[ 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 > A/C COMPRESSOR RELAY SYSTEM
Inspection Procedure 27: A/C Compressor Relay System
 
 
 
 
OPERATION
  • Battery voltage is applied to the A/C compressor relay.
  • Engine-ECU connector terminal AC/R applies current to the A/C compressor relay coil by turning ON the power transistor in the unit in order to turn the relay ON.
  • When the A/C compressor relay turns ON, battery voltage is supplied by the A/C compressor relay to the A/C compressor assembly.
 
 
FUNCTION
  • When the A/C switch ON signal is input into the engine-ECU, the engine-ECU turns ON the A/C compressor relay. This causes battery voltage to be supplied to the A/C compressor assembly and the magnetic clutch actuates.
 
 
PROBABLE CAUSES
  • Failed A/C compressor relay
  • Failed A/C compressor assembly
  • Open/short circuit or harness damage in A/C compressor relay circuit, or loose connector contact.
  • Failed engine-ECU
 
 
DIAGNOSIS PROCEDURE
STEP 1. Check A/C compressor relay itself.
  • A/C compressor relay check (Refer to GROUP 55 - On-vehicle Service - Relay Check ).
Is the check result normal?
Go to Step 2.
Replace the A/C compressor relay.
 
STEP 2. Perform voltage measurement at A/C compressor relay.
  • Disconnect 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 3.
Repair the connector(s), or check and repair of short to earth, and open circuit in power supply line between battery and A/C compressor relay connector.
 
STEP 3. Check of damage in power supply line between battery and A/C compressor relay connector.
Is the check result normal?
Go to Step 4.
Repair the connector(s) or wiring harness.
 
STEP 4. Perform voltage measurement at engine-ECU connector.
  • Disconnect connector, and measure at harness side.
  • Voltage between terminal AC/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 short to earth, and open circuit in AC/R line between A/C compressor relay connector and engine-ECU connector.
 
STEP 5. Check of damage in AC/R line between A/C compressor relay connector and engine-ECU connector.
Is the check result normal?
Go to Step 6.
Repair the connector(s) or wiring harness.
 
STEP 6. Check of open circuit, short circuit, and damage in power supply line between A/C compressor relay connector and A/C compressor assembly connector.
Is the check result normal?
Go to Step 7.
Repair the connector(s) or wiring harness.
 
STEP 7. Check A/C compressor clutch operating conditions.
  • Disconnect engine-ECU connector, and short-circuit harness side terminal AC/R to the body earth.
OK: A/C compressor clutch operates.
Is the check result normal?
Replace the engine-ECU.
Replace the A/C compressor assembly.