Porsche Boxster/911 Climate Control

Important: Use this guide if you reinstalled your repaired (Porsche Boxster/911 Climate Control) and the problem is still happening.

• Step 1: Confirm what’s failing
  • Display is dim/blank
  • Backlighting is dim/doesn’t light
  • LCD is pixelated/bleeding/missing segments
  • Buttons respond but screen issues remain
  • Buttons do not respond / intermittent response
• Step 2: Quick power reset (easy win)
  • Turn key off, remove key, wait 2 minutes, then restart and re-test
  • If symptoms change with the reset, focus on power/ground and connector fitment
• Step 3: Check fuses and HVAC power feeds
  • Check the HVAC/CCU fuse(s) and any related interior electronics fuses
  • Replace any blown fuse once and re-test
  • If a fuse blows again, stop and inspect for a short in the vehicle
• Step 4: Reseat connectors (most common after reinstall)
  • Remove/reinstall the climate control module and ensure connectors are fully seated and latched
  • Inspect for bent pins, pushed-out pins, corrosion/green pins, or loose connector fit
  • Wiggle-test the harness with the key on (watch for flicker/dimming or intermittent operation)
• Step 5: Verify illumination/dimmer behavior
  • If the display/backlight changes when you adjust the dimmer/headlights:
    • Inspect the vehicle’s dimmer/illumination circuit and ground points
  • If the unit is dark only at night/headlights on:
    • That’s commonly an illumination feed or dimmer input issue (vehicle-side)
• Step 6: Check battery voltage and grounds
  • Low voltage or poor ground can cause dim display, flicker, resets, or button glitches
  • Confirm stable battery voltage and inspect grounds in the console/dash area if symptoms are intermittent
• Step 7: Separate “display problem” vs “HVAC system problem”
  • If the display works but airflow/temp won’t change:
    • Suspect vehicle-side issues (blend/mode actuators, blower resistor/module, wiring, or HVAC control motors)
  • If blower works only on certain speeds:
    • Suspect blower resistor/module or blower power/ground (vehicle-side)
• Step 8: Scan for HVAC-related fault codes
  • Scan the vehicle and record any HVAC/comfort system codes
  • Clear codes, operate the system, then re-scan
  • Codes pointing to actuators/sensors/network issues usually indicate a vehicle-side fault
• Step 9: If the issue is still present
  • Call or email UpFix for the fastest help, especially if the problem happens immediately after install