Understanding DTC P1604
Diagnostic Trouble Code (DTC) P1604 indicates a "Startability Malfunction" in the 2014 Toyota RAV4. This code is stored when the engine fails to start, takes an extended time to start, or stalls shortly after starting, even when the start signal (STA) is present.
The document emphasizes the use of Toyota's Techstream diagnostic tool to analyze freeze frame data, which captures engine conditions at the time the DTC was recorded, aiding in accurate troubleshooting.
It's also noted that running out of fuel can trigger this DTC, highlighting the importance of checking fuel levels as a preliminary step.
Key Troubleshooting Areas
The repair manual outlines a systematic approach to diagnosing P1604, identifying potential issues across various vehicle systems. Common areas and components requiring inspection include:
- Engine Mechanical: Issues like excess engine friction or compression loss.
- Starting System: Battery condition (depletion, voltage fluctuations), starter assembly, and related components like the drive plate and ring gear.
- Engine Control Components: Crankshaft position sensor, camshaft position sensor, and the Engine Control Module (ECM).
- Fuel System: Fuel pump, fuel pump control system, fuel lines, fuel filter, fuel injectors, fuel pressure regulator, and potential fuel leaks.
- Ignition System: Spark plugs, ignition coil circuits.
- Sensors: Engine coolant temperature sensor, mass air flow meter sub-assembly, air fuel ratio sensor.
- Other Systems: Immobiliser system, intake system (air leaks, throttle body condition), and VVT (Variable Valve Timing) system.
The guide provides detailed procedures for checking these components and systems, often referencing specific diagnostic steps and freeze frame data analysis.
