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MembersPage/VasilisP/WideBandDiagnose (2015-09-03 18:37:24)

Wideband O2 related subpage of MembersPage/VasilisP

New ECU (v3/10581 AAN with NTC MAT input, oid 10875); config file uploaded as requested in the order comment (without any change: eg. not changed in any way; even the LSU4.9 was not changed, the paper provided with the order - or any LSU4.9 sensor sent out - instructs to check that 4.9 is configured)

Please note that [ECU with motronic55] can be ordered with "loom for LSU4.2" which is compatible with [LSU4.2] and very old fw. (but newer fw-s are better, and LSU4.9 also better, so the choice of most people). If you purchase LSU4.2 sensor, and write "please include small loom for AAN SSC5-LSU4.2" in the order comment, we'll include the loom for no extra charge: that allows to use new fw or reproduce the old setup (1.2.11 fw, config) with old fw which is not LSU4.9 certified.

  • When i say UPDATED i mean the VE tables which were last known to work. the HTA 12A config i asked you to use in order for the car to run propeply i expected you would have had the WBO2 4.9 checked, as the ECU comes with that WB sensor and not the old 4.2 which was in the config. I noticed that myself.
Sorry about that: indeed the config file was uploaded exactly as requested without any change; would have been kind to change config for LSU4.9 (ECUs are tested during manufacturing; packaging is separate step: the sensor, paper and small SSC5-LSU4.9 loom is included in the pack during packaging).

The 'update' was on VE and lamda tables that i had reviewed myself after recent checks.

Cool, thanks.

Before the engine starts with the key turned to the pre-ignition state, my rev meter jumps to above 2000rpm and my dash warning lights up the LOW OIL LEVEL. Both stay up unless i start the car.

I have only connected the WBO2 sensor and nothing more.

Injectors=... cc/min, type=... Fuel pressure= ... bar above MAP pressure

I noticed that all my map was too rich (ECU-s nowadays come with 1.2.31 fw, but in oid10875 order comment ancient 1.2.11 config was specified, and uploaded accordingly).

  • When i calibrated the WBO2 for the first time the 4.2 was selected, I calibrated the lamda sensor and used 214 number to achieve a 20.9 air calibration.

After changing the wide band setting to match the LSU4.9 sensor and tried to recalibrate, it went to 255 for me to have 20.1 at air.

Ahh OK, so actually very close. As a car owner, keep the 255 config value. (and if you really care, compensate for the over-sensitive LSU4.9 sensor with lambdatarget=0.89 where 0.88 intended; 1.00 where 1.00)

  • i am a car owner, and im afraid i have no means to measure what you ask. I can only tune the ECU.
  • OK. Although an Ohm measurement is the simplest thing that comes up during install (verifying injectors, igncoils, CLT/MAT sensors, WBO2 sensors, wires, all routine part of install+tune - even with a factory ECU if it comes to real-life diagnostic ). Anyway, glad to here you can tune the ECU, because that solves it all: you should be able to tune it as you wish.
  • do you have another sensor (LSU4.9 or LSU4.2)?
  • I have a 4.2 lamdda sensor lightly used. If i am to recalibrate should i clean it?
No, any attempt to clean the sensor could possibly damage it.
  • is it possible the sensor was dropped (eg. to concrete floor) ?
  • SENSOR WAS NOT DROPPED!!!!
lambdatarget (=lambda reading) desired lambda (real lambda)
LR LR, or LR-0.01 below 0.9
0.79 0.78
0.80 0.79
0.81 0.80
0.82 0.81
0.83 0.82
0.84 0.83
0.85 0.84
0.86 0.85
0.87 0.86
0.88 0.87
0.89 0.88
0.90 0.90
0.91 0.91
0.92 0.92
0.93 0.93
0.94 0.94
0.95 0.95
0.96 0.96
0.97 0.97
0.98 0.98
0.99 0.99
1.00 1.00
1.01 1.01

(some multiply with zzz constant and say "AFR" that is even more unnatural).

Unless any followup info, use that -0.01 under 0.9 lambda formula to compensate the miscalibration (255 instead of 258) for the sensor apparently living on the extreme (RCal) end of the Bosch-LSU4 calibration Gausscurve (being very sensitive, interestingly, so lower Ip current was needed at 20.9% O2.

Any air pressure, elevation, humidity data perhaps ? Would only be useful with Rcal Ohm data though)

  • it does not even prevent closed loop feedback EGO/lambda mixture control. VT can be configured to compensate, or another sensor can be used of course.

I am now using my old VEMS and i can send this unit back for all necessary checks.

It can be tuned where the engine is.

Maybe send the sensor if anything (but not before measuring Rcal).

I also tried 1.2.30 version without any success.

The key to success is measurements (even if just a few and simple in this case, they are important).

We suspect

If you publish the required (basic) measurements, and still not diagnosed the issue, then we'll send you LSU4.9 if necessary (a sensor that we might pre-test for you).

Besides the measurement, write the SSC5 pin number and the wire color for each pin (and the wire-color at the LSU4.9 sensor !), and verify connectivity and pin-correctness of the small SSC5-LSU4.9 loom according to the [LSU4.9 pdf].

Hello VasilisP,

To determine what is going on please provide a bit more information, please answer the following questions for me:

  • The first 4.9 lsu calibration (with the wrong selection on vemstune, 4.2 instead of 4.9) was done with a sensor completely new. The second calibration where the 255 was reached without being able to calibrate was done after the same 4.9 sensor was used with the car idling and myself looking at the trigger with a strobe light. So basically very little use.
  • My wiring is as sent from VEMS shop:
SSC5 1 WBO2 1 black

2 3 thick red

3 4 brown

4 5 blue

5 6 thin red

checked and verified

  • It does

Using the provided information i will provide hints on how to proceed.

Best regards, Dave

See FileArea (how to upload files). Generic instructions on MembersPage

I dont have vemslog with the heating cycle but i can make one. Thx.