Idle Air/Vacuum Signal Housing

REMOVE OR DISCONNECT:

1. Negative battery terminal.
2. Vacuum harness connector.
3. IAC valve electrical connector.
4. Idle Air Control (IAC) valve.
5. Idle air/vacuum signal housing screws.
6. Idle air/vacuum signal housing assembly and gasket. Discard gasket.
7. Clean gasket mounting surfaces to ensure a good seal.

NOTE: Use care in cleaning old gasket material from machined aluminum surfaces. Sharp tools may damage sealing surfaces.

INSTALL OR CONNECT:

1. New idle air/vacuum signal assembly gasket.
2. Idle air/vacuum signal housing assembly.
3. Idle air/vacuum signal housing screws. Tighten idle air/vacuum signal housing screws (starting in center and moving outward) to 3.4 Nm (30 in lb).
4. Measure Distance between tip of IAC valve pintle and mounting flange.
- If greater than 28 mm, use ringer pressure to slowly retract the pintle. The force required to retract the pintle of a new valve will not cause damage to the valve.
5. Lubricate IAC valve O-ring with clean engine, oil.
6. IAC valve assembly.
7. Attaching screws. Tighten IAC valve attaching screws to 3.0 Nm (27 in lb).
8. IAC valve electrical connector.
9. Vacuum harness connector.
10. Negative battery terminal.
11. Perform the "Idle Learn Procedure." The ECM will need to relearn the IAC valve pintle position following battery reconnect.

Idle Air/Vacuum Signal Housing:

This procedure may be performed without removing the throttle body from the intake manifold plenum.

REMOVAL:

1. Remove the idle air control valve, see IDLE AIR CONTROL VALVE.
2. Remove the idle air/vacuum signal housing screws.
3. Remove the idle air/vacuum signal housing assembly.
4. Remove the idle air/vacuum signal assembly gasket, and discard.
5. Clean the mounting surfaces to ensure a good seal.

INSTALLATION:

1. Locate the idle air/vacuum signal housing assembly, with new gasket in position on the throttle body.
2. Install idle air/vacuum signal housing screws, and tighten screws (starting in the center and moving outward) to 3.4 Nm (30 in lb).

Idle Air Control (IAC) Valve:

3. If installing a new IAC valve:
^ Measure the distance between the tip of the IAC valve pintle and the mounting flange.
^ If greater than 28 mm, use finger pressure to slowly retract the pintle. The force required to retract the pintle of a new valve will not cause damage to the valve.
4. Lubricate the IAC valve O-ring with clean engine oil, and install the O-ring on the IAC valve.
5. Install the IAC valve assembly.
6. Install the IAC valve attaching screws, and tighten to 3.0 Nm (27 in lb).

IDLE LEARN PROCEDURE: Any time the battery is disconnected, the programmed position of the IAC valve pintle is lost, and replaced with a default value. To return the IAC valve pintle to the correct position, perform the following procedure:

1. After restoring battery power, connect the Tech 1 "SCAN" tool.
2. Select "IAC SYSTEM," then select "IDLE LEARN" in the "MISC TEST" mode.
3. Proceed with idle learn as directed.
^ This procedure allows the ECM memory to be updated with the correct IAC valve pintle position, for the vehicle, and provide a stable idle speed.