DTC P1604: Startability Malfunction [03/2019 - 09/2022]: Description

WARNING: This page is about a different car, the 2022 Toyota Corolla, 2021 Toyota Corolla, 2020 Toyota Corolla, and 2019 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.

This DTC is stored when the engine does not start even though the STA signal is input or when the engine takes a long time to start, and when the engine speed is low or the engine stalls just after the engine starts.

Using the Techstream, the conditions present when the DTC was stored can be confirmed by referring to the Freeze Frame Data. Freeze frame data records engine conditions when a malfunction occurs. This information can be useful when troubleshooting.

It is necessary to check if the vehicle ran out of fuel before performing troubleshooting, as this DTC is also stored when there is engine starting trouble due to running out of fuel.

DTC No.	Detection Item	DTC Detection Condition	MIL	Memory	Note
P1604	Startability Malfunction	Either of the following conditions is met: (1 trip detection logic): The engine speed is below 500 rpm with the STA signal on for a certain amount of time (refer to the illustration below). After the engine starts (engine speed is 500 rpm or more), the engine speed drops to 200 rpm or less within approximately 2 seconds.	Does not come on	DTC stored	DTC for Mexico Models - Applies

Trouble Area
Ignition system	Spark plug Ignition coil assembly
Fuel system	Fuel injector assembly Fuel pump Fuel pump control circuit Fuel pressure regulator assembly Fuel line Purge VSV system Fuel quality (existence of foreign matter, degradation)
Intake and exhaust systems	Mass air flow meter sub-assembly Intake system (Air leaks or deposit accumulation) Throttle body assembly Air fuel ratio sensor Heated oxygen sensor Camshaft timing oil control valve assembly VVT system (Variable Valve Timing system)
Other control systems	ECM Wire harness or connector Knock sensor Engine coolant temperature sensor
Engine	Thermostat Engine assembly
High load from another system	Air conditioning system Power steering system Electrical load signal system CVT system