Code No. P0558: Brake Booster Pressure Sensor Circuit High Input

OPERATION

A power voltage of 5 V is applied to the brake booster pressure sensor power terminal from the engine-ECU connector terminal BPS5 and earthed to the engine-ECU connector terminal BPES from the brake booster pressure sensor connector terminal.
The sensor signal is inputted to the engine-ECU connector terminal BBPS from the brake booster pressure sensor output terminal.

FUNCTION

The brake booster pressure sensor detects a change in brake booster negative pressure and inputs the signal to the engine-ECU.

TROUBLE JUDGMENT

Check Conditions

After 2 seconds since the ignition switch is turned ON or since the completion of engine start.
Battery positive voltage is more than 10 V and is less than 16.5 V.

Judgement Criterion

Senor output voltage is 4.8 V or more for two seconds (corresponding to 120 kPa or less of the brake booster pressure).

FAIL-SAFE AND BACKUP FUNCTION

Sets the variable valve lift control mode to negative pressure request mode (to set the valve lift higher than normal).

PROBABLE CAUSES

Failed brake booster pressure sensor
Open circuit or harness damage in brake booster pressure sensor circuit or loose connector contact
Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list

Refer to Data List Reference Table .

Item 171: Brake booster pressure sensor

Q. Is the check result normal?

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

	Go to Step 2.

STEP 2. Perform resistance measurement at brake booster pressure sensor connector.

Disconnect connector, and measure at harness side.
Resistance between terminal engine-ECU BPES line and body earth.

OK: Continuity (2 Ω or less)

Q. Is the check result normal?

	Go to Step 5.

	Go to Step 3.

STEP 3. Check harness between brake booster pressure sensor connector terminal and engine-ECU connector terminal BPES.

Check earthing line for open circuit and damage.

Q. Is the check result normal?

	Go to Step 4.

	Repair or replace the connector, or repair the damaged harness wire.

STEP 4. M.U.T.-III data list

Refer to Data List Reference Table .

Item 171: Brake booster pressure sensor

Q. Is the check result normal?

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

	Replace the engine-ECU.

STEP 5. M.U.T.-III data list

Refer to Data List Reference Table .

Item 171: Brake booster pressure sensor

Q. Is the check result normal?

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

	Go to Step 6.

STEP 6. Replace the brake booster pressure sensor

After replacing the brake booster pressure sensor, reconfirm whether the diagnosis code is set.

Q. Is the diagnosis code set?

	Replace the engine-ECU.

	Check end.