ECM Power Source Circuit: Procedure
- CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - BODY GROUND)
- Disconnect the hybrid vehicle control ECU connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition C28-14 (E1) - Body ground Always Below 1 Ω - Reconnect the hybrid vehicle control ECU connector.
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
- INSPECT HYBRID VEHICLE CONTROL ECU (IGSW VOLTAGE)
- Disconnect the hybrid vehicle control ECU connector.
- Turn the power switch on (IG).
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Switch Condition Specified Condition A58-57 (IGSW) - Body ground Power switch on (IG) 11 to 14 V TEXT IN ILLUSTRATION*1 Front view of wire harness connector
(to Hybrid Vehicle Control ECU) - Reconnect the hybrid vehicle control ECU connector.
NG → See step 7
OK: Go to next step
- INSPECT RELAY (IGCT RELAY)
- Remove the IGCT relay from the engine room relay block.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition 3 - 5 No battery voltage applied across terminals 1 and 2 10 kΩ or higher Battery voltage applied across terminals 1 and 2 Below 1 Ω - Reinstall the IGCT relay.
NG → REPLACE RELAY (IGCT RELAY)
OK: Go to next step
- CHECK HARNESS AND CONNECTOR (IGCT RELAY - HYBRID VEHICLE CONTROL ECU)
- Remove the IGCT relay from the engine room relay block.
- Disconnect the hybrid vehicle control ECU connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open)
Tester Connection Condition Specified Condition IGCT relay terminal 5 - A58-1 (+B2) Always Below 1 Ω IGCT relay terminal 5 - A58-2 (+B1) Always Below 1 Ω IGCT relay terminal 1 - A58-93 (MREL) Always Below 1 Ω Standard Resistance (Check for Short)
Tester Connection Condition Specified Condition IGCT relay terminal 5 or A58-1 (+B2) - Body ground Always 10 kΩ or higher IGCT relay terminal 5 or A58-2 (+B1) - Body ground Always 10 kΩ or higher IGCT relay terminal 1 or A58-93 (MREL) - Body ground Always 10 kΩ or higher - Reconnect the hybrid vehicle control ECU connector.
- Reinstall the IGCT relay.
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
- CHECK HARNESS AND CONNECTOR (IGCT RELAY - BATTERY)
- Remove the IGCT relay from the engine room relay block.
- Disconnect the negative battery terminal.
- Disconnect the positive battery terminal.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open)
Tester Connection Condition Specified Condition IGCT relay terminal 3 - Battery positive terminal Always Below 1 Ω - Reinstall the IGCT relay.
- Reconnect the positive battery terminal.
- Reconnect the negative battery terminal.
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
- CHECK HARNESS AND CONNECTOR (IGCT RELAY - BODY GROUND)
- Remove the IGCT relay from the engine room relay block.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open)
Tester Connection Condition Specified Condition IGCT relay terminal 2 - Body ground Always Below 1 Ω - Reinstall the IGCT relay.
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK → See step 13
- INSPECT INTEGRATION RELAY (IG2 RELAY)
- Inspect the IG2 relay. Refer to INSPECTION .
NG → See step 12
OK: Go to next step
- CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY (IG2 RELAY) - HYBRID VEHICLE CONTROL ECU)
- Disconnect the hybrid vehicle control ECU connector.
- Remove the integration relay from the engine room relay block.
- Disconnect the integration relay connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open)
Tester Connection Condition Specified Condition 1A-4 - A58-57 (IGSW) Always Below 1 Ω Standard Resistance (Check for Short)
Tester Connection Condition Specified Condition 1A-4 or A58-57 (IGSW) - Body ground Always 10 kΩ or higher - Reconnect the hybrid vehicle control ECU connector.
- Reconnect the integration relay connector.
- Reinstall the integration relay.
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
- CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY (IG2 RELAY) - BATTERY)
- Remove the integration relay from the engine room relay block.
- Disconnect the integration relay connector.
- Disconnect the negative battery terminal.
- Disconnect the positive battery terminal.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open)
Tester Connection Condition Specified Condition 1C-1 - Battery positive terminal Always Below 1 Ω Standard Resistance (Check for Short)
Tester Connection Condition Specified Condition 1C-1 or Battery positive terminal - Body ground Always 10 kΩ or higher - Reconnect the integration relay connector.
- Reinstall the integration relay.
- Reconnect the positive battery terminal.
- Reconnect the negative battery terminal.
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
- CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY (IG2 RELAY) - BODY GROUND)
- Remove the integration relay from the engine room relay block.
- Disconnect the integration relay connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open)
Tester Connection Condition Specified Condition 1A-3 - Body ground Always Below 1 Ω - Reconnect the integration relay connector.
- Reinstall the integration relay.
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
- CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - INTEGRATION RELAY (IG2 RELAY))
- Remove the integration relay from the engine room relay block.
- Disconnect the integration relay connector.
- Disconnect the power management control ECU connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open)
Tester Connection Condition Specified Condition F51-8 (IG2D) - 1A-2 Always Below 1 Ω Standard Resistance (Check for Short)
Tester Connection Condition Specified Condition F51-8 (IG2D) or 1A-2 - Body ground Always 10 kΩ or higher - Reconnect the integration relay connector.
- Reinstall the integration relay.
- Reconnect the power management control ECU connector.
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK → See step 14
- REPLACE INTEGRATION RELAY (IG2 RELAY). Refer to REMOVAL
- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to PROBLEM SYMPTOMS TABLE
- CHECK SMART ACCESS SYSTEM WITH PUSH-BUTTON START. Refer to HOW TO PROCEED WITH TROUBLESHOOTING