Code 212 = Loss of IDM (Ignition Diagnostic Monitor) input to EEC or SPOUT circuit grounded.... 1. Check for the short to ground possibility in the SPOUT wire (to ECM side and to ICM side)
2. IDM wire from Ignition Control Module (ICM) to ECM integrity (open, short to ground or power).
3. Was ICM already replaced
4. If all the above checks OK......the ECM will be the one to blame.