Test Conditions
WARNING: This page is about a different car, the 1990 Cadillac Fleetwood and 1990 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
Codes E21, E22, E26 and E27 are clear. ECM tests for Code E55 at key off. At key off, ISC will retract until throttle switch opens, TPS value is read by ECM, and a correction factor value is the same on 2 consecutive key-off cycles. TPS setting is then relearned.