Discussion and questions related to the course EFI Wiring Fundamentals
Came across an issue on the weekend where a Haltech Ti 150 psi sensor was reading 0.27v at 0Psi.
however the sensor voltage does increase as you apply pressure. (3bar was about 1.5V).
given these sensors are designed to read 0.5v at 0psi im starting to trouble shoot.
at the sensor im getting 5v between power and ground. i connected the plug to another known good sensor and the problem persisted.
i email haltech and their suggestion is to check the voltage at the ecu pin and ensure its 0.27v as the ecu sees it, this will either direct me to an ecu issue or a wiring issue.
has anyone else had experience in similar issues to this?
Is the sensor designed for a 5V supply or larger (like 10-30v?). Not all pressure sensors are 5V supply voltage.
they are definitely 5v sensors and have been working correctly for 2 years, one just suddenly started reading low..
I'd be testing that you do in fact have a regulated 5V supply and a solid sensor ground to the sensor. You should measure 5.00 volts across these two pins at the sensor connector. If this checks out and the signal wire has a sound connection to the ECU then I'd suggest it may be the sensor that's at fault. If you had another one you could swap in then that would prove the fault.
power and ground read 5.15v at the sensor which matches what the Haltech ecu is reading.
i do have a second sensor, when i swap it with the suspect sensor it ready 0.4v.
when i connect the suspect sensor with the Good sensors wiring it still reads 0.3v. this is the bit thats baffling me.
That's all a little weird to me. First up the sensor 5v is a regulated 5 volt so you should be seeing exactly 5.00 volts across those two terminals, not 5.15 volts. It's essential for this voltage to remain stable and fixed or the output from the sensor will wander around. It does sound like your sensor is suspect given that you're seeing a difference between the two sensors, however I'd expect you to be a little closer to 0.5 volts at rest with a good sensor.