DTC 19, Crankshaft Position Reference Error: Notes

1995 GMC Forward Control 4.3 Z, StandardSECTION Notes

Crankshaft position sensor is a Hall Effect type sensor that monitors crankshaft position and speed There are 4 teeth 90 degrees apart on front of crankshaft sprocket that induce an alternating current in sensor which is transmitted to PCM. DTC 19 will set when 8 crankshaft position pulses are missed for every cam reference pulse. PCM will default to backup fuel.

NOTE: Test numbers refer to numbers on diagnostic chart.
  1. This step determines if DTC 19 is result of a hard failure or an intermittent condition.
  2. This step checks 5-volt reference circuit.
  3. This step checks ground circuit.
  4. This step checks sensor and harness wiring.
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.