P00200
Carrier Transicold
Warning

Check UL1 Cylinders

Mechanical or control error in the cylinders associated with unloader 1 (UL1).

Possible causes

  • Stuck UL1 solenoid valve
  • Broken head gasket
  • Internal pneumatic/mechanical failure

Recommended actions

  • Check compressor sound change when UL1 is activated
  • Remove and clean solenoid
  • Check valve plate

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