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 Transmission ⁽¹⁾

Oxygen Sensor Signal

C14

Purple

Oxygen Sensor Ground

C13

Tan

2.5L, 2.8L, 3.1L & "C", "K" & "P" Series 4.3L ⁽¹⁾ & V8 (All With M/T)

Oxygen Sensor Signal

Purple

Oxygen Sensor Ground

Tan

⁽¹⁾	The 4.3L oxygen sensor has 3 wires: sensor signal, common ground and heating element.

Fig 1: CODE 45, Schematic, Rich Exhaust Indication

Fig 2: CODE 45, Flowchart, Rich Exhaust Indication