Wideband problem

[DevInAz]

Hello,

My problem is when I try to calibrate my WB the gauge always reads .06% O2 value.

I've following this thread : http://www.vemssupport.com/forum/index.php/topic,1895.0.html but I don't have a battery calibration problem.

I've also done this page http://megasquirtavr.sourceforge.net/manual/Detailed.Sensor.Wide.html#Operate

All my wiring has been double and triple checked but my free air calibration reads the same.

I have 4.03v from GND to Pump -
Nernst to GND is 4.4v
Key and VEMS off - pump- to pump+ reads 0v       and with key on it reads .734v
pump- to nernst reads .365 at the highest VEMS setting of 200.    This voltage amount will not change no matter what numbers I put into the dc target value.

Hopefully someone has some recommendations.... i'm stuck. Thanks!

EDIT:   I'm using 2 100 ohm resistors for the pump readings. I've also verified my heater- with an LED. My heater works like it should.

[DevInAz]

Updated firmware to 1.1.97 then reloaded config file. Tried to calibrate WB but gauge still reads .06% O2.

I just double checked all my wiring with my grounds and found no problems.  I let auto calibrate stay on heating for 10 minutes and felt o2 and its hot but doesn't move.

I'm using Vemstune 11.15

[GintsK]

Pump+ pump- voltage must be closer to 0V (instead of 0.7V). It should be done before sensor connection.

Each time when you change those values VEMS needs to repower. Otherwise unit uses old values.

Check also widebend settings window for default values presence.

Gints

[DevInAz]

thanks GintsK! I'll go to the shop and try that in a little bit and update.

I've also started an error report in Vemstune but haven't had a reply with it. Did I do something wrong to not get a response?

[DevInAz]

Thanks GintsK for the advice. I measured the voltage and changed the pump pw little by little while turning the car off and on and saw it changing. The VEMS table recommends much higher numbers than the 3 that I ended up with. I now was able to get the o2 sensor to have all the correct voltages. I then plugged in the o2 and was able to get it to calibrate but it is now very jumpy and erractic. I started the car and recorded a log of it bouncing around. Is there anything I can do like change PID numbers to make it more stable?

This is also a brand new VEMS that was delivered last week with its spec sheet. Is it something I did to make these values so different than the factory in Hungary?

[GintsK]

If you are outside 97...105 for zero voltage, there are definitely something wrong. Do not connect sensor!

Normally changing zero value by one digit voltage changes output by aprox 0.3V.

So I would double check wiring, pinouts at both sides. Also for side-connections, short circuits. And if problem still persists you have an option to send unit back for inspection. But be careful with wiring otherwise sending to Hungary could be pointless!

Keep in mind they perform those tests at production. Successful at time.

Gints

[DevInAz]

Wiring for the wb is correct and checked again. I pulled the full harness for the WB out of the car and checked it for rubbing issues or burns but found nothing wrong. I ohmed the wires out to see if something was cross wired but it isn't.

I think I need to send this unit back to Hungary. I'll email them to see what they say.

Thanks again Gints!

[DevInAz]

The problem has been solved with a new board. It was under warranty and VEMS sent me a new one ASAP after supplying my readings to them.

I installed the new VEMS today and calibrated my o2 with no problems.

[Sprocket]

I had a similar problem, but since i had been seriously messing around with it, I ended up replacing the board too.

The question I keep asking myself is why the Vems Gauge uses the calibration resistor in the sensor connector, and Vems V3 doesn't, where the gauge doesn't need calibration, but the V3 does.

[gunni]

Because they wanted to save one analog channel instead of using it for the resistor measurement.