If the drivers door is opened with the ignition off and the lamps on, a warning chime will sound. This indicates that the headlamps are still on.
Chevrolet Cobalt Service & Repair Manual. Component Service
Engine Control Module (ECM)
1.
Retrieve percentage of remaining engine
oil life using a scan tool, then record remaining engine oil life.
2.
Remove ECM cover, then disconnect body
wiring harness electrical connector from ECM, Fig. ...