Code Definition

P1604 — Startability Malfunction

System: Powertrain  |  Type: Manufacturer-Specific  |  Make: Toyota

About P1604

P1604 is a manufacturer-specific powertrain diagnostic trouble code recorded for Toyota vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

P1604 is a manufacturer-specific code. The same code string on a different make may have a different meaning. Always confirm the code's definition against the vehicle's service information for the specific make and model under test.

Code Information

The powertrain control module (PCM) sets P1604 when it detects difficulty in starting the engine, such as extended cranking time, failure to start, or repeated start attempts. The PCM monitors engine speed (RPM), crankshaft position sensor (CKP) signals, fuel system performance, and ignition timing during startup. If the starting parameters deviate from expected values, the fault is logged.

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