DTC P1CFA-12: IGB Signal Circuit Short to Auxiliary Battery [11/2021 - ]: Procedure
WARNING: This page is about a different car, the 2025 Lexus NX 350h, 2024 Lexus NX 350h, 2023 Lexus NX 350h, and 2022 Lexus NX 350h. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR)
Refer to PROCEDURE - Step 1
Result
Proceed to OK NG Result:
NG
CONNECT SECURELY
Result:
OK
See step 2
- CHECK CONNECTOR CONNECTION CONDITION (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY))
- Check the connector connection condition of the certification ECU (smart key ECU assembly).
Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [11/2021 - ]
OK
The connector is connected securely and there are no contact problems.
Result
Proceed to OK NG
Result:
NG
CONNECT SECURELY
Result:
OK
See step 3
- Check the connector connection condition of the certification ECU (smart key ECU assembly).
- CHECK HARNESS AND CONNECTOR (IGB TERMINAL VOLTAGE)
- Turn the ignition switch off.
- Measure the voltage according to the value(s) in the table below.
*a Component with harness connected
(Hybrid Vehicle Control ECU)- - Standard Voltage
Tester Connection Condition Specified Condition D67-43 (IGB) - Body ground Ignition switch off Below 1 V Result
Proceed to OK NG
Result:
OK
REPLACE HYBRID VEHICLE CONTROL ECU. Refer to REMOVAL [11/2021 - ]
Result:
NG
See step 4
- CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY))
- Disconnect the certification ECU (smart key ECU assembly) connector.
- Measure the voltage according to the value(s) in the table below.
*a Component with harness connected
(Hybrid Vehicle Control ECU)- - Standard Voltage
Tester Connection Condition Specified Condition D67-43 (IGB) - Body ground Ignition switch off Below 1 V - Reconnect the certification ECU (smart key ECU assembly) connector.
Result
Proceed to OK NG
Result:
OK
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to REMOVAL [11/2021 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR