EGR Problem

1995 GMC Suburban K2500, 6.5 FSECTION EGR Problem
WARNING: This page does not describe the selected car, but rather 19 other vehicles, including the 1996 Chevrolet Chevy Van, 1995 GMC Vandura Special, 1995 GMC Vandura, 1995 GMC Sonoma, and 1995 GMC Safari. However, it is still accessible from the selected car via links, so may be relevant.

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 - GASOLINE article.

CODE 45 TERMINAL & CIRCUIT WIRING IDENTIFICATION

Application ECM/PCM Terminal Wire Color
"C" & "K" Series
4.3L
Oxygen Sensor Signal A10 Purple
Oxygen Sensor Ground A12 Tan
"G" Series
4.3L A/T
Oxygen Sensor Signal A10 Purple
Oxygen Sensor Ground A12 Tan
"L" & "M" Series
4.3L
Oxygen Sensor Signal A10 Purple
Oxygen Sensor Ground A12 Tan
"P" Series
4.3L
Oxygen Sensor Signal A10 Purple
Oxygen Sensor Ground A12 Tan
"S" & "T" Series
4.3L (VIN W) Pickup & A/T Utility
Oxygen Sensor Signal A10 Purple
Oxygen Sensor Ground A12 Tan
4.3L (VIN Z) A/T Pickup
Oxygen Sensor Signal A10 Purple
Oxygen Sensor Ground A12 Tan
Fig 1: Code 45 Schematic (4.3L) Rich Exhaust Indication
G91H07378
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.