTC is stored. This information can be useful when troubleshooting.

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• For wire harness and connector inspection procedures and precautions, refer to " "
• DTCs for the stop and start system are not cleared even if the malfunction has been repaired. After repairing the malfunction, be sure to clear the DTCs.

PROCEDURE

NOTICE:

Clearing the DTC will also clear the freeze frame data, so before clearing be sure to record the freeze frame data.

(a) Following the display on the GTS, check the freeze frame data and read "State of External BBC" in the freeze frame data when P33B300 was output.

A

REPLACE EXTERNAL BACKUP BOOST CONVERTER (ECO RUN VEHICLE CONVERTER ASSEMBLY)

B

REPLACE EXTERNAL BACKUP BOOST CONVERTER (ECO RUN VEHICLE CONVERTER ASSEMBLY)

D

GO TO STEP 4

C

(a) Check if the connector of the A166 external backup boost converter (eco run vehicle converter assembly) is connected securely.

OK:

The connector is securely connected.

NG

CONNECT CONNECTOR CORRECTLY

OK

(a) Disconnect the A166 external backup boost converter (eco run vehicle converter assembly) connector.

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

(a) Disconnect the A169 engine stop and start ECU connector.

(b) Disconnect the A166 external backup boost converter (eco run vehicle converter assembly) connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

(a) Disconnect the A166 external backup boost converter (eco run vehicle converter assembly) connector.

(b) Remove the PA BBC fuse from the No. 1 engine room relay block.

(c) Remove the ECU-ACC fuse from the power distribution box assembly.

(d) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

OK

REPLACE EXTERNAL BACKUP BOOST CONVERTER (ECO RUN VEHICLE CONVERTER ASSEMBLY)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

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