Status Lights

On Board Diagnostic Flow Chart (Part 2 of 2):

While in the ECM system level, in the diagnostic service mode, the mode indicators on the Climate Control Panel (CCP) of the CCDIC are used to indicate the status of certain operating modes. The different modes of operation are indicated by the status light being illuminated or turned off.

A brief summary of each status light is provided below:

1. The "REAR DEFOG" status indicator is illuminated whenever the 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.

2. The "AUTO" Status indicator is illuminated whenever the ECM is operating in "closed loop" fuel control. This light should come on after the coolant and oxygen sensors have reached normal operating temperatures.

3. The "ECON" status indicator is illuminated whenever the oxygen sensor signal to the ECM indicates a "rich" exhaust condition. This light should switch between "rich" and "lean" (flash on and off) during warm steady throttle operation.

4. The "C" status indicator is illuminated whenever the ECM senses that the 3rd gear pressure switch is open. The light should be on while in 3rd gear operation.

5. The "F" status indicator is illuminated whenever the ECM senses that the 3rd and 4th gear pressure switches are open. The light should be on while in 4th gear operation, and the ECM has received a 3rd gear input signal.

6. The "E" status indicator is illuminated whenever the ECM senses that the 4th gear pressure switch is open, but not the 3rd gear switch. The light should be on while in 4th gear operation and the ECM had not received a 3rd gear input signal.

7. The "FRONT DEFOG" status indicator is illuminated whenever the ECM is commanding the ECC compressor clutch to engage. The light indicates whether the clutch is enabled or disabled by the ECM but actual operation depends on the integrity of the compressor clutch system.

8. The "LO FAN" status indicator is illuminated whenever the ECM senses that the throttle switch is closed. The light should be on whenever the driver's foot is off the accelerator pedal.

9. The "NORM FAN" status indicator is illuminated whenever the ECM senses that the PRDNL sensor is indicating that the transmission is in PARK or NEUTRAL. The light should be off in all gears except PARK and NEUTRAL.