Calibrating wbo2 problem

B3mt1 · February 25, 2013, 12:38:14 PM

Hi, I have problem with calibrating wbo2 sensor. During calibration sensor gets hot and starts to calibrate then gets to 255 but obviously sensor isn't calibrated as you can see on the picture. I have two sensors and it is same thing for other one. Firmware is 1.1.96 and vems tune is latest stable.

GintsK · February 25, 2013, 02:15:16 PM

Does the sensor heating works? Sensor getting warm?

B3mt1 · February 25, 2013, 03:02:53 PM

Quote from: GintsK on February 25, 2013, 02:15:16 PM
Does the sensor heating works? Sensor getting warm?

yes, both of them

GintsK · February 25, 2013, 08:24:31 PM

Then you have to check wiring. And WBO2 related settings including pump zero and nernst target.
New unit? What sensor?

B3mt1 · February 26, 2013, 09:12:02 AM

Wiring is ok I have checked it recently and it is vems harness. WBO2 settings are default. One sensor is slightly used other one is old three years, both are bosch lsu4 from vems shop.

GintsK · February 26, 2013, 11:01:57 AM

How the problem starts?

There is no defaults for pump zero and nernst target.

B3mt1 · February 26, 2013, 08:27:54 PM

I don't understand question, if you mean when problem started I can't tell you with certainty because a lot of parameters and firmwares changed during two calibrations.
Pump zero is 101 and nernst target is 136.

Sensor resistance is 142 ohm, what is normal ?

GintsK · February 26, 2013, 08:56:06 PM

Heater resistance should be 3...6 Ohm.

jrussell · February 27, 2013, 05:54:11 AM

This is the best and most clear guide I know of to verify your hardware in relation to the wideband controller.
http://www.vems.hu/wiki/index.php?page=GenBoard%2FManual%2FWideBandHardwareTest

B3mt1 · February 27, 2013, 10:56:18 AM

Quote from: GintsK on February 26, 2013, 08:56:06 PM
Heater resistance should be 3...6 Ohm.

i meant a resistance between pin 2 and pin 6

Quote from: jrussell on February 27, 2013, 05:54:11 AM
This is the best and most clear guide I know of to verify your hardware in relation to the wideband controller.
http://www.vems.hu/wiki/index.php?page=GenBoard%2FManual%2FWideBandHardwareTest

ok, i am gonna try it

GintsK · February 27, 2013, 06:36:51 PM

Quote from: B3mt1 on February 27, 2013, 10:56:18 AM
Quote from: GintsK on February 26, 2013, 08:56:06 PM
Heater resistance should be 3...6 Ohm.
i meant a resistance between pin 2 and pin 6

It is BOSCH factory calibration resistor. Pin 2 is not used in VEMS V3.

B3mt1 · April 05, 2013, 07:28:16 PM

DVM -   DVM +   My values   Var to Change   Notes
GND   pump-   +4.04V       Just verify
pump-   pump+   0mV   pump_pw_zero   WBO2 off
pump-   nernst   +250mV   wbo2_nernst_dc_target   WBO2 on

When I lower nernst dc target to 80, value is around 120mV, when i raise nernst target voltage between pump- and nernst won't get over 250mV. Did it everything by instructions, only i didn't connect anything to heater.

B3mt1 · April 09, 2013, 05:13:36 PM

Solved the problem :D
Oxidised contact on nernst pin inside vems.

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Calibrating wbo2 problem