[ Model - ECLIPSE CROSS / Year - 2018 ]
2018 / ECLIPSE CROSS / EC - Workshop Manual
54 -CHASSIS ELECTRICAL > 54A-CHASSIS ELECTRICAL > HANDS FREE-ECU > SYMPTOM PROCEDURES > CHECK THE HANDS-FREE-ECU POWER SUPPLY CIRCUIT.
Inspection Procedure 1: Check the hands free-ECU power supply circuit.
 
 
cautionBefore replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.
 
 
CIRCUIT OPERATION
  • The hands free-ECU is energised via the fusible link.
  • The ACC signal is received through the radio and CD player <vehicles with radio and CD player> or multivision display <vehicles with MMCS>.
 
 
 
PROBABLE CAUSES
  • Malfunction of the hands free-ECU
  • Malfunction of the DC/DC converter
  • Malfunction of the radio and CD player <Vehicles with radio and CD player>
  • Malfunction of the multivision display <Vehicles with MMCS>
  • Damaged harness wires and connectors
 
 
 
 
DIAGNOSIS PROCEDURE
STEP 1. Check the DC/DC converter.
Check the continuity of the DC/DC converter.
Is the check result normal?
Go to Step 2.
Replace the DC/DC converter.
 
STEP 2. Resistance measurement at hands free-ECU connector (GND terminal).
(1) Disconnect hands free-ECU connector, and measure at the wiring harness side.
(2) Check the continuity between GND terminal and earth.
OK: Continuity exists (2 Ω or less)
Is the check result normal?
Go to Step 4.
Go to Step 3.
 
STEP 3. Check of open circuit in GND line between hands free-ECU connector and body earth.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
Repair the connector(s) or wiring harness.
 
STEP 4. Voltage measurement at hands free-ECU connector (+B terminal).
(1) Disconnect hands free-ECU connector, and measure at the wiring harness side.
(2) Measure the voltage between +B terminal and body earth.
OK: System voltage
Is the check result normal?
Go to Step 6.
Go to Step 5.
 
STEP 5. Check of short to power supply, short to earth, and open circuit in +B line between DC/DC converter connector and hands free-ECU connector.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Repair the connector(s) or wiring harness.
 
STEP 6. Voltage measurement at hands free-ECU connector (ACC terminal).
(1) Disconnect hands free-ECU connector, and measure at the wiring harness side.
(2) Turn the ignition switch to "ACC" position.
(3) Measure the voltage between ACC terminal and body earth.
OK: System voltage
Is the check result normal?
Replace the hands free-ECU.
Go to Step 7.
 
STEP 7. Check of short to power supply, short to earth, and open circuit in ACC line between hands free-ECU connector and radio and CD player <vehicles with radio and CD player> or multivision display <vehicles with MMCS> connector.
Is the check result normal?
Replace the radio and CD player <vehicles with radio and CD player> or multivision display <vehicles with MMCS>.
Repair the connector(s) or wiring harness.