Status Lights Display
While in self-diagnostic mode, mode indicators on ECC panel automatically indicate system operating modes; different modes of operation are indicated by illuminated or non-illuminated status lights. Following is a description of various status lights and their relation to system operations.
- AUTO Status Indicator - This indicator is turned on whenever PCM is operating in "closed-loop" fuel control. See Fig 1
. This light should come on after coolant and oxygen sensors have reached normal operating temperatures.NOTE: A/C compressor clutch operates at extended interval during diagnostic mode.
- AUTO FAN Status Indicator - This status indicator is turned on when signal from coolant fan control relays indicates fans are commanded on. See Fig 1 . This light should be off when fans are commanded off.
- Temp. °C (Centigrade) Status Indicator - This indicator is turned on when BCM is commanding heater valve to block coolant flow through heater core. See Fig 1 . This light should remain off except when air-mix door is being commanded to maximum A/C position (0%).
- ECON Status Indicator - This indicator is used for oxygen sensor signal. Indicator is on for rich exhaust condition. See Fig 1 . Indicator should toggle on and off with a warm engine and steady throttle.
- °F (Fahrenheit) Status Indicator - This indicator is turned on when BCM senses refrigerant low pressure switch or circuit is open. See Fig 1 . This light will come on when ambient temperature falls below approximately -5°F due to pressure temperature relationship of R-12. This light should remain off if A/C system is fully charged and properly controlled.
- Front Defog Status Indicator - This indicator is used for Viscous Converter Clutch (VCC). See Fig 1 . Light only indicates whether PCM is commanding VCC solenoid to energize or de-energize. Actual operation depends on integrity of VCC system.
- HI FAN Status Indicator - This indicator is turned on when BCM is commanding up-down mode door to divert airflow down to heater outlet. See Fig 1 . This light will be off when ECC system is in normal purge modes.
- LO FAN Status Indicator - This indicator is turned on when BCM is commanding A/C defrost mode door to divert airflow to A/C outlets, as in A/C or normal purge modes. See Fig 1 . This light will be off when ECC system is in heater defrost and cold purge modes.
- OFF Status Indicator - This indicator is turned on when PCM senses ISC motor throttle switch. See Fig 1 . This light should be off when engine RPM is above idle.
- OUTSIDE TEMP Status Indicator - This indicator is turned on when BCM is requesting A/C compressor clutch to engage. See Fig 1 . This light only indicates whether clutch is enabled or disabled by BCM. Actual operation depends on system integrity.
- Rear Defog Status Indicator - This indicator is used for 4th gear pressure switch. See Fig 1 . This light should only be on in 4th gear.