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2003 TOYOTA TACOMA
2.7L I4•RWD•AUTOMATIC•gas•3RZ-FE
5 active safety recalls on this vehicle — view recalls
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Repairs0Labor1066Torque2197Fluid17DTC3480Battery2Maintenance0Recalls5
P0542low severityPowertrain

Intake Air Heater Circuit High

on 2003 Toyota Tacoma 2.7L I4 · RWD

What this code means

The PCM detected a high voltage condition in the intake air heater circuit. The heater is used to warm intake air for better cold starting on diesel engines.

Symptoms

  • Hard cold starting
  • Extended crank time
  • Check engine light on

Common causes

  • Open in heater circuit wiring
  • Faulty intake air heater relay
  • Corroded or loose connector
  • Failed heater element

Diagnostic steps

  1. Inspect heater wiring for opens
  2. Check relay and connector integrity
  3. Measure heater element resistance
  4. Verify PCM control and voltage supply
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