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ECM Code E90: VCC Brake Switch Input Problem: Action

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.

ECM will set Code E90 and turn on SERVICE ENGINE SOON light.

Fig 1: Code E90: Circuit Diagram & Flow Chart