DTC P12D5-01: Fuel Pump Control General Electrical Failure [11/2021 - ]: Procedure
WARNING: This page is about a different car, the 2025 Lexus NX 350, 2024 Lexus NX 350, 2023 Lexus NX 350, and 2022 Lexus NX 350. However, it is still accessible from the selected car via links, so may be relevant.
- INSPECT FUEL PUMP CONTROL ECU
*a Component without harness connected
(Fuel Pump Control ECU)- - - Remove the fuel pump control ECU.
Refer to REMOVAL [11/2021 - ]
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition G105-2 (FPU) - G106-3 (GND) Always 2 kΩ or higher G105-3 (FPV) - G106-3 (GND) Always 2 kΩ or higher G105-4 (FPW) - G106-3 (GND) Always 2 kΩ or higher HINT:
This procedure checks for an internal short of the fuel pump control ECU when its transistor is stuck on.
Result
Proceed to OK NG
Result:
NG
REPLACE FUEL PUMP CONTROL ECU. Refer to REMOVAL [11/2021 - ]
Result:
OK
See step 2
- Remove the fuel pump control ECU.
- PERFORM ACTIVE TEST USING GTS (FUEL PUMP SINGLE PHASE ENERGIZATION)
*a Component without harness connected
(Fuel Pump Control ECU)- Disconnect the G105 fuel pump control ECU connector.
- Operate the fuel pump control ECU using the Active Test function and measure the voltage according to the value(s) in the table below.
Powertrain > Engine > Active Test
Tester Display Fuel Pump Single Phase Energization Standard Voltage
Tester Connection GTS Operation Specified Condition G105-2 (FPU) - Body ground U Phase 4.4 to 8.4 V* G105-3 (FPV) - Body ground 8 to 15.5 V G105-4 (FPW) - Body ground 8 to 15.5 V G105-3 (FPV) - Body ground V Phase 4.4 to 8.4 V* G105-2 (FPU) - Body ground 8 to 15.5 V G105-4 (FPW) - Body ground 8 to 15.5 V G105-4 (FPW) - Body ground W Phase 4.4 to 8.4 V* G105-2 (FPU) - Body ground 8 to 15.5 V G105-3 (FPV) - Body ground 8 to 15.5 V HINT:
- *: This Active Test limits the fuel pump control ECU output duty cycle to 50%. Therefore, the output voltage of the fuel pump control ECU will be approximately 50% of the power source voltage (+B terminal).
- Before performing this inspection, check that the battery voltage is between 11 and 14 V (not depleted).
Result
Proceed to OK NG
Result:
NG
REPLACE FUEL PUMP CONTROL ECU. Refer to REMOVAL [11/2021 - ]
Result:
OK
See step 3
- CHECK HARNESS AND CONNECTOR (FUEL PUMP CONTROL ECU - FUEL PUMP (FOR LOW PRESSURE SIDE))
- Disconnect the fuel pump control ECU connector.
- Disconnect the fuel pump (for low pressure side) connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition G105-2 (FPU) or G117-3 (BLPU) - Body ground and other terminals Always 10 kΩ or higher G105-3 (FPV) or G117-4 (BLPV) - Body ground and other terminals Always 10 kΩ or higher G105-4 (FPW) or G117-2 (BLPW) - Body ground and other terminals Always 10 kΩ or higher HINT:
Perform "Inspection After Repair" after replacing the fuel pump (for low pressure side).
Refer to INITIALIZATION [11/2021 - ]
Result
Proceed to OK NG
Result:
OK
REPLACE FUEL PUMP (FOR LOW PRESSURE SIDE). Refer to REMOVAL [11/2021 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR