2019 Infiniti M35 V6-3.5L (VQ35HR) Diagnostic and Repair Information Page 352
1. Start engine and let it idle.
2. Listen to each fuel injector operating sound.
Clicking sound should be heard.
Is the inspection result normal?
YES - GO TO 8.
NO - Perform trouble diagnosis for FUEL INJECTOR, See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Injector/Testing and
Inspection/Component Tests and General Diagnostics/Diagnosis Procedure.
8.CHECK FUEL INJECTOR
1. Turn ignition switch OFF.
2. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
3. Disconnect all fuel injector harness connectors.
4. Remove fuel tube assembly. See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Rail/Service and Repair/Removal and
Installation.
Keep fuel hose and all fuel injectors connected to fuel tube.
5. For DTC P0171, reconnect fuel injector harness connectors on bank 1.
For DTC P0174, reconnect fuel injector harness connectors on bank 2.
6. Disconnect all ignition coil harness connectors.
7. Prepare pans or saucers under each fuel injector.
8. Crank engine for approximately 3 seconds.
For DTC P0171, check that fuel sprays out from fuel injectors on bank 1.
For DTC P0174, check that fuel sprays out from fuel injectors on bank 2.
Fuel should be sprayed evenly for each fuel injector.
Is the inspection result normal?
YES - GO TO 9.
NO - Replace fuel injectors from which fuel does not spray out. Always replace O-ring with new ones.
9.CHECK INTERMITTENT INCIDENT
See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Initial Inspection and Diagnostic Overview/Trouble
Diagnosis For Intermittent Incident/Description.
- INSPECTION END
P0172
P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
DTC Logic
DTC DETECTION LOGIC
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on
the mixture ratio feedback signal from air fuel ratio (A/F) sensor 1. The ECM calculates the necessary compensation to correct the offset between
the actual and the theoretical ratios.
In case the amount of the compensation value is extremely large (the actual mixture ratio is too rich), the ECM judges the condition as the fuel
injection system malfunction and illuminates the MIL (2 trip detection logic).
