LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2015 >> IS 250 Base, RWD >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System (4GR-FSE) - Diagnostic Codes (5 Of 5) & Circuit Tests >> SFI System >> VC Output Circuit [04/2013 - 08/2015] >> Description
April 5, 2026: LEMON Manuals is launched! Read the announcement.

VC Output Circuit [04/2013 - 08/2015]: Description

The ECM constantly generates 5 V power source voltage from the battery voltages supplied to the +B (BATT) terminal to operate the microprocessor. The ECM also provides this power to the sensors through the VC output circuit.

Fig 1: VC Circuit Diagram
GTY456608Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

When the VC circuit is short-circuited, the microprocessor in the ECM and sensors that are supplied with power through the VC circuit are deactivated because the power is not supplied from the VC circuit. Under this condition, the system does not start up and the MIL does not illuminate even if the system malfunctions.

HINT: 

Under normal conditions, the MIL is illuminated when the engine switch is turned on (IG). The MIL goes off when the engine is started.