Diagnostic Aids

1995 GMC Suburban K2500, 6.5 FSECTION Diagnostic Aids
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 1995 GMC Vandura, 1995 GMC Rally, 1995 GMC Pickup, 1995 Chevrolet Sportvan, and 1995 Chevrolet Pickup. However, it is still accessible from the selected car via links, so may be relevant.

Verify a clean, tight connection for sensor ground. An open circuit at sensor signal terminal or ground terminal will result in a Code 13.

CODE 13 TERMINAL & CIRCUIT WIRING IDENTIFICATION

Engine Application ECM/PCM Terminal Wire Color
"C" & "K" Series
5.0L A/T
O2 Sensor Signal A10 Purple
O2 Sensor Ground A12 Tan
5.0L M/T
O2 Sensor Signal D7 Purple
O2 Sensor Ground D6 Tan
"G" Series
5.0L A/T
Oxygen Sensor Signal A10 Purple
Oxygen Sensor Ground A12 Tan
Fig 1: Code 13 Schematic (5.0L) Open Oxygen Sensor Circuit
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.