34
Thermo King
Warning

Check Modulation Circuit

The unit detected a problem in the modulation valve electrical circuit.

Possible causes

  • Burnt modulation valve coil
  • Loose or corroded electrical connection
  • Controller board output failure
  • Short-circuited wiring

Recommended actions

  • Measure valve coil resistance
  • Clean modulation circuit connectors
  • Verify output voltages from the microprocessor
  • Inspect the wiring harness

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