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2018 TOYOTA CAMRY
2.5L I4•FWD•AUTOMATIC•gas•A25A-FKS
8 active safety recalls on this vehicle — view recalls
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Repairs413Labor483Torque4163Fluid7DTC1638Battery1Maintenance0Recalls8
P0598moderate severityPowertrain

Thermostat Heater Control Circuit Low

on 2018 Toyota Camry 2.5L I4 · FWD

What this code means

The thermostat heater control circuit voltage is too low. A short to ground or failed heater element is the likely cause.

Symptoms

  • Check engine light illuminated
  • Poor engine temperature control
  • Reduced fuel economy

Common causes

  • Short to ground in heater circuit
  • Faulty heated thermostat
  • Damaged wiring harness
  • PCM output fault

Diagnostic steps

  1. Read thermostat heater codes
  2. Check circuit for short to ground
  3. Inspect harness near thermostat
  4. Measure control voltage during operation
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