DTC P1604: Startability Malfunction [08/2013 - ]: Description

WARNING: This page is about a different car, the 2014 Lexus ES 300h. However, it is still accessible from the selected car via links, so may be relevant.

If the engine does not start or it takes a long time for the engine to start although the ECM is receiving the engine start request signal from the power management control ECU via CAN communication, this DTC will be stored.

Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

It is necessary to check if the vehicle has run out of fuel before starting diagnosis because this DTC is also stored due to running out of fuel.

DTC No.	DTC Detection Condition
P1604	Either of the conditions is met (1 trip detection logic): The engine speed is less than 500 rpm with the engine start 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

Fig 1: Starting Time To Engine Coolant Temperature Chart