EGR Problem

1992 GMC Magnavan 5.7 KSECTION 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.

CODE 45 ECM TERMINAL & CIRCUIT WIRING ID (ALL W/4L80-E A/T)

Application ECM Terminal Wire Color
O2 Sensor Signal C14 Purple
O2 Sensor Ground C13 Tan
CODE 45 ECM TERMINAL & CIRCUIT WIRING ID (ALL OTHERS)

Application ECM Terminal Wire Color
O2 Sensor Signal D7 Purple
O2 Sensor Ground D6 Tan
Fig 1: Code 45 Schematic (Except 4.3L Turbo) 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:

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