DTC P1644-9E: Starter Circuit Stuck On [11/2016 - ]: Description

WARNING: This page is about a different car, the 2019 Toyota Highlander, 2018 Toyota Highlander, and 2017 Toyota Highlander. However, it is still accessible from the selected car via links, so may be relevant.

The engine stop and start ECU detects abnormalities in the DI (+B) value that is input from the integrated IC (stop and start backup boost converter integrated IC) to the CPU.

If a logical inconsistency occurs between the +B value and DI (+B) value input to the CPU, the engine stop and start ECU stores DTC P16449E and blinks the stop and start cancel indicator.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Memory	Note
P16449E	Starter Circuit Stuck On	Both of the following conditions are met for 1 second or more (1 trip detection logic): +B terminal voltage is 9.16 V or more. Low battery voltage is detected.	Wire harness or connector Engine stop and start ECU	Blinks	DTC stored	SAE Code: P1644