Status Light Displays(ECM)

While in diagnostic service mode, the lights on the Climate Control Panel (CCP) function buttons indicate status of various operating modes. 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 different modes of operation are indicated by the light being either on or off. Lights and the mode they represent are as follows:

1. "OFF" Button
   
   This light is illuminated when left oxygen sensor indicates a rich exhaust mixture (not enough oxygen). The light will be off when the signal indicates a lean mixture (too much oxygen). It should flicker on and off during warm steady throttle operation to verify that the oxygen sensor is providing signals to the ECM and that the ECM is in closed loop operation.
2. "ECON" Button
   
   This light is illuminated when right oxygen sensor indicates a rich exhaust mixture (not enough oxygen). The light will be off when the signal indicates a lean mixture (too much oxygen). It should flicker on and off during warm steady throttle operation to verify that the oxygen sensor is providing signals to the ECM and that the ECM is in closed loop operation.
3. "AUTO" Button
   
   This light is illuminated when ECM is operating in "closed loop" fuel control mode. This light should come on when the coolant temperature and oxygen sensors reach normal operating temperature.
4. "FRONT DEFOG"
   
   This light is illuminated whenever ECM commands A/C clutch engagement through the A/C clutch relay. This light should be on if the BCM is in control of the A/C clutch. The light will be off if the ECM is commanding A/C clutch disengagement.
5. "REAR DEFOG"
   
   This light indicates when ECM is commanding the Viscous Converter Clutch (VCC) to engage. The light only indicates whether the VCC is enabled or disabled by the ECM. Actual operation depends on the integrity of the VCC system.
6. "C"
   
   This status indicator is turned on whenever ECM senses that 3rd gear pressure switch is open. The light should be on while in 3rd gear operation.
7. "F"
   
   This status indicator is turned on whenever ECM senses that 3rd and 4th gear pressure switches are open. The light should be on while in 4th gear operation and ECM had received a 3rd gear input signal.
8. "E"
   
   This status indicator is turned on whenever ECM senses that 4th gear pressure switch is open, but not 3rd gear switch. This light should be on while in 4th gear operation and ECM had not received a 3rd gear input signal.
9. "LOW FAN"
   
   This status indicator is turned on whenever the throttle switch is closed, indicating the ISC motor is controlling the idle speed. The light should be on when the throttle is not pushed.
10. "NORM FAN"
    
    This status indicator is turned on whenever the Park/Neutral switch is closed indicating that the vehicle is in Park or Neutral.