keebler65

i'm looking for info on the output of the IAT sensor on a OBD-0 hondas. i read somewhere it outputs 5v at one point, but i need some kind of voltage to temp cross-reference. does anyone have access to such info?

Joseph Davis

The ECU outputs 5 volt referrence to it, and reads the response across it. The IAT sensor itself is a thermistor; a resistor whose resistance changes with temperature.

Check your email; I'm linking you to a .pdf scan of one on my ftp.

keebler65

thanks for that! you have mail

BudaKai

Aren't they all (the sensors) 5v?

keebler65

well from my findings, its a thermistor hooked to ground. the otherside goes to the output to the ecu AND a resistor to +5v so its like a reference. what i needed was to know what the voltage-to-temp was at specific temps and to see if it was linear (which it isnt perfectly linear ). i'm thinking it will be easier to drill and tap my mani and insert a radioshack thermometer for less than $15. i dont want to have to keep a voltmeter on it and cross reference it everytime.

Joseph Davis

Ah, voltage divider circuit. The voltage the ECU sees back tells it the temp. Groovy... I know someone who was having a problem with this.