ELECTRIC VACUUM PUMP WARNING LIGHT REMAINS ILLUMINATED [EVP CONTROL UNIT]


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1

Electric vacuum pump warning light remains illuminated

POSSIBLE CAUSE
•  Electric vacuum pump warning light illuminates for emission-related concern (DTC is stored in EVP control unit)
•  Instrument cluster malfunction (malfunction in Electric vacuum pump warning light illumination circuit)
•  EVP control unit malfunction
―  Electric vacuum pump warning light illumination request signal false transmission
•  EVP control unit does not operate.
―  Short to ground or open circuit in wiring harness between battery and EVP control unit terminal A
―  Open circuit in wiring harness between EVP control unit terminal G and body ground
•  Electric vacuum pump control unit related HS-CAN communication error

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY COMMUNICATION CONDITION OF ELECTRIC VACUUM PUMP CONTROL
•  Implement the network test using the M-MDS.
•  Is the EVP (electric vacuum pump control unit) test result displayed as pass?
Yes
Go to the next step.
No
Go to Step 4.
2
VERIFY EVP CONTROL UNIT DTCs
•  Switch the ignition ON (engine off).
•  Using the M-MDS, perform the EVP control unit DTC inspection.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
No
Go to the next step.
3
DETERMINE IF MALFUNCTION CAUSE IS INSTRUMENT CLUSTER OR EVP CONTROL UNIT
•  Turn on and off all the indicator lights and warning lights in the instrument cluster using the simulation function WL+IL in the M-MDS instrument cluster.
•  Does the electric vacuum pump warning light turn on/off according to the simulation operation?
Yes
Replace the EVP control unit, then go to the next step.
Go to Step 7.
No
Replace the instrument cluster.
Go to Step 7.
4
INSPECT EVP CONTROL UNIT POWER SUPPLY
•  Inspect for EVP control unit power supply as followings:
―  Battery voltage
―  Fuse (EVPS 30A)
―  Wiring harness and connectors between battery and EVP control unit terminal A (without i-ELOOP)
―  Wiring harness and connectors between DC-DC converter terminal 4A and EVP control unit terminal A (with i-ELOOP)
―  EVP control unit connector for poor connection (such as damaged/pulled-out pins, corrosion).
•  Are inspection results normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part.
Go to Step 7.
5
INSPECT EVP CONTROL UNIT GROUND CIRCUIT FOR OPEN CIRCUIT OR POOR GROUND
•  Switch the ignition OFF.
•  Disconnect the EVP control unit connector.
•  Measure the resistance between EVP control unit terminal G (wiring harness-side) and body ground.
•  Is the resistance 0—1 ohm?
Yes
Go to the next step.
No
•  If the open circuit could be detected in the wiring harness:
―  Refer to the wiring diagram and verify whether or not there is a common connector between EVP control unit terminal G and body ground.
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 the next step.
•  If the resistance is out of specification:
―  Refer to the wiring diagram and verify whether or not there is a common connector between EVP control unit terminal G and body ground.
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 poor ground.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a poor ground.
―  Go to the next step.
6
INSPECT HS-CAN RELATED WIRING HARNESS
•  Are inspection results normal?
Yes
Replace the EVP control unit, then go to the next step.
Go to the next step.
No
Repair or replace the malfunctioning part.
Go to the next step.
7
VERIFY DTC TROUBLESHOOTING COMPLETED
•  Has the symptom troubleshooting been completed?
Yes
Troubleshooting completed. (explain the contents of the servicing to the customer)
No
Find the malfunctioning location referring to Action for Non-Repeatable Malfunction.