Ford Full-Size Cars 1968-1988 Repair Guide

Bypass Air Idle Speed Control


The air bypass solenoid is used to control the engine idle speed and is operated by the EEC module.

The valve allows air to pass around the throttle plates to control:

Cold engine fast idle
Cold starting
Dashpot operation
Over-temperature idle boost
Engine load correction

This valve is not serviceable. Therefore if defective the entire valve must be replaced.