Toyota Corolla Cross: Brake Booster Pressure Sensor(running) (P055500,P05552A)

DESCRIPTION

The engine stop and start ECU determines changes in the brake booster assembly pressure based on the voltage signal received from the vacuum sensor assembly in the brake booster assembly.

If the output value of the vacuum sensor assembly remains the same even though the brake booster assembly pressure changes when the brake pedal is operated or the vehicle is being driven, the engine stop and start ECU judges that the sensor is stuck.

When sticking of the sensor is detected, the engine stop and start ECU stores DTC P055500 or P05552A and blinks the stop and start cancel indicator.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Warning Indicate	Note
P055500	Brake Booster Pressure Sensor(running)	The change in vacuum while stopping the vehicle 30 times from a speed of 30 km/h (19 mph) or more was 0.3 kPa (2 mmHg, 0.09 in.Hg) or less (1 trip detection logic).	Vacuum sensor assembly Brake booster assembly Vacuum hose (brake booster hose) Engine stop and start ECU	Does not come on	Blinks	SAE Code: P0556
P05552A	Brake Booster Pressure Sensor Signal Stuck In Range	The change in vacuum is 0.3 kPa (2 mmHg, 0.09 in.Hg) or less more than 3 times when the brake pedal is firmly depressed to stop the vehicle (deceleration of 0.15 G or more for 1 second or more) (1 trip detection logic).	Vacuum sensor assembly Brake booster assembly Vacuum hose (brake booster hose) Engine stop and start ECU	Does not come on	Blinks	SAE Code: P0556

CONFIRMATION DRIVING PATTERN

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.

CONFIRMATION AFTER TROUBLESHOOTING

(a) Clear the DTCs.

Powertrain > Stop and Start > Clear DTCs

(b) Start the engine and warm it up.

(c) Enter the following menus.

Powertrain > Stop and Start > Data List

Tester Display
Brake Boost Pressure

(d) Drive the vehicle at 30 km/h (19 mph) or more and stop the vehicle. Repeat this driving pattern 30 times to allow the brake booster vacuum to change.

CAUTION:

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

(e) Stop the vehicle.

(f) Check that DTCs are not output.

Powertrain > Stop and Start > Trouble Codes

STOP AND START SYSTEM OPERATION CHECK

Click here

CAUTION / NOTICE / HINT

NOTICE:

• Before replacing the engine stop and start ECU, read the number of starter operations and write it into a new engine stop and start ECU.

  Click here

• After replacing the engine stop and start ECU, perform learning of the external backup boost converter (eco run vehicle converter assembly).

  Click here

• After replacing the engine stop and start ECU or air conditioning amplifier assembly, reset and perform learning of the air conditioning information in the engine stop and start ECU.

  Click here

• When the engine stop and start ECU or oil pump with motor assembly is replaced, check the oil pump with motor assembly.

  Click here

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.

  Click here

• 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

1.	CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P055500 OR P05552A)

(a) Read the DTCs.

Powertrain > Stop and Start > Trouble Codes

Result	Proceed to
DTC P055500 or P05552A is output	A
DTC P055500 or P05552A and other DTCs output	B

HINT:

If any DTCs other than P055500 or P05552A are output, troubleshoot those DTCs first.

B

GO TO DIAGNOSTIC TROUBLE CODE CHART

A

2.	READ VALUE USING GTS (BRAKE BOOST PRESSURE)

(a) Start the engine and warm it up.

(b) Turn the ignition switch off. (*1)

(c) Turn the ignition switch to ON. (*2)

HINT:

Do not start the engine.

(d) Enter the following menus. (*3)

Powertrain > Stop and Start > Data List

Tester Display
Brake Boost Pressure

(e) Depress the brake pedal 5 times and read the changes in the following pressure value.

OK:

GTS Display	Condition	Normal Condition
Brake Boost Pressure	Ignition switch ON Brake pedal depressed 5 times	Changes by 20 kPa (150 mmHg, 5.91 in. Hg) or higher

NOTICE:

Because it is hard to cause variation in the internal pressure before and after depressing the brake pedal if the brake booster internal pressure is high before depressing the brake pedal, do not operate the brake pedal as much as possible between operations (*1) and (*3).

OK

USE SIMULATION METHOD TO CHECK

NG

3.	INSPECT VACUUM HOSE (BRAKE BOOSTER HOSE)

(a) Visually check the vacuum hose (brake booster hose) for cracks or clogging.

HINT:

If the braking force is abnormal, inspect the brake booster assembly.

OK:

No cracks or clogging in the vacuum hose (brake booster hose).

NG

REPLACE VACUUM HOSE

OK

4.	REPLACE VACUUM SENSOR ASSEMBLY

Click here

NEXT

5.

CLEAR DTC

(a) Clear the DTC.

Powertrain > Stop and Start > Clear DTCs

NEXT

6.	CHECK DTC OUTPUT

(a) Start the engine and warm it up.

(b) Enter the following menus.

Powertrain > Stop and Start > Data List

Tester Display
Brake Boost Pressure

(c) Drive the vehicle at 30 km/h (19 mph) or more and stop the vehicle. Repeat this driving pattern 30 times to allow the brake booster vacuum to change.

CAUTION:

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

(d) Stop the vehicle.

(e) Check that no DTCs are output.

Powertrain > Stop and Start > Trouble Codes

Result	Proceed to
DTCs are not output	A
DTC P055500 or P05552A is output	B

A

END

B

REPLACE ENGINE STOP AND START ECU

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