Notes On Intermittents

PCM Code P085 may set due to an engine overheated condition in which PCM will only allow engine to run on 4 cylinders, causing a high idle throttle angle. If this occurs, clear PCM Code P085, reset idle learn using PCM override PS13 and perform TP sensor/idle learn.

Fig 1: Code P085 Schematic, Idle Throttle Angle Too High

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code P085 Diagnostic Flow Chart, Idle Throttle Angle Too High

Courtesy of GENERAL MOTORS CORP.