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  • #16
    Originally posted by Acki View Post
    During coast down I have sometimes rich mixture short before the fuel cut kicks in and this caused the DTC sometimes - I modified the DTC limit (VSRMX I think was it) a little bit and not DTC again.
    If everything is set correct there are no reasons for DTC.

    IIRC there is no direct connections in logics between five’s VSR values and DTC codes. VSR are voltage levels of lambda sensor input signal, but DTC codes are result from correction/calculation values by lambda adaptation procedure. First is captured value by ADC and this is only indicator for state of exhaust gases. Not used like values any more. Second are calculated/recalculated values by complex procedures. These values are based on initial middle value 80 hex +/- result of few subroutines with cut/delay timers, 3 maps and couple recalculations. Through these timers and maps, the developer has made a logic that reflects the changes from the ADC, both from lean to the rich and the reverse, as well as the transient processes occurring when working with the throttle and go from/to idle state.

    All that logic is optimized for stock narrowband sensor. If you sometime log data from ADC for stock narrowband and simulated narrowband sensors, will find differences in their reactions for which Dimitri wrote above.

    Simulated narrowband sensors follow the “logics” of wideband O2 sensor and change signal somehow “slowly” than narrowband i.e. wideband O2 sensor has “bandwidth” from 7.35 to 22 and precisely change output signal fallowing this. Where are VSR max and VSR min for simulated is unknown. Do you compare simulated and stock signals in this very rich/lean conditions?!!

    Narrowband sensor has different “logic”/construction i.e. very fast jumping between 5 levels which represent state of gases and ECU logic calculates adjustment of fuel based on this. VSR max/min are somehow designed in sensor.

    I use LC controller more than 2 years. The config of controller allow to adjust min/max and stoich Voltage values for both simulated and WO2. Even during heating and error you can set constant output values 0.45 V or 2.5 Volts to avoid DTC codes and creasy mixtures. Then you don’t need to change any limits in code.

    If other values for injector constant, injector delay and etc. are set correct you must not have any DTS problem. Just lambda adjustment calculation will have some delay and mixture problems with simulated narrowband sensor.

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    • #17
      I use the LC-1 in standard configuration, nothing changed. Keep it simple.
      Didn't compared the maximum voltage, noticed a lot of people have the same DTC, so I looked for the reason.
      DTC and lambda integrator are not connected in the code.

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