DTC P0555:00 [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5]


id0102h9950200

DTC P0555:00

Power brake unit vacuum sensor circuit problem

DETECTION CONDITION
•  The PCM monitors the power brake unit vacuum sensor signal voltage while the ignition switch is ON. If the PCM detects the power brake unit vacuum sensor voltage is below 0.15 V or above 4.8 V for 5 s, the PCM determines that the power brake unit vacuum sensor circuit has problem.
Diagnostic support note
•  This is a continuous monitor (other).
•  The check engine light does not illuminate.
•  FREEZE FRAME DATA (Mode 2)/Snapshot data is not available.
•  DTC is stored in the PCM memory.
FAIL-SAFE FUNCTION
•  Flashes the i-stop warning light (amber) and inhibits engine-stop by operating the i-stop function.
POSSIBLE CAUSE
•  Power brake unit vacuum sensor connector or terminals malfunction
•  Short to ground in wiring harness between the following terminals:
―  Power brake unit vacuum sensor terminal A—PCM terminal 2BG
―  Power brake unit vacuum sensor terminal B—PCM terminal 2Q
•  PCM connector or terminals malfunction
•  Short to power supply in wiring harness between power brake unit vacuum sensor terminal B and PCM terminal 2Q
•  Power brake unit vacuum sensor circuits are shorted to each other
•  Open circuit in wiring harness between the following terminals:
―  Power brake unit vacuum sensor terminal A—PCM terminal 2BG
―  Power brake unit vacuum sensor terminal B—PCM terminal 2Q
―  Power brake unit vacuum sensor terminal C—PCM terminal 2AH
•  Power brake unit vacuum sensor malfunction
•  PCM malfunction

Diagnostic Procedure

STEP

INSPECTION

ACTION

1
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Verify related Service Information availability.
•  Is any related Service Information available?
Yes
Perform repair or diagnosis according to the available Service Information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
2
VERIFY RELATED PENDING CODE AND/OR DTC
•  Switch the ignition off, then ON (engine off).
•  Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure.
•  Are any other PENDING CODEs and/or DTCs present?
Yes
Go to the applicable PENDING CODE or DTC inspection.
No
Go to the next step.
3
INSPECT POWER BRAKE UNIT VACUUM SENSOR CONNECTOR CONDITION
•  Switch the ignition off.
•  Disconnect the power brake unit vacuum sensor connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to Step 10.
No
Go to the next step.
4
INSPECT POWER BRAKE UNIT VACUUM SENSOR CIRCUIT FOR SHORT TO GROUND
•  Verify that the power brake unit vacuum sensor connector is disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side) and body ground:
―  Power brake unit vacuum sensor terminal A
―  Power brake unit vacuum sensor terminal B
•  Is there continuity?
Yes
If the short to ground circuit could be detected in the wiring harness:
•  Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
―  Power brake unit vacuum sensor terminal A—PCM terminal 2BG
―  Power brake unit vacuum sensor terminal B—PCM terminal 2Q
If there is a common connector:
―  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
―  Repair or replace the malfunctioning part.
If there is no common connector:
―  Repair or replace the wiring harness which has a short to ground.
If the short to ground circuit could not be detected in the wiring harness:
•  Replace the PCM (short to ground in the PCM internal circuit).
Go to Step 10.
No
Go to the next step.
5
INSPECT PCM CONNECTOR CONDITION
•  Disconnect the PCM connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to Step 10.
No
Go to the next step.
6
INSPECT POWER BRAKE UNIT VACUUM SENSOR SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY
•  Verify that the power brake unit vacuum sensor and PCM connectors are disconnected.
•  Switch the ignition ON (engine off).
Note
•  Another DTC may be stored by the PCM detecting an open circuit.
•  Measure the voltage at the power brake unit vacuum sensor terminal B (wiring harness-side).
•  Is the voltage 0 V?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between power brake unit vacuum sensor terminal B and PCM terminal 2Q.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to power supply.
Go to Step 10.
7
INSPECT POWER BRAKE UNIT VACUUM SENSOR CIRCUITS FOR SHORT TO EACH OTHER
•  Verify that the power brake unit vacuum sensor and PCM connectors are disconnected.
•  Switch the ignition off.
•  Inspect for continuity between power brake unit vacuum sensor terminals A, B and C (wiring harness-side).
•  Is there continuity?
Yes
Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
•  Power brake unit vacuum sensor terminal A—PCM terminal 2BG
•  Power brake unit vacuum sensor terminal B—PCM terminal 2Q
•  Power brake unit vacuum sensor terminal C—PCM terminal 2AH
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to each other.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to each other.
Go to Step 10.
No
Go to the next step.
8
INSPECT POWER BRAKE UNIT VACUUM SENSOR CIRCUIT FOR OPEN CIRCUIT
•  Verify that the power brake unit vacuum sensor and PCM connectors are disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side):
―  Power brake unit vacuum sensor terminal A—PCM terminal 2BG
―  Power brake unit vacuum sensor terminal B—PCM terminal 2Q
―  Power brake unit vacuum sensor terminal C—PCM terminal 2AH
•  Is there continuity?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
•  Power brake unit vacuum sensor terminal A—PCM terminal 2BG
•  Power brake unit vacuum sensor terminal B—PCM terminal 2Q
•  Power brake unit vacuum sensor terminal C—PCM terminal 2AH
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
Go to Step 10.
9
INSPECT POWER BRAKE UNIT VACUUM SENSOR
•  Is there any malfunction?
Yes
Replace the power brake unit vacuum sensor, then go to the next step.
No
Go to the next step.
10
VERIFY DTC TROUBLESHOOTING COMPLETED
•  Always reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Perform the KOEO or KOER self test.
•  Is the same DTC present?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the PCM.
Go to the next step.
No
Go to the next step.
11
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
No
DTC troubleshooting completed.