Issue with flex fuel

s300 and SManager software questions & answers
Post Reply
DierwulfBL
Posts: 8
Joined: Tue Jun 04, 2019 7:12 pm

Issue with flex fuel

Post by DierwulfBL » Tue Jun 04, 2019 8:10 pm

Good day all,

Recently went flex fuel on my s300 H2B setup. Was running great on e85 but did a track day with only 93 available and the car ran richer and richer the more 93 fill ups were done. Come to find out the sensor is reading 85% ethanol when it should be reading E10 or so. I tried another ethanol sensor to no effect, and fixed a possible loose ground for the sensor. Tuner said it was reading 66% on ethanol when it was tuned so it was working at some point I think. What could be the cause of it being stuck at e85 reading? I tried reflashing the map in case it was corrupted somehow and this did not work. Ethanol sensor is pinned to D10 and the tune is calibrated to get the data off D10 as well. I think its v4 hardware, Any help would be appreciated.

User avatar
Spunkster
Site Admin
Posts: 17658
Joined: Fri Sep 20, 2002 5:06 pm
Location: Hondata
Contact:

Re: Issue with flex fuel

Post by Spunkster » Wed Jun 05, 2019 9:19 am

What is the serial number that is on the s300 board inside the ECU?

DierwulfBL
Posts: 8
Joined: Tue Jun 04, 2019 7:12 pm

Re: Issue with flex fuel

Post by DierwulfBL » Wed Jun 05, 2019 4:30 pm

Serial number is "S300-6362" and its a green board so it must be a v3 not v4.

User avatar
Spunkster
Site Admin
Posts: 17658
Joined: Fri Sep 20, 2002 5:06 pm
Location: Hondata
Contact:

Re: Issue with flex fuel

Post by Spunkster » Wed Jun 05, 2019 4:49 pm

What flex fuel analyzer are you using?

You have a version 1 s300.

DierwulfBL
Posts: 8
Joined: Tue Jun 04, 2019 7:12 pm

Re: Issue with flex fuel

Post by DierwulfBL » Wed Jun 05, 2019 5:26 pm

Smanager says the hardware is v3, and its running Coil On Plug from hondata without issue and has bluetooth capability. I am using the Hondata recommended sensor.

DierwulfBL
Posts: 8
Joined: Tue Jun 04, 2019 7:12 pm

Re: Issue with flex fuel

Post by DierwulfBL » Wed Jun 05, 2019 5:52 pm

I must have been looking at the firmware version. It's definitely a v1, although I have zero clue how it's running the CPR kit on a v1 as that supposedly is not supported

DierwulfBL
Posts: 8
Joined: Tue Jun 04, 2019 7:12 pm

Re: Issue with flex fuel

Post by DierwulfBL » Wed Jun 05, 2019 7:31 pm

The recommended sensor that I am using is GM 13577429 by the way. It looks like v1 may support CPR and Flex Fuel as well possibly (I swear i read somewhere both were not supported until v3, but could be very wrong)? I am not sure if there is a resistor anywhere and the instructions are confusing on how to wire that up, could this be the cause?

crluver123
Posts: 111
Joined: Tue Oct 10, 2006 10:13 pm

Re: Issue with flex fuel

Post by crluver123 » Wed Jun 05, 2019 7:51 pm

the v1 board only supports flex fuel sensors if you use an ethanol content analyzer. It essentially is a converter that reads the flex fuel sensor signals and converts them to analog signals that the v1 board can recognize. You can not wire a flex fuel sensor directly to a v1 board.

If you have the flex fuel sensor wired directly to the ecu, yes that will definitely be a problem

DierwulfBL
Posts: 8
Joined: Tue Jun 04, 2019 7:12 pm

Re: Issue with flex fuel

Post by DierwulfBL » Thu Jun 06, 2019 5:10 am

Does anyone make an ECA that has no gauge and doesnt cost $150? Also, is the D10 pin the analog input 0? There seems to be information on hondatas site about analog inputs 1 and 2 but not 0. I am wondering if i plug in a v3 into my current setup if its going to work or be back at square one. I have zero desire to know what the ethanol % is, if I care enough i can look in Smanager. Does the v3 also require the resistor? Is there a wiring diagram for how to hook the resistor up, like can I just shove it up into the harness plug (back probed) on the sensor side or do i have to solder wires on both ends of the resistor and bridge the power and signal wires with it? Is the resistor still needed with an ECA setup?

User avatar
Spunkster
Site Admin
Posts: 17658
Joined: Fri Sep 20, 2002 5:06 pm
Location: Hondata
Contact:

Re: Issue with flex fuel

Post by Spunkster » Thu Jun 06, 2019 10:10 am

The input you are using will work if you use a ethanol content analyzer. IT will not work without the extra hardware.

DierwulfBL
Posts: 8
Joined: Tue Jun 04, 2019 7:12 pm

Re: Issue with flex fuel

Post by DierwulfBL » Thu Jun 06, 2019 10:49 am

Does anyone sell an "ECA" that is just a board that takes a PWM signal and converts it to 0-5v without a gauge?

Also, if I purchase a s300v3, will I still need the ECA?

What is the deal with the resistor?

User avatar
Spunkster
Site Admin
Posts: 17658
Joined: Fri Sep 20, 2002 5:06 pm
Location: Hondata
Contact:

Re: Issue with flex fuel

Post by Spunkster » Thu Jun 06, 2019 10:57 am

If you upgrade to the V3 you can use just the sensor. The instructions in the help file must be followed for it to work. Without the resistor it will not work.

DierwulfBL
Posts: 8
Joined: Tue Jun 04, 2019 7:12 pm

Re: Issue with flex fuel

Post by DierwulfBL » Thu Jun 06, 2019 11:13 am

Can I backprobe the resistor into the sensor plug to bridge VCC and Signal on the sensor? or will I need to bridge the 2 wires with the resister soldered to 2 wires with each wire hooked into the harness wires where they terminate? Or does the resistor go in-line with the signal wire?

User avatar
Spunkster
Site Admin
Posts: 17658
Joined: Fri Sep 20, 2002 5:06 pm
Location: Hondata
Contact:

Re: Issue with flex fuel

Post by Spunkster » Thu Jun 06, 2019 12:09 pm

A 2.4 k ohm resistor needs to be wired between Out and Vcc. You can do this anywhere in the wiring between the ECU and sensor. Do not connect Out and Vcc together; one end of the resistor is wired to Vcc and the other end to Out.

Post Reply