Make a test circuit (cheap 2 resistors used instead of the LSU4 sensor) for initial WBO2 pump_pw_zero and nernstdc_target (or even pump PID) calibration:

Pump- (100Ohm) Nernst (100 Ohm) Pump+

Typical voltages with wbo2 OFF (engine not running, trigger signal not played)

Typical voltages with wbo2 ON (engine running or trigger signal played or wbo2 forced on with mde02 command)

Misc notes

Don't connect real sensor until PID (and nernst_dc_target) is tuned with that so nernst is stable and fine (450mV above pump- ).


See also: