Circuit Description

WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.

DTCs P0301-P0304 are cylinder specific misfire codes. Each cylinder is monitored individually for a misfire condition and can set a cylinder specific DTC. Powertrain Control Module (PCM) uses the Crankshaft Position (CKP) sensor and Camshaft Position (CMP) sensor to determine engine misfire. CKP and CMP sensor monitor their respective components and evaluate changes in crankshaft rotational speed for each cylinder. Irregular changes in crankshaft rotational speed indicate a possible misfire. The Malfunction Indicator Light (MIL) illuminates when misfire rate equals or exceeds a pre-determined count. A misfire rate that is high enough can cause the catalytic converter to overheat under certain driving conditions. MIL will flash ON and OFF when the conditions for catalytic converter overheating are present.