Ignition Circuit [11/2022 - ]: Procedure
WARNING: This page is about a different car, the 2025 Toyota Corolla Cross, 2024 Toyota Corolla Cross, and 2023 Toyota Corolla Cross. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK TERMINAL VOLTAGE (POWER SOURCE OF IGNITION COIL ASSEMBLY)
*a Front view of wire harness connector
(to Ignition Coil Assembly)- Disconnect the ignition coil assembly connectors.
- Turn the ignition switch to ON.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition C1-1 (+B) - C1-3 (GND) Ignition switch ON 11 to 14 V C3-1 (+B) - C3-3 (GND) Ignition switch ON 11 to 14 V C5-1 (+B) - C5-3 (GND) Ignition switch ON 11 to 14 V C7-1 (+B) - C7-3 (GND) Ignition switch ON 11 to 14 V Result
Proceed to OK NG
Result:
NG
See step 3
Result:
OK
See step 2
- CHECK HARNESS AND CONNECTOR (IGNITION COIL ASSEMBLY - ECM)
- Disconnect the ignition coil assembly connectors.
- Disconnect the ECM connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition C1-2 (IGT1) - C139-49 (IGT1) Always Below 1 Ω C3-2 (IGT2) - C139-48 (IGT2) Always Below 1 Ω C5-2 (IGT3) - C139-47 (IGT3) Always Below 1 Ω C7-2 (IGT4) - C139-46 (IGT4) Always Below 1 Ω C1-2 (IGT1) or C139-49 (IGT1) - Body ground and other terminals Always 10 kΩ or higher C3-2 (IGT2) or C139-48 (IGT2) - Body ground and other terminals Always 10 kΩ or higher C5-2 (IGT3) or C139-47 (IGT3) - Body ground and other terminals Always 10 kΩ or higher C7-2 (IGT4) or C139-46 (IGT4) - Body ground and other terminals Always 10 kΩ or higher Result
Proceed to OK NG
Result:
OK
REPLACE ECM. Refer to REMOVAL [11/2022 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
- CHECK HARNESS AND CONNECTOR (IGNITION COIL ASSEMBLY - BODY GROUND)
- Disconnect the ignition coil assembly connectors.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition C1-3 (GND) - Body ground Always Below 1 Ω C3-3 (GND) - Body ground Always Below 1 Ω C5-3 (GND) - Body ground Always Below 1 Ω C7-3 (GND) - Body ground Always Below 1 Ω Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 4
- CHECK HARNESS AND CONNECTOR (IGP-MAIN RELAY - IGNITION COIL ASSEMBLY)
- Remove the IGP-MAIN relay from the No. 1 engine room relay block.
- Disconnect the ignition coil assembly connectors.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition 3 (IGP-MAIN relay) - C1-1 (+B) Always Below 1 Ω 3 (IGP-MAIN relay) - C3-1 (+B) Always Below 1 Ω 3 (IGP-MAIN relay) - C5-1 (+B) Always Below 1 Ω 3 (IGP-MAIN relay) - C7-1 (+B) Always Below 1 Ω 3 (IGP-MAIN relay) or C1-1 (+B) - Body ground and other terminals Always 10 kΩ or higher 3 (IGP-MAIN relay) or C3-1 (+B) - Body ground and other terminals Always 10 kΩ or higher 3 (IGP-MAIN relay) or C5-1 (+B) - Body ground and other terminals Always 10 kΩ or higher 3 (IGP-MAIN relay) or C7-1 (+B) - Body ground and other terminals Always 10 kΩ or higher Result
Proceed to OK NG
Result:
OK
GO TO ECM POWER SOURCE CIRCUIT. Refer to ECM Power Source Circuit [11/2022 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR