2019 Infiniti M35 V6-3.5L (VQ35HR) Diagnostic and Repair Information Page 429
10.CHECK FUEL PRESSURE
1. Install all removed parts.
2. Check fuel pressure. See: Engine, Cooling and Exhaust/Engine/Tune-up and Engine Performance Checks/Fuel Pressure/Testing and
Inspection.
Is the inspection result normal?
YES - GO TO 12.
NO - GO TO 11.
11.DETECT MALFUNCTIONING PART
Check fuel hoses and fuel tubes for clogging.
Is the inspection result normal?
YES - Replace "fuel filter and fuel pump assembly".
NO - Repair or replace malfunctioning part.
12.CHECK IDLE SPEED AND IGNITION TIMING
Check idle speed and ignition timing.
For procedure, See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Initial Inspection and Diagnostic
Overview/Basic Inspection.
For specification, See: Engine, Cooling and Exhaust/Engine/Tune-up and Engine Performance Checks/Idle Speed/Specifications and See: Engine,
Cooling and Exhaust/Engine/Tune-up and Engine Performance Checks/Ignition Timing/Specifications.
Is the inspection result normal?
YES - GO TO 13.
NO - Follow the See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Initial Inspection and Diagnostic
Overview/Basic Inspection.
13.CHECK AIR FUEL RATIO (A/F) SENSOR 1 INPUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect corresponding A/F sensor 1 harness connector.
3. Disconnect ECM harness connector.
4. Check the continuity between A/F sensor 1 harness connector and ECM harness connector.
5. Check the continuity between A/F sensor 1 harness connector or ECM harness connector and ground.
6. Also check harness for short to power.
Is the inspection result normal?
YES - GO TO 14.
NO - Repair open circuit, short to ground or short to power in harness or connectors.
14.CHECK A/F SENSOR 1 HEATER
See: P Code Charts/P0031.
Is the inspection result normal?
YES - GO TO 15.
NO - Replace (malfunctioning) A/F sensor 1.
15.CHECK MASS AIR FLOW SENSOR
With CONSULT-III
Check mass air flow sensor signal in "DATA MONITOR" mode with CONSULT-III.
For specification, See: Powertrain Management/Computers and Control Systems/Air Temperature Sensor ( Ambient / Intake )/Specifications.
