Hi Guys, I baffled, I added an oil temp and an oil pressure sensor to my NB and I was able to get the pressure sensor working fine but can't get the temp sensor to work. Here's the details

ECU = MS3 PNP from DITAutotune 1.5.1
Temp Sensor = GM Coolant sensor. Yellow wire connected to Analog In 2, black wire connected to Sensor Ground on ECU
TunerStudio= TS Ultra 3.1.04a
Tune attached

Temps shows 70 with engine running 0 with engine off.

Thanks for the help

 

You must add a pullup resistor to a thermistor input. Typically 2.7K to 5V. With no pullup the ADC input is shorted to ground through the thermistor, so it always reads zero.

Tunerstudio overwrites the first and last ADC values with an error value that's usually right in the middle of the temperature reading range when you make a temperature calibration curve. I don't know why you'd want a failure mode like that, but it's what it does. I am assuming 70 is celcius, which is nearish the 180F it defaults to IIRC.

 

Thanks for a quick reply. So I need to connect the 5v reference wire to the signal wire through a 2.7k resister.