BCM Status Lights

While in diagnostics, the liquid crystal displays on the Electronic Climate Control (ECC) panel are used to indicate the status of various inputs and operating conditions. See Figure . The meaning of each word or symbol on the ECC panel will change depending on whether the BCM or ECM system level is selected. The following is a description of what each word and symbol represents in the ECM system:

• OFF
  
  The "OFF" status indicator is turned on whenever the BCM commands the air inlet valve to the recirculation position.
• AUTO
  
  The "AUTO" status indicator is turned on whenever the up-down air control switch on the CCP is in the "Normal" position.
• FRONT DEFOG
  
  The front defog status indicator is turned on whenever the BCM is requesting the ECM to engage the A/C compressor clutch. The light does not indicate whether the clutch is enabled or disabled by the ECM. Actual operation depends on the ECM and on the integrity of the compressor clutch system.
• REAR DEFOG
  
  The rear defog status indicator is turned on whenever the BCM senses that the low refrigerant pressure switch is open. The light should remain off if the refrigerant system is fully charged, unless the high side refrigerant temperature drops below -5°F (-21°C). Below -5°F (-21°C), the low refrigerant pressure switch will open due to the temperature/pressure relationship of freon.
• LO FAN
  
  The "LO FAN" status indicator is turned on whenever the BCM is commanding the A/C-DEF mode door to divert air flow to the A/C outlets, as in the A/C or normal purge modes.
• HI FAN
  
  The "HI FAN" status indicator is turned on whenever the BCM is commanding the HVAC Programmer to not supply vacuum to the park brake release motor (park brake remains applied). The light is off when the BCM commands the park brake to be released.