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Note on Intermittents

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.

Display ECM parameter P.0.1. Manipulate TPS wiring and connectors. Watch for TPS valve to jump or skip. Enter output cycling and manipulate ISC wiring and connectors. Watch for ISC to stop cycling. Enter diagnostics and observe throttle switch status light (OFF). Check for binding throttle linkage or weak throttle return spring. If status light flashes, check for intermittent open circuit on circuit No. 427. Verify minimum air RPM, ISC and TPS are set to specification.

Fig 1: Code E30: Circuit Diagram
G90A17269
Fig 2: Code E30: Flow Chart
G90J14760