Author Topic: Water Temperature Sensor specification needed to setup MegaSquirt  (Read 4736 times)

RuthlessPerformance

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Does anyone know where I can find the specifications for the stock water temperature sensor for the factory ECU on a 93 M42 motor, I believe the Bosch Part # is 12621747281. The information I'm looking for are the three Ohm points with corresponding Degree figures.

Example (GM Sensor):

Temperature   Ohms
48 degrees F   7000
87 degrees F   1930
146 degrees F   560

Any help would be greatly appreciated.

Joey
Joey

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DesktopDave

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Re: Water Temperature Sensor specification needed to setup MegaSquirt
« Reply #1 on: May 20, 2014, 03:49:48 PM »
Pull the sensor, chill/heat as necessary & measure values? You only need three data points, right? I found this page out on the interwebs with the M20 values:

Quote
    Calibrate your CLT Sensor and IAT Sensor.

        Again from TunerStudio, click 'Tools > Calibrate Thermistor Tables'.  Make sure 'Coolant Temperature Sensor' is selected at the top.

            For the CLT, use the following table with a bias resistor setting of 2490 ohms:
            Temperature    F / C    Resistance In Ohms
            14 / -10    9500
            68 / 20    2500
            176 / 80    330

        Enter these values, and click 'Write to Controller'.

        Now you'll do the same for the IAT.  Select 'Intake Temperature Sensor' at the top in the drop down box.  (NOTE - If you are removing your MAF/AFM as a part of the DIYPNP installation process, do not recalibrate your IAT Sensor now)

            For the IAT, use the following table with a bias resistor setting of 2490 ohms:
            Temperature    F / C    Resistance In Ohms
            14 / -10    9500
            68 / 20    2500
            176 / 80    330

        Enter these values, and click 'Write to Controller'.  Now click Close to Exit.

    Finally, you should calibrate your O2 Sensor to the ECU.  To do this, click 'Tools > Calibrate AFR Table'.

        Choose your O2 Sensor from the list.  Choose Narrowband for the stock O2 Sensor.  Or select your wideband and the proper configuration of said wideband from the drop-down list.

        Click 'Write to Controller'.  Once finished writing, click 'Close'.
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