Diagnostic Procedures
WARNING: This page is about a different car, the 1998 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES (DTCS) under SELF-DIAGNOSTICS. Cycle ignition. Check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS) under SELF-DIAGNOSTICS. If DTC B1656 or B1658 is current, replace MMM.