Status Light Indicators: ECM

Following is a brief summary of ECM system status lightindicator operation:

*  LOOP light (CRT equipped) or HIGH light (ECCP equipped) is on when ECM is in closed loop fuel control. Light comes on only after coolant and O2 sensors reach operating temperature.

*  TCC light (CRT equipped) or MED light (ECCP equipped) only indicates whether operation has been commanded by ECM. Actual TCC engagement depends upon TCC system being in working order.

*  OXY light (CRT equipped) or LOW light (ECCP equipped) stays on when oxygen sensor signals rich exhaust condition to ECM. Light will flash on and off during warm engine, steady throttle and proper fuel mix condition.

*  4th gear light (CRT equipped) or VENT light (ECCP equipped) will be on when ECM commands 4th gear to engage. Light should be on only in 4th gear.

*  3rd gear light (CRT equipped) or AUTO light (ECCP equipped) will be on when ECM commands 3rd gear to engage. Light should be on in 3rd and 4th gears.

*  2nd gear light (CRT equipped) or "°C" light (ECCP equipped) will be on when ECM commands 2nd gear to engage. Light should be on in 2nd, 3rd and 4th gears.

*  A/C compressor command upper arrow (ECCP equipped) or COMP light (CRT equipped) will be on only when ECM allows A/C clutch engagement through A/C relay. Light will also be on if BCM requests ECM to turn clutch on during test sequence. Light should be off if ECM commands disengagement.