EGR Problem

EGR valve sticking open at idle is usually accompanied by a rough idle and/or stalling. If Code 45 is intermittent, see INTERMITTENTS in TESTS W/O CODES article in this section.

CODE 45 ECM TERMINAL & CIRCUIT WIRING IDENTIFICATION

Application	ECM Terminal	Wire Color
All With 4L80-E
Oxygen Sensor Signal	C14	Purple
Oxygen Sensor Ground	C13	Tan
All Others Except 3.8L
Oxygen Sensor Signal	D7	Purple
Oxygen Sensor Ground	D6	Tan

Fig 1: Code 45, Schematic, Rich Exhaust Indication

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code 45, Flow Chart, Rich Exhaust Indication

Courtesy of GENERAL MOTORS CORP.