LEMON Manuals: Even more car manuals for everyone
Home >> Mazda >> 2022 >> MX-5 Miata RF Club >> Repair and Diagnosis >> Brakes >> Mechanical - Hydraulic >> On-Board Diagnostics - Electric Vacuum Pump (EVP) >> DTC U3003-16/U3003-17: EVP Control Unit Power Supply Low Input [EVP Control Unit] >> Diagnostic Procedure

Diagnostic Procedure

DTC U3003:16/U3003:17 (EVP CONTROL UNIT) DIAGNOSTIC PROCEDURE

Step INSPECTION Action
1 VERIFY PCM DTC 
 Yes Go to the applicable DTC inspection.
(See DTC TABLE [PCM] .) DTC troubleshooting completed, then go to the next Step.
No Go to the next Step.
2 INSPECT BATTERY 
 Yes Charge or replace the battery, then go to Step 7. (See BATTERY RECHARGING .)
(See BATTERY REMOVAL/INSTALLATION .)
No Go to the next Step.
3 INSPECT GENERATOR 
 Yes Replace the generator, then go to Step 7.
(See GENERATOR REMOVAL/INSTALLATION .)
No Go to the next Step.
4 INSPECT FUSE CONDITION 
  • Is the fuse (EVPS 30A) normal?
 Yes Go to the next Step.
No
  • If the fuse is blown:
    • Refer to the wiring diagram and verify whether or not there is a common connector between fuse and EVP control unit terminal A.

    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.
    • Replace the fuse.
  • If the fuse is damaged:
  • Replace the fuse.

    Go to Step 7.
5 INSPECT EVP CONTROL UNIT POWER CIRCUIT FOR OPEN CIRCUIT 
  • Switch the ignition OFF.
  • Disconnect the EVP control unit connector.
  • Switch the ignition ON (engine off).
  • Measure the voltage between EVP control unit terminal A (wiring harness-side)-body ground.
  • Is the voltage 10 V or more?
 Yes Go to the next Step.
No Refer to the wiring diagram and verify whether or not there is a common connector between battery and EVP control unit terminal A.
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 7.
6 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.
7 VERIFY DTC TROUBLESHOOTING COMPLETED 
 Yes Repeat the inspection from Step 1.
If the malfunction recurs, replace the EVP control unit, then go to the next Step.
(See EVP CONTROL UNIT REMOVAL/INSTALLATION .)
No Go to the next Step.
8 VERIFY NO DTC IS PRESENT 
  • Are any DTCs present?
 Yes Go to the applicable DTC inspection. (See DTC TABLE [EVP CONTROL UNIT] .)
No DTC troubleshooting completed.
scientia non olet · About LEMON Manuals