Component Diagnostic Charts

Chart C-6C - Air Management Check (Electronic Air Control Valve):

Wiring Diagram For Chart C-6C - Air Management Check (Electronic Air Control Valve):

CHART C-6C - AIR MANAGEMENT CHECK (ELECTRONIC AIR CONTROL VALVE)

Circuit Description:

An electric air control valve solenoid directs air into the exhaust ports or the air cleaner. During cold start the ECM completes the ground circuit, the EAC solenoid is energized, and air is directed to the exhaust ports. As "coolant" temperature increases, or system goes to "Closed Loop", the ECM opens the ground circuit, the EAC solenoid is de-energized, and air goes to the air cleaner. If the system is not operating properly, check manifold vacuum signal (10" Hg (34 kPa) at the valve and check the electrical circuit from the solenoid to the ECM.


Test Description: Numbers below refer to circled numbers on the diagnostic chart.

1. This is a system performance test. When vehicle goes to "Closed Loop", air will switch from the ports and divert to the air cleaner.

2. Tests for a grounded electric divert circuit. Normal system light will be "OFF".


3. Checks for an open control circuit. Grounding diagnostic terminal will energize the solenoid, if ECM and circuits are normal. In this step, if test light is "ON", circuits are normal and fault is in valve connections or valve.

4. Checks for voltage from battery through a fuse to the solenoid.