Wideband Calibration

yam · December 21, 2010, 06:34:15 AM

Hello,
Newbie vems user here. Got vems installed, and the car is running. However, I am unable to calibrate the wideband O2 sensor with vemstune. The sensor seems to be working properly, and I get plausible lambda values. When I go to the WB O2 calibration window, the value is always 0.5, regardless of the calibration value, and regardless of whether the O2 sensor is installed in the manifold, or out in "free-air". Thanks.

mattias · December 21, 2010, 11:20:11 AM

Study this page:
http://www.vems.hu/wiki/index.php?page=GenBoard%2FManual%2FWideBandHardwareTest

What version of VemsTune do you use?

I moved this thread to sensors, you obviously run a real VEMS ECU and not the wideband gauge.

yam · December 21, 2010, 11:24:37 PM

Thanks,
Problem was I was not patient enough in Vemstune.
I didn't wait long enough after pressing "Start Cal." to get the O2% reading. The WBO2 Calibration works fine.

quattroant · June 05, 2012, 08:27:37 PM

Thread revival... ;D

How long is an acceptable time to wait for vemstune to calibrate?

Using 1.1.81 I get 16.1% o2 and 1.1.96 I get the same reading using maximum 255 calibration figure.

Using 1.2.0 it reads constant ~27.50 afr when vemstune connects and when calibrating it says "heating..." But never moves to next step after 5mins, just afr flickers between ~10.50 afr and ~27.50.

O2 gauge does nothing in 1.2.0. Calibration doesn't progress.

Thanks in advance.

Kamuto · June 05, 2012, 11:19:13 PM

Quote from: quattroant on June 05, 2012, 08:27:37 PM
Thread revival... ;D

How long is an acceptable time to wait for vemstune to calibrate?

Using 1.1.81 I get 16.1% o2 and 1.1.96 I get the same reading using maximum 255 calibration figure.

Using 1.2.0 it reads constant ~27.50 afr when vemstune connects and when calibrating it says "heating..." But never moves to next step after 5mins, just afr flickers between ~10.50 afr and ~27.50.

O2 gauge does nothing in 1.2.0. Calibration doesn't progress.

Thanks in advance.

are you sure it's heating?

quattroant · June 07, 2012, 03:41:56 PM

I've got no idea...prob a good idea to follow the advice in that link above to test that then eh?
That'll teach me to skip through. :D

1.2.0 seems really screwy. You think it could be a wiring prob that doesn't show in earlier VT release somehow?
I just dont get why anything else south of 1.2.0 is at least giving believeable readings and maybe out of calibration and 1.2.0 is like it's gone insane with afr's bouncing all over. like ~27 I've only seen 18.91 afr highest on the other release's.

mattias · June 07, 2012, 04:12:00 PM

After starting calibration, wait 2-3 minutes, then if you can still touch the tip of the lambda sensor then the heater is not working - usually someone forgot to put the fuse in.

If the heater is not working you will not get a sane calibration value (too high) and have a hard time to reach the calibration target (too low).

fphil · June 08, 2012, 09:46:41 PM

Hurrah for the revival :D

QuoteHow long is an acceptable time to wait for vemstune to calibrate?

I met this one I think (see the thread). Everything could be stuck because the calibration value is far off. I dhanged the value until it wakes up as suggest by the forum (Mattias?)

quattroant · June 10, 2012, 04:01:59 PM

Ok, I have no 12v to the heater until the engine is physically started not just ign on.This would cause probs I guess as the ecu is expecting to run the heater while engine off but obviously never can whilst calibrating because the engine isn't running so gets stuck at the heating phase.

Can I just go ahead and hook up a fused 12v permanent live from the ecu main 12v live to pin 3?

If so I think my troubles are solved ;D

Joof · June 10, 2012, 04:54:17 PM

That's how mine is :)

quattroant · June 10, 2012, 06:22:38 PM

Looks like the existing 12v heater supply came spliced from 12v injector supply ->pin ec36/23 flyback. Why would this have been chosen.
Just a mistake or is there a reason you might use this? I'd ask the guy who made the adapter loom but sadly he passed away.

fphil · June 11, 2012, 09:28:30 AM

For the Vems there is no heater before the engine is running except if you put the genboard in debug mode by an mt command or if you start the VT calibration tool.
Round does start working with ignition on

mattias · June 11, 2012, 05:01:26 PM

Quote from: quattroant on June 10, 2012, 06:22:38 PM
Looks like the existing 12v heater supply came spliced from 12v injector supply ->pin ec36/23 flyback. Why would this have been chosen.
Just a mistake or is there a reason you might use this? I'd ask the guy who made the adapter loom but sadly he passed away.

Because that is how most stock Bosch harnesses work.

It's pretty simple though, you probably have a "misc output" that activates the main relay once the engine is running (rpm > 0, or something), so just invert that function (assign outputs dialog) while you're calibrating to force the harness to be powered up.

quattroant · July 16, 2012, 10:21:43 PM

Never updated this with my resolve.

Put a relayed permanent live to the wbo2 heater and used the ecu main 12v ignition on spliced as the switching wire.

Verified all the voltages from nernst, pump- and pump+

Works great now and managed to calibrate at a value of 198 finally giving me 20.9% :)

boostd audi · August 25, 2012, 05:57:04 AM

with wbo2 built in, 99% of all problems with it are wiring related.

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Wideband Calibration