DTC Description

P219600 is set when the signal characteristics of the O2 Sensor (UP) and (DOWN) differ from each other.

The ECM determines the air-fuel ratio by comparing the downstream oxygen sensor signal with the upstream oxygen sensor signal.

Case 1) Upstream oxygen sensor signal is lean + Downstream oxygen sensor signal is rich + Air-fuel ratio control value reaches the limit

Case 2) Upstream oxygen sensor signal is rich + Downstream oxygen sensor signal is lean + Air-fuel ratio control value reaches the limit