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.
1996 Lexus ES 300FACTORY OEM SERVICE PROCEDURE
A/C Cut Control System
CAUTION:
If ECM replacement is instructed, always ensure ECM harness connector and ground circuit are okay. If either are suspect, repair as necessary and repeat testing to confirm ECM malfunction.
- Access ECM connectors behind glove box. Turn ignition on. Leave harness connectors attached to ECM. Backprobing connector, measure voltage between chassis ground and terminal No. 5 (Light Green/Red wire) at ECM E10 connector. See Figure. With A/C on, battery voltage should be present. With A/C off, 0-2 volts should be present.
- If voltage is as specified, replace ECM and retest. If voltage is not as specified, check for open or short in circuit between ECM andA/C control assembly. See appropriate wiring diagram in WIRING DIAGRAMS article. If circuit is okay, replace A/C control assembly.
Factory Service Tools
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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.