G4+ DI verifications

[Anfurnyy]

Planning on using flex fuel in my PNP Grv4 G4+ and i recently found out the ethanol sensor is required to be wired into a DI not an Analog input that it already is. 

I also read that the Clutch switch needs to be wired into a DI also in order to use Launch Control

Are both of these true and does this ECU use the clutch switch? I couldnt find anything for it as an input or pinout in the Pinouts in the content section in PC link but i just wanted to check to make sure so im not swapping stuff out for no reason. 

 

Thanks!

[DerekAE86]

Flex fuel sensor has to be wired to a digital input yes. Because they provide both ethanol content and fuel temp readings in 1 signal.

They do this by varying the frequency (how fast they switch the digital signal on and off) and pulse width (how long it stays active during that switch).
Make sure it's wired to 12v and Chassis Ground too. They don't work from 5v and Sensor Ground.

You technically can wire a basic on/off switch (like the clutch switch) to an analog input if don't have any free digital inputs.
You might have to use an external pull-up resistor depending on the polarity of the signal and how the clutch is wired.

Would need to know exactly before giving detailed advise. So wiring the clutch to a digital input is just easier if you don't know or aren't confident.

[Anfurnyy]

6 minutes ago, DerekAE86 said:

Flex fuel sensor has to be wired to a digital input yes. Because they provide both ethanol content and fuel temp readings in 1 signal.

They do this by varying the frequency (how fast they switch the digital signal on and off) and pulse width (how long it stays active during that switch).
Make sure it's wired to 12v and Chassis Ground too. They don't work from 5v and Sensor Ground.

You technically can wire a basic on/off switch (like the clutch switch) to an analog input if don't have any free digital inputs.
You might have to use an external pull-up resistor depending on the polarity of the signal and how the clutch is wired.

Would need to know exactly before giving detailed advise. So wiring the clutch to a digital input is just easier if you don't know or aren't confident.

Oh I guess I didn't know they provide temp as well. It's just a GM ethanol sensor not a link brand sensor so I'm not sure if that still holds true?

It is wired into 12v. Its utilizing a speed density conversion harness from the MAF harness, for power ground and input to the ECU. 

I'll just wire it Into a DI, just seemed a bit more simple. 

[koracing]

I've not successfully received good fuel temperature data off of a flex fuel sensor so I'm not sure how well that works on the Link.  You'll need to enable the pullup resistor on the input for most flex fuel sensors also but should work fine otherwise if it is an OEM type Continental sensor.  

[Adamw]

45 minutes ago, koracing said:

I've not successfully received good fuel temperature data off of a flex fuel sensor so I'm not sure how well that works on the Link.

Of course it works, it has to otherwise modelled fuel equation wouldnt work.  If G4X make sure you use the correct active edge (rising for the link sensor and most others I know of).  

Random G4+ log:

G4X:

[koracing]

29 minutes ago, Adamw said:

If G4X make sure you use the correct active edge (rising for the link sensor and most others I know of).

In the Help menu for G4X it says there are three types of sensors: Link, Siemens, and Continental.  For the Continental and Siemens it says to set the active edge to falling and for the Link sensor it says to set to rising.  So how would I interpret the help menu directions differently?

 

[Adamw]

I havent personally ever used a seimens one or the wide body continental one, all have been the narrow ones similar to the link branded one.  If you arent using a Link sensor then you will have to verify yourself.  Just try it either way, the temp will read correct one way and miles off the other.   

[DerekAE86]

I use a narrow Continental one and it works for fuel temp. Can't vouch for it's accuracy but it appears to report believable temps.

[koracing]

29 minutes ago, Adamw said:

I havent personally ever used a seimens one or the wide body continental one, all have been the narrow ones similar to the link branded one.  If you arent using a Link sensor then you will have to verify yourself.  Just try it either way, the temp will read correct one way and miles off the other.   

My mistake. Will try the other setting going forward and on current vehicles I'm tuning and see how it plays.  Previous versions of Link and other branded ecus I used in the past with the Siemens and wide body Continental sensors (13577379) didn't have this active edge setting to deal with.  I feel the help menu is arguably ambiguous as to the proper settings for current commonly available sensors.  Other information on ethanol sensors in the help menu appears to be dated as well given the instructions say to set the sensor type to "GM Siemens Ethanol Sensor" - which isn't a setting you can do in either the G4+ or the G4x. Also, for some reason, I assumed the Link sensor was different than other commonly used "narrow" Continental ethanol sensors (13577429) simply based on the price, lol.

I would like to request that the help menu instructions be modified in a future release to possibly clarify the discrepancy in sensor types with Continental sensor settings to reflect currently available products as I feel like I can't be the only one to have made this mistake.  Is this a possibility?