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INSPECTION PROCEDURE 1: PHEV-ECU power supply system malfunction
 
 
 
 
COMMENTS ON TROUBLE SYMPTOM
The power supply or ground circuit to the PHEV-ECU or PHEV-ECU itself is suspected.
 
 
 
TROUBLE JUDGMENT
  • Malfunction of the EV control relay.
  • Malfunction of the PHEV-ECU.
  • Open circuit, short circuit to ground system, damage, or connector poor contact in the PHEV-ECU circuit.
 
 
 
 
DIAGNOSIS
Required Special Tools
  • MB991223: Wiring harness set
  • MB992006: Extra fine probe
STEP 1. Voltage measurement at the PHEV-ECU connector.
(1) Measure by backprobing.
(2) Turn the power supply mode of the electric motor switch to ON.
(3) Measure the voltage between IGCT terminal and body ground.
OK: Approximately 12 volts (battery positive voltage).
(4) Measure the voltage between IGC2 terminal and body ground.
OK: Approximately 12 volts (battery positive voltage).
Is the check result normal?
Go to Step 7.
  • Go to Step 2.
 
STEP 2. EV control relay check
Refer to .
Is the check result normal?
Go to Step 3.
Replace the EV control relay.
 
STEP 3. Resistance measurement at the EV control relay connector.
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Measure the resistance between EV control relay connector (terminal No.1) and body ground.
OK: Continuity exists (2 Ω or less)
Is the check result normal?
Go to Step 4.
Repair the connector or wiring harness.
 
STEP 4. Voltage measurement at the EV control relay connector.
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Measure the voltage between EV control relay connector (terminal No.4) and body ground.
OK: Approximately 12 volts (battery positive voltage).
Is the check result normal?
Go to Step 6.
  • Go to Step 5.
 
STEP 5. Check the power supply line for open circuit and short to ground circuit (Fusible link and the EV control relay).
Check the wiring harness between fusible link 8 and the EV control relay connector (terminal No.4).
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
Repair the connector or wiring harness.
 
STEP 6. Check the power supply line for open circuit and short to ground circuit (EV control relay and PHEV-ECU).
Check the wiring harness between EV control relay connector (terminal No.3) and the PHEV-ECU connector (terminals IGCT, IGC2, CTL).
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
Repair the connector or wiring harness.
 
STEP 7. Voltage measurement at the PHEV-ECU connector.
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Measure the voltage between PHEV-ECU connector (terminal BAT) and body ground.
OK: Approximately 12 volts (battery positive voltage).
Is the check result normal?
Go to Step 9.
  • Go to Step 8.
 
STEP 8. Check the power supply line for open circuit , short to ground circuit and short to power supply circuit (fusible link and PHEV-ECU).
Check the wiring harness between fusible link 6 and the PHEV-ECU connector (terminal BAT).
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
Repair the connector or wiring harness.
 
STEP 9. Resistance measurement at the PHEV-ECU connector.
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Measure the resistance between PHEV-ECU connector (GND, GND2 terminals) and body ground.
OK: Continuity exists (2 Ω or less)
Is the check result normal?
Go to Step 10.
Repair the connector or wiring harness.
 
STEP 10. Retest the system.
Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
Replace the PHEV-ECU (Refer to ).