DTC P1646, P1647: A/F Sensor Control Chip: Notes

DTC P1646, P1647 CHART (MZI-3.7)

DTC P1646 DTC P1647	A/F sensor (RH) control chip A/F sensor (LH) control chip
DETECTION CONDITION	P1646 indicates the A/F sensor (RH) control chip P1647 indicates the A/F sensor (LH) control chip The PCM monitors the application-specific integrated circuit that controls and monitors the HO2S. The test fails when the PCM detects an internal circuit or communication concern.
POSSIBLE CAUSE	PCM malfunction