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Wideband not heating correctly (SOLVED)

Started by scottish-sr, May 28, 2014, 04:00:31 PM

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scottish-sr

Hi all.
I'm having problems with my wideband not registering a reading.
The engine is an SR20DET and I purchased it as a drop in running engine using VEMS.

I initially thought the wideband sensor was to blame as there was 12v going to connection, so I bought a new sensor but it's doing the same.

When doing WB02 calibration it just stays on the heating phase. The sensor gets slightly warm.

All the wiring looks intact from inspection.
The car starts, runs and all other sensors are registering.

Its Vems 3.3
Any ideas?

VEMS

Hello Scottish-SR,

Here is a quick step plan to check your Wideband hardware and setup:

1) Do the entered ecu calibrations for Pump zero pw and Pump PID nernst target match your supplied ecu calibration paper ? Check and adjust if needed
2) Is the Wideband plug properly connected to the v3 unit? Verify wiring from ec18 plug to wideband connector with DVM for proper connection and wire resistance.
3) Verify is fused VBATT is present at wideband connector pin#3
4) Measure Rcal resistance (between sensor pin 2 and 6) lookup the base calibration value on: http://www.vems.hu/wiki/index.php?page=GenBoard/Manual/Config/WidebandCalibration and enter this as a base calibration value before next step.
5) Are you performing the wideband calibration with the sensor out of exhaust in free air ? If not so, please redo the calibration in free air.
6) If you get to this step everything in external setup seems good, we verify ecu internal operation. Follow procedure on: http://www.vems.hu/wiki/index.php?page=GenBoard/Manual/WideBandHardwareTest
7) If the ecu passes internal operation testing there must be some connection problem, recheck wiring and make sure.

Please report back with your findings so we can get to the bottom of this,

Best regards, Dave



scottish-sr

Hi,

Thanks for the reply.

I purchased the engine complete with Vems second hand so there was no calibration certificate with it. I know Rob and also Gunni are familiar with the engine as they were involved in the mapping.

The wiring all looks intact complete with 3A fuse on the power cable. This fuse was initially not fitted when I received the ECU but is in place now.

The calibration is being done with the exhaust in free air.

The values between GRND/Pump- was 4.1v, GRND/Nernst, 3.8v and between PIN1/PIN5 +450mv.

All other sensors are reading and functioning correctly. I seem to recall reading that a certain type of USB/Serial cable has to be used, is this correct?

I've attached screenshots of the readings on VEMS.



Sprocket

Wiki brings this up

[1.2.4] - was experimental, now obsolete, WILL NOT BE RELEASED

wideband change: comes up faster if ECU powered down only for a second and sensor is still very warm. Not all sensors behave same under these conditions and this might not always work as expected (remember, if wbo2 does not measure sensor is likely to get clogged so revert ASAP if experiencing that), so we're collecting experience and will apply improvements


scottish-sr

Fingers crossed it's a firmware problem then. Ive downloaded the latest Vems dated 29/5/14 and the firmware updates and installed them. Just need to update them to the ECU.
Do I need to back the mapping settings, ECU calibrations up before uploading the firmware, or will these remain the same?

scottish-sr

Also, do I need to upload all firmware released as 'ok' which are 1.2.11 & 1.2.16 from the current 1.2.4? Or will the latest one do? I see 1.2.23 is still 'testing'

scottish-sr

#6
Thanks to Sprocket. I updated the firmware to 1.2.11 and the wideband started reading.
I tried it with the used sensor and it was 223 for calibration and then the new sensor which was 163. I left the new sensor fitted.