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 | Warning Indicate | Memory | 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). |
| Blinks | DTC stored | 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). |
| Blinks | DTC stored | SAE Code: P0556 |
CONFIRMATION DRIVING PATTERN
HINT:
In this case, let the vehicle idle to complete the refresh charge. The refresh charge is complete when the Data List item Status of Auxiliary Battery Charge Control changes from "Refresh Charge Mode". (Usually, 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 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.
CONFIRMATION AFTER TROUBLESHOOTING
(a) Clear the DTCs.
Powertrain > Stop and Start > Clear DTCs(b) Start the engine and warm it up.
Powertrain > Stop and Start > Data List Tester Display |
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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 DTCs are not output.
Powertrain > Stop and Start > Trouble CodesSTOP AND START SYSTEM OPERATION CHECK
Click here
CAUTION / NOTICE / HINT
NOTICE:
Click here
Click here
Click here
HINT:
Click here
Click here
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 |
|
2. | READ VALUE USING GTS (BRAKE BOOST PRESSURE) |
(a) Start the engine and warm it up.
(b) Turn the ignition switch off. (*1)
(c) Connect the GTS to the DLC3.
(d) Turn the ignition switch to ON. (*2)
HINT:
Do not start the engine.
(e) Turn the GTS on.
(f) Enter the following menus: Powertrain / Stop and Start / Data List / Brake Boost Pressure. (*3)
Powertrain > Stop and Start > Data List Tester Display |
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Brake Boost Pressure |
(g) Depress the brake pedal 5 times and read the changes in the following pressure value.
OK:
GTS Display | Condition | Normal Condition |
---|---|---|
Brake Boost Pressure |
| 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 |
|
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 |
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4. | REPLACE VACUUM SENSOR ASSEMBLY |
Click here
|
5. | CLEAR DTC |
(a) Clear the DTC.
Powertrain > Stop and Start > Clear DTCs
|
6. | CHECK DTC OUTPUT |
(a) Start the engine and warm it up.
Powertrain > Stop and Start > Data List Tester Display |
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Brake Boost Pressure |
(b) 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.
(c) Stop the vehicle.
(d) Check that no DTCs are output.
Powertrain > Stop and Start > Trouble Codes Result | Proceed to |
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DTCs are not output | A |
DTC P055500 or P05552A is output | B |
A | END |
B | REPLACE ENGINE STOP AND START ECU |
Automatic transaxle: Shift the selector lever to the P position and set the parking brake.
Press the push button start to turn off the engine. The ignition position is off.