987 · Electrical

P0641

Sensor Reference Voltage "A" Circuit Open

MED SEVERITY

Open circuit on a sensor 5V reference supply from the control module.

SYMPTOMS

  • Check-engine light
  • Multiple sensor codes
  • Drivability issues

LIKELY CAUSES

  • Short or open on the reference circuit
  • Shorted sensor pulling the reference down
  • Module fault

DIAGNOSIS STEPS

  • Identify sensors sharing the reference
  • Check the reference circuit for shorts/opens
  • Disconnect sensors to isolate

RELATED PARTS

  • Wiring harness
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