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T17:C34 CPU Temperature Fault

CPU Temperature Fault (Major Recoverable)

Allen-Bradley · Logix 5000 Controllers

What does T17:C34 CPU Temperature Fault mean?

This specific code identifies a major recoverable fault, indicating that the controller's internal temperature has exceeded its defined major fault threshold. The fault is recorded in the major fault log and displayed on the front panel as 'T17:C34 CPU Temperature Fault'. If the fault is not cleared by a fault handler in the user program, the module will transition into fault mode.

Common Causes

  • Controller internal temperature exceeding the major fault threshold
  • Absence or incorrect implementation of fault handling logic to clear the T17:C34 fault in the application program

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Examine the major fault log for specific timestamp and conditions leading to T17:C34

  2. 2

    Review the application logic for any configured fault handlers and verify their functionality to clear T17:C34

  3. 3

    Measure the ambient temperature within the control panel enclosure using a calibrated thermometer

  4. 4

    Visually inspect controller heatsinks and cooling vents for dust accumulation or obstructions

  5. 5

    Verify the operational status of any enclosure cooling fans or air conditioning units, confirming proper setpoints

Browse all codes in this manual (17)
Verified technical data. Last updated: April 2026

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Source: Allen-Bradley Logix 5000 Controllers
Open Manual (Page 51)Search more codes in this manual