Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1990 Toyota Corolla Base, AutomaticFACTORY OEM SERVICE PROCEDURE
Electronic Control Unit (Ecu)
- Obtain access to ECU. See Figure. Turn ignition on. Using voltmeter, check voltage between designated terminals on ECU with connector installed on ECU. Voltage should be as specified. See Fig 1 and Fig 2.
- Turn ignition off. Using ohmmeter, check for continuity between specified terminals. Continuity should be as specified. See Fig 1 and Fig 2.
NOTE:
Connector "A" goes to shift lock solenoid. Connector "B" goes
to ignition switch and brakelight switch. Connector "C" goes to shift lock
control switch.
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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