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1998 TOYOTA TACOMA
2.7L I4•RWD•AUTOMATIC•gas
5 active safety recalls on this vehicle — view recalls
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Repairs0Labor1047Torque1633Fluid17DTC3334Battery2Maintenance0Recalls5
P0643moderate severityPowertrain

Sensor Reference Voltage A Circuit High

on 1998 Toyota Tacoma 2.7L I4 · RWD

What this code means

The PCM detected the sensor reference voltage on circuit A is above normal. This can cause incorrect readings from affected sensors.

Symptoms

  • Multiple sensor codes
  • Check engine light on
  • Erratic performance

Common causes

  • Short to voltage on reference circuit
  • Damaged wiring
  • Corroded connector
  • Faulty PCM

Diagnostic steps

  1. Measure reference voltage at sensors
  2. Inspect wiring for short to power
  3. Isolate affected circuit
  4. Repair wiring or replace PCM
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