Cold start engine control diagnostic systems and methods

Abstract

An engine control module includes a spark control module, an engine speed module, a residual determination module, and a metric determination module. The spark control module actuates spark plugs based on a commanded spark timing. The engine speed module determines a desired engine speed based on an engine temperature and a period of time an engine is in operation after a cold start. The residual determination module determines a desired spark timing based on the desired engine speed, and determines a residual spark timing based on a difference between the commanded spark timing and the desired spark timing. The metric determination module detects a spark timing fault based on the residual spark timing and a predetermined spark timing range.

Dependencies are inferred from the claim text.