AEM oil temp sensor not correlating with motec

[Trigsby]

Hello so I purchased a AEM 30-2012 temp sensor and set it up on motec with the data from aem. The voltage the ecu is getting is listing the temp to be about 20 colder than it is. When I check the sensor against resistance and the chart it’s spot on with the temp. Any ideas what would cause the voltage to be reading the temperature to be higher? Thanks.

[Stephen Dean]

Having a look at the supplied data on the AEM website, they have used a 2.2k ohm pullup for the voltage supply, where as the M1 uses a 1k ohm to 5V pullup. This will skew the voltage values produced by the sensor.

Try the numbers in the attached spreadsheet for this sensor.

[David Ferguson]

I know it's probably a typo, but if not -- what MoTeC M1 inputs have a 5k ohm pullup?

The M1 Hardware Tech Note indicates the Temp inputs have a 1k ohm pullup to 5V.

The spreadsheet doesn't mention what the measured input conditions were (ie. pullup value and voltage).

[Stephen Dean]

Hi Dave,

You are correct on that one, I fat fingered it heading out the door on Friday afternoon.

I've edited the post to show the correct information. It was supposed to be 1k ohm to 5v pullup.

The Temp sensors are tested in our climate test chamber using the AT inputs (so 1K to 5V) on a C185 Display.