DTC P1542-00: Stop and Start Cranking Time Too Long [03/2023 - ]: Description

WARNING: This page is about a different car, the 2025 Lexus NX 250, 2024 Lexus NX 250, 2023 Lexus NX 250, and 2022 Lexus NX 250. However, it is still accessible from the selected car via links, so may be relevant.

When the engine is being restarted by the stop and start system, if the engine does not start and the start time is long despite the input of the STA signal, a DTC is stored.

DTC No.	Detection Item	DTC Detection Condition	MIL	Note
P1542-00	Stop and Start Cranking Time Too Long	When the engine is being restarted by the stop and start system, it is detected that the engine speed is less than 400 rpm for 1.38 seconds or more (the start time is too long or the engine has not started) 2 times (2 trip detection logic).	Comes on	SAE Code: P1542 DTC for Mexico Models: Does not apply

Trouble Area
Starter system	Battery depletion Starter malfunction Starter circuit
Engine	Engine assembly
Ignition system	Spark plug Ignition coil assembly
Fuel system	Direct fuel injector assembly Port fuel injector assembly Fuel pump (for high pressure side) Fuel pump (for low pressure side) Fuel pump control circuit Fuel suction plate sub-assembly Fuel main valve assembly Fuel line Purge VSV system Fuel quality (existence of foreign matter, degradation)
Intake and exhaust systems	EGR system Mass air flow meter sub-assembly Intake system (Air leaks or deposit accumulation) Throttle body with motor assembly Air fuel ratio sensor (sensor 1) Air fuel ratio sensor (sensor 2) Cam timing control motor with EDU assembly Cam timing oil control solenoid assembly Variable Valve Timing system (VVT-iE, VVT-i system)
Other control systems	ECM Wire harness or connector Knock control sensor Engine coolant temperature sensor Immobiliser system
Engine	Water inlet with thermostat sub-assembly Engine assembly Crankshaft position sensor malfunction
High load from another system	Air conditioning system Power steering system Electrical load signal system A/T system