Ignition Circuit [11/2023 - ]: Procedure
WARNING: This page is about a different car, the 2025 Toyota Corolla Cross and 2024 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) - C144-107 (IGT1) Always Below 1 Ω C3-2 (IGT2) - C144-106 (IGT2) Always Below 1 Ω C5-2 (IGT3) - C144-105 (IGT3) Always Below 1 Ω C7-2 (IGT4) - C144-104 (IGT4) Always Below 1 Ω C1-2 (IGT1) or C144-107 (IGT1) - Body ground and other terminals Always 10 kΩ or higher C3-2 (IGT2) or C144-106 (IGT2) - Body ground and other terminals Always 10 kΩ or higher C5-2 (IGT3) or C144-105 (IGT3) - Body ground and other terminals Always 10 kΩ or higher C7-2 (IGT4) or C144-104 (IGT4) - Body ground and other terminals Always 10 kΩ or higher Result
Proceed to OK NG
Result:
OK
REPLACE ECM. Refer to REMOVAL [11/2023 - ]
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 assembly.
- 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 [11/2023 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR