I have installed an oil pressure sensor switch on my Abarth 595, have wired it according to the pin out for the sensor, Ground, 5v & Sensor signal, however the voltage is reading a constant 4.95volts. I am using B4 (analog in #2). Can anyone shed any information please? I am using an abarth Plug and play for the harness. Also the switch was previously programmed to read low oil pressure when the engine is off. So the signal wire was actually working thanks.
Check you don’t have a pull up configured. Otherwise disconnect the analogue in pin from the ecu and measure the voltage using a voltmeter
sorted thanks, it was a loose wire connection at the plug.
Hello can you please explain why I should do a pulldown on the resistor?
Pulldown is connected between the sensor signal line and the ground (0V). This pulls the signal line to 0V when the sensor output voltage is low. This prevents input “floating”.
If you use “pullup” with analog sensor, voltage it sees is always +5V regardless what sensor output voltage is.
- With 0-5V output sensors, “pulldown” must be used.
- Passive sensors that have variable resistance (ie. temperature sensors) needs always “pullup” resistor. (think it as voltage divider).
Thank you for the explanation, however on my setup regardless of the pullup or pulldown I still get the same voltage reading.