Flex fuel sensor

Post Reply
Westillo
Posts: 9
Joined: Tue Dec 29, 2020 11:45 am

Flex fuel sensor

Post by Westillo »

I wired a flex fuel sensor using switched 12v and chassis ground and signal to ecu i tried using both pins c13 and c32 with no luck. They wont read frequency. When i use a module that sends 0-5v it will read voltage but wiring direct to sensor it wont read. Is this something with firmware or am i missing something in the setup?
Thanks
stevieturbo
Posts: 1143
Joined: Sun Dec 07, 2008 2:04 pm

Re: Flex fuel sensor

Post by stevieturbo »

How do you have the input configured for fuel composition ?
Westillo
Posts: 9
Joined: Tue Dec 29, 2020 11:45 am

Re: Flex fuel sensor

Post by Westillo »

I set it up as thermistor
stevieturbo
Posts: 1143
Joined: Sun Dec 07, 2008 2:04 pm

Re: Flex fuel sensor

Post by stevieturbo »

Strange...seems to work fine on my S8 like that.

How are you determining it is not working ? Have you tried putting ethanol through it and seeing if the composition reading changes ?
TimH
JT Innovations
Posts: 710
Joined: Wed Sep 01, 2010 2:51 pm

Re: Flex fuel sensor

Post by TimH »

Set the input type to Bipolar. Only the AU types need to be set to thermistor. Found that out myself a few years ago even though it's counter-intuitive when the sensor "needs" a pullup enabled so you'd think thermistor for sure.
Westillo
Posts: 9
Joined: Tue Dec 29, 2020 11:45 am

Re: Flex fuel sensor

Post by Westillo »

I used the same pin and installed a module that plugs into the sensor and outputs 0-5v the ecu reads the voltage. But when i remove it and use it as its supposed to outputting frequency the ecu does not read content. I also have full tank of e85 so i know for sure there ethanol in the system but the ecu does not want to read the input frequency
stevieturbo
Posts: 1143
Joined: Sun Dec 07, 2008 2:04 pm

Re: Flex fuel sensor

Post by stevieturbo »

Are you sure it's wired correctly ?

Exactly what sensor is it ?

You also mention you used chassis ground....whilst it shouldn't really matter, isn't it normal to use sensor ground ?
Westillo
Posts: 9
Joined: Tue Dec 29, 2020 11:45 am

Re: Flex fuel sensor

Post by Westillo »

Ok so i did what tim said and its working now. The input type should be set to bipolar 5v. The syvecs youtube video got me confused
Post Reply