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P0598moderate severityPowertrain

Thermostat Heater Control Circuit Low

on 2014 Chevrolet Silverado 1500 5.3L V8 EcoTec3 L83 · RWD

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

Other Powertrain codes on this vehicle

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