Code 1-4-3 (Knock Sensor Signal)

1991 Volvo 940 Turbo, 4D Sedan, AW71SECTION Code 1-4-3 (Knock Sensor Signal)

Disconnect knock sensor connector and jumper terminals. Measure resistance between terminals No. 12 (Black wire) and No. 13 (Green wire). Resistance should be zero ohms. If resistance is okay, replace knock sensor. If resistance is too high, wiring is faulty.

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.