DTC P1609 - Engine Control Module (CPU) Malfunction: Condition

DTC is set when Engine Control Module (ECM) does not read DTCs from output devices. Cause is malfunctioning ECM. Replace ECM and erase any DTCs present. See CLEARING CODES  in SELF-DIAGNOSTIC SYSTEM section. Retest vehicle.

DTC is set when ECM's knock control integrated circuit is damaged. Cause is malfunctioning ECM. Replace ECM and erase any DTCs present. See CLEARING CODES  in SELF-DIAGNOSTIC SYSTEM section. Retest vehicle.