Component Tests and General Diagnostics

2007 Toyota Highlander 4WD L4-2.4L (2AZ-FE)SECTION Component Tests and General Diagnostics
ECM Power Source Circuit

DESCRIPTION
When the ignition switch is turned to the ON position, battery voltage is applied to terminal IGSW of the ECM. The ECM "MREL" output signal causes current to flow to the coil, closing the EFI relay (marked: EFI) and supplying power to terminal +B of the ECM.

If the ignition switch is turned off, the ECM holds the EFI relay ON for a maximum of 2 seconds to allow for the initial setting of the throttle valve.

Wiring Diagram:






Step 1-3:




Step 4-6:




Step 7-8:




Step 9:




INSPECTION PROCEDURE
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.