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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
P0605high severityPowertrain

Internal Control Module Read Only Memory (ROM) Error

on 2003 Toyota Tacoma 2.7L I4 · RWD

What this code means

The PCM detected a fault in its Read Only Memory, where the program calibration is stored. This usually indicates corrupt software or an internal module failure.

Symptoms

  • Check engine light on
  • Engine may not start
  • Erratic engine operation

Common causes

  • Corrupt or failed PCM ROM
  • Internal module hardware failure
  • Failed software update
  • Voltage supply issues

Diagnostic steps

  1. Verify battery voltage and grounds
  2. Check PCM power supply circuits
  3. Attempt PCM reflash with correct calibration
  4. Replace PCM if reprogramming fails
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