This time – thank you to an observant reader of my blog.
Note – there are no error messages regarding Lambda probes in the DME error message memory. Everything is as if it should be fine. Do you see anything suspicious?
As we see, the engine works in Stratified charge. Lambda in both banks 2.10 .. 2.20.
Readings of the control probes confirm the lean fuel mixture.
An incorrect parameter is marked in the image below:
Remark: Wideband probes are trimmed to compensate for the parameter difference from ideal for different electronic hubs and probes themselves. In a Homogeneous mixture, the trimming is done by using control probes (drifts of the probe management chipsets and DME MCU ADC Offset drifts are compensated, more info here). In Stratified charge, the differences in the “steepness” of the wideband probe curve Ip/Lambda are compensated by using reliable parameters: the amount of the used air, the torque developed by the engine, etc. Yes, this time, DME believes that it has managed to trim the wideband probe of the 1st bank (because there are no error messages recorded in its error message memory), but actually – the readings of the probe are entirely incorrect.
The correct voltage of the probe/Lambda:
a. 2.00/0.99 .. 1.01
b. 2.60/1.80 .. 2.20
c. 3.00/2.80 .. 3.50
d. 3.20/15.0 .. 16.0
If you see an incorrect reading of the Lambda probe in any of the injection modes/driving conditions, it has to be replaced immediately. Sooner or later, DME will notice the problem – it will not disappear. Instead, exactly in case of such a defect, you can expect a range of specific and difficult-to-explain problems, for example: large differences in Delay and/or Flowrate adaptations of the injectors between banks in Stratified charge mode; large Lambda differences between banks in Stratified charge mode; vibration (feeling of the diesel engine) exactly in Stratified charge mode.
