[ Model - ECLIPSE CROSS / Year - 2018 ]
2018 / ECLIPSE CROSS / EC - Workshop Manual
13 -FUEL > 13A-DIRECT INJECTION AND MULTIPOINT FUEL INJECTION (DI AND MPI) > TROUBLESHOOTING > SYMPTOM PROCEDURES > ENGINE-ECU POWER SUPPLY, ENGINE CONTROL RELAY, IGNITION SWITCH-IG1 SYSTEM
Inspection Procedure 24: Engine-ECU Power Supply, Engine Control Relay, Ignition Switch-IG1 System
 
 
 
 
OPERATION
  • Battery voltage is applied to the engine control relay.
  • Engine-ECU connector terminal C/R applies current to the engine control relay coil by turning ON the power transistor in the unit in order to turn the relay ON.
  • When the engine control relay is turned ON, the battery power will be supplied from the engine control relay to the engine-ECU, sensor and actuator.
 
 
FUNCTION
  • When the ignition switch ON signal is input into the engine-ECU via ETACS-ECU, the engine-ECU turns ON the engine control relay. This causes battery voltage to be supplied to the engine-ECU, sensor and actuator.
 
 
PROBABLE CAUSES
  • Failed battery
  • Failed engine control relay
  • Failed ignition switch <Vehicles without KOS>
  • Failed KOS&OSS-ECU <Vehicles with KOS>
  • Open/short circuit or harness damage in engine control relay circuit, or loose connector contact.
  • Open/short circuit or harness damage in ignition switch (IG1) circuit, or loose connector contact.
  • Open circuit or harness damage in engine-ECU earth circuit, or loose connector contact.
  • Failed ETACS-ECU
  • Failed engine-ECU
 
 
DIAGNOSIS PROCEDURE
STEP 1. Check battery.
  • Battery check (Refer to GROUP 54A - Battery - On-vehicle Service - Battery Test ).
Is the check result normal?
Go to Step 2.
Replace the battery.
 
STEP 2. Check engine control relay itself.
  • Engine control relay continuity check (Refer to ).
Is the check result normal?
Go to Step 3.
Replace the engine control relay.
 
STEP 3. Perform voltage measurement at engine control relay connector
  • Remove relay, and measure at relay box side.
  • Voltage between terminal power supply line and body earth
OK: System voltage
Is the check result normal?
Go to Step 4.
Repair the connector(s), or check and repair of open circuit in power supply line between battery and engine control relay connector.
 
STEP 4. Perform voltage measurement at engine-ECU connector.
  • Disconnect connector, and measure at harness side.
  • Voltage between terminal C/R and body earth.
OK: System voltage
Is the check result normal?
Go to Step 5.
Repair the connector(s), or check and repair of open circuit in C/R line between engine control relay connector and engine-ECU connector.
 
STEP 5. Perform voltage measurement at engine-ECU connector.
  • Disconnect connector, and measure at harness side.
  • Short-circuit engine-ECU harness side connector terminal C/R line to body earth.
  • Voltage between terminal BAT1 line and body earth.
OK: System voltage
Is the check result normal?
Go to Step 8.
Go to Step 6.
 
STEP 6. Check of short to earth, and open circuit in BAT1 line between engine control relay connector and engine-ECU connector.
Is the check result normal?
Go to Step 7.
Repair the connector(s) or wiring harness.
 
STEP 7. Check of damage in power supply line between the battery and engine control relay connector.
Is the check result normal?
Repair the connector(s), or check and repair of damage in C/R line between engine control relay connector and engine-ECU connector.
Repair the connector(s) or wiring harness.
 
STEP 8. Check of damage in BAT1 line between engine control relay connector and engine-ECU connector.
Is the check result normal?
Go to Step 9.
Repair the connector(s) or wiring harness.
 
STEP 9. Check of damage in power supply line between battery and engine control relay connector.
Is the check result normal?
Go to Step 10.
Repair the connector(s) or wiring harness.
 
STEP 10. Perform voltage measurement at engine-ECU connector.
  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal IGN and body earth.
OK: System voltage
Is the check result normal?
YES : Go to Step 15.
Go to Step 11.
 
STEP 11. Perform voltage measurement at ETACS-ECU connector.
  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal IGS and body earth.
OK: System voltage
Is the check result normal?
Go to Step 14.
Go to Step 12 <Vehicles without KOS>.
NO : Go to Step 13 <Vehicles with KOS>.
 
STEP 12. Check ignition switch itself.
  • Ignition switch check (Refer to GROUP 54A - Ignition Switch - Inspection - Ignition Switch Check ).
Is the check result normal?
Repair the connector(s), or check and repair of short to earth, and open circuit in IG1 to IGS line between ignition switch connector and ETACS-ECU connector.
Replace the ignition switch.
 
STEP 13. Check of short to earth, and open circuit in IG1 to IGS line between KOS&OSS-ECU connector and ETACS-ECU connector.
Is the check result normal?
Perform troubleshooting of OSS System (Refer to GROUP 42B - Troubleshooting - Trouble Symptom Chart ).
Repair the connector(s) or wiring harness.
 
STEP 14. Continuity check on ETACS-ECU connectors
  • Disconnect connectors, and measure at the ETACS-ECU side.
  • Continuity test between terminal IGS and EIG1.
noteConnect the (+) side of circuit tester to terminal EIG1.
OK: Continuity
Is the check result normal?
Repair the connector(s), or check and repair of short to earth, and open circuit in EIG1 to IGN line between ETACS-ECU connector and engine-ECU connector.
Replace the ETACS-ECU.
 
STEP 15. Check of damage in EIG1 to IGN line between ETACS-ECU connector and engine-ECU connector.
Is the check result normal?
Go to Step 16.
Repair the connector(s) or wiring harness.
 
STEP 16. Continuity check on ETACS-ECU connectors
  • Disconnect connectors, and measure at the ETACS-ECU side.
  • Continuity test between terminal IGS and EIG1.
noteConnect the (+) side of circuit tester to terminal EIG1.
OK: Continuity
Is the check result normal?
Go to Step 17 <Vehicles without KOS>.
Go to Step 18 <Vehicles with KOS>.
Replace the ETACS-ECU.
 
STEP 17. Check of damage in IG1 to IGS line between ignition switch connector and ETACS-ECU connector.
Is the check result normal?
Go to Step 19.
Repair the connector(s) or wiring harness.
 
STEP 18. Check of damage in IG1 to IGS line between KOS&OSS-ECU connector and ETACS-ECU connector.
Is the check result normal?
Go to Step 19.
Repair the connector(s) or wiring harness.
 
STEP 19. Check of open circuit, and damage in GNDB, GNDE line between engine-ECU connector and body earth.
Is the check result normal?
Replace the engine-ECU.
Repair the connector(s) or wiring harness.