DTC P0555:00 [SKYACTIV-D 1.5]

id0102q2950200

DTC P0555:00

Power brake unit vacuum sensor circuit problem
DETECTION CONDITION
•  The PCM monitors the power brake unit vacuum sensor signal voltage. If the PCM detects the power brake unit vacuum sensor voltage is below 0.077 V or above 4.96 V, the PCM determines that the power brake unit vacuum sensor circuit has problem.
Diagnostic support note
•  This is an intermittent monitor (other).
•  The check engine light does not illuminate.
•  FREEZE FRAME DATA is not available.
•  Snapshot data is available.
•  DTC is stored in the PCM memory.
FAIL-SAFE FUNCTION
•  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 2AK
―  Power brake unit vacuum sensor terminal C—PCM terminal 2BC
•  PCM connector or terminals malfunction
•  Short to power supply in wiring harness between power brake unit vacuum sensor terminal C and PCM terminal 2BC
•  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 2AK
―  Power brake unit vacuum sensor terminal C—PCM terminal 2BC
―  Power brake unit vacuum sensor terminal B—PCM terminal 2BD
•  Power brake unit vacuum sensor malfunction
•  PCM malfunction

Diagnostic Procedure

STEP

INSPECTION

ACTION
1
RECORD VEHICLE STATUS AT TIME OF DTC DETECTION TO UTILIZE WITH REPEATABILITY VERIFICATION
Note
•  Recording can be facilitated using the screen capture function of the PC.
•  Record the snapshot data on the repair order.
—
Go to the next step.
2
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.
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 C
•  Is there continuity?
Yes
Disconnect the PCM connector and inspect the wiring harness for short to ground.
•  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 2AK
•  Power brake unit vacuum sensor terminal C—PCM terminal 2BC
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 C (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 C and PCM terminal 2BC.
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, C and B (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 2AK
•  Power brake unit vacuum sensor terminal C—PCM terminal 2BC
•  Power brake unit vacuum sensor terminal B—PCM terminal 2BD
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 2AK
―  Power brake unit vacuum sensor terminal C—PCM terminal 2BC
―  Power brake unit vacuum sensor terminal B—PCM terminal 2BD
•  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 2AK
•  Power brake unit vacuum sensor terminal C—PCM terminal 2BC
•  Power brake unit vacuum sensor terminal B—PCM terminal 2BD
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
•  Reconnect all disconnected connectors.
•  Inspect the power brake unit vacuum sensor.
•  Is there any malfunction?
Yes
Replace the power brake unit vacuum sensor, then go to the next step.
(See POWER BRAKE UNIT VACUUM SENSOR REMOVAL/INSTALLATION.)
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 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.
(See DTC TABLE [SKYACTIV-D 1.5].)
No
DTC troubleshooting completed.