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1999 TOYOTA TACOMA
2.7L I4•RWD•AUTOMATIC•gas
5 active safety recalls on this vehicle — view recalls
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Repairs0Labor1038Torque1596Fluid17DTC3336Battery2Maintenance0Recalls5
P0944high severityPowertrain

Hydraulic Pressure Unit Loss of Pressure

on 1999 Toyota Tacoma 2.7L I4 · RWD

What this code means

The transmission hydraulic system has lost pressure. This usually indicates a major leak, a failed pump, or a stuck valve preventing proper pressure buildup.

Symptoms

  • Transmission slipping
  • No shifting or stuck in gear
  • Transmission warning light on

Common causes

  • Faulty hydraulic pump
  • Major internal transmission leak
  • Low transmission fluid
  • Stuck pressure control valve

Diagnostic steps

  1. Check transmission fluid level and condition
  2. Test line pressure with a gauge
  3. Inspect for internal and external leaks
  4. Test pump and pressure control solenoid operation
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