Need power steering/cooling solenoid test

1996 LEXUS ES 300

180,000 MILES • 3.0L • 6 CYL • 2WD • AUTOMATIC

PHIL TREECE

MEMBER
1 POST

Overheating on short distances and on idle. Coolant reservoir boiling. Changed thermostat and flushed the system. Trying to get the cooling fan to move faster so the engine can cool down. Also I was wondering if I can adjust the set screw at the end of the solenoid to get more pressure into the fan.

Thanks for the time,
Phil Treece

May 3, 2021 at 1:27 AM

JACOBANDNICKOLAS

✓Experienced Mechanic
110,240 POSTS

Hi Phil,

The fan speed is controlled by the cooling fan ECU. It is not adjustable. Here is how it all works:

The Cooling Fan ECU receives various signals, i.e, the engine RPM signal from the Ignitor, engine idle speed signal from the Throttle Position Sensor, Coolant Temperature signal from the Engine Coolant Temperature Sensor (Water Temperature Sensor), A/C Refrigerant Pressure Signal from A/C Pressure SW.

The Cooling fan ECU judges the Engine temperature based on the above-mentioned signals drives the Solenoid Valve and controls the speed of the Cooling Fan.

Do you hear the fan speed increase as the engine temp increases?

I attached the diagnostics for the cooling fan ECU in the pics below. Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-wiring

The last pic below shows the location of the cooling fan ECU.

I hope this helps. Let me know if you have other questions.

Take care,

Joe

See pics below.

Images (Click to enlarge)

Professional Diagram for 2CarPros Members
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May 3, 2021 at 12:26 PM

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