HEGO1 output = 2.5 volts, how to fix?

[1slickRED89]

I looked on the tweecer forum and here with no results. One of my O2s reads 2.5volts, when I swap the o2's it doesn't follow the sensor.

anyone ever have this before? If i don't fix it, any guess as to what will It do?

 

[SHOZ123]

So the 2.5V is on the one bank no matter which sensor is there? Sounds like a programming glitch with that bank stuck in closed loop.

 

[1slickRED89]

So the 2.5V is on the one bank no matter which sensor is there? Sounds like a programming glitch with that bank stuck in closed loop.

yeah that's right. I'm in the process of re-checking alot of my wiring (the MAF reads backwards too...???!!!???, figure that out). maybe I crossed a wire.

I initially thought it was tweecer related because both 'lamse' variables read out ok, and I think that they have something to do with how well the O2's are reading

 

[SHOZ123]

Seeing as the NBO2s are only a 0-1V output something is miss wired I would think.

 

[yamahaSHO]

Have you checked the O2 ground at the top of the block (valley of the block)?

 

[1slickRED89]

Installed a break out box today, the wiring is correct. I get a perfect switching signal from both O2's. I must have something setup wrong in the tweecer.

funny thing, the MAF behave perfectly, .6-.8 volts at idle and up from there, so why would it read backwards on my datalogs? I used the cookbook tweecer program for the L80MM???!!!???

 

[Axianator]

Corey,

Both of the problems you have noted (Left O2 readings pegged at a constant 2.5V and "backwards" MAF airflow readings) are known issues with the data file that CalCon uses to construct the D4U1 datalogging payload header. If you look closely, you will also find that CalCon incorrectly displays the KAMRF, injector pulsewidth and injector duty cycle values for bank 1. Rest assured that I am actively working to fix all of these datalogging registers for the next software release.

IOW, there is nothing wrong your factory HEGO sensors and/or the TwEECer module itself.

 

[1slickRED89]

Thanks, I do appreciate updates! does it compute the airflow backwards, or just display it backwards?

 

[Axianator]

Thanks, I do appreciate updates! does it compute the airflow backwards, or just display it backwards?

No problem!

The display problem is actually with the TwEECer software and not the EEC itself. Under normal circumstances, the EEC computes airflow based on the voltage it receives from the MAF sensor and then matches that voltage with the curve that it is programmed with.