GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2001 🢒 Catera 🢒 Engine 🢒 Engine Controls - 3.0L (L81) 🢒 Intake Resonance Switchover Valve Replacement

Removal Procedure

    Object Number: 661778 Size: SH
  1. Loosen the hose clamps and remove the upper air ducts (1, 2) that connect to the throttle body.
  2. Disconnect the vacuum hose (4) from the actuator diaphragm (12).
  3. Remove the intake air resonator nuts (9) that attaches the resonator to the fan shroud. This will allow access to the lower air duct clamps.
  4. Loosen the lower air duct clamps and remove the switchover valve assembly (3).

    5. Object Number: 661923 Size: SH
  5. Remove the bolts (1) that retain the valve in the housing.
  6. Remove the intake resonance switchover valve bolts.

Installation Procedure

    Object Number: 661923 Size: SH
  1. Install the switchover valve into the switchover valve housing.

    2. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  2. Install the intake resonance switchover valve bolts.

    3. Tighten
    Tighten the bolts to 8 N·m (71 lb in).


    Object Number: 661778 Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  3. Install the switchover valve assembly (3) into the lower air ducts.

    4. Tighten
    Tighten the air intake duct hose clamps to 3 N·m (27 lb in).

  4. Install the intake air resonator nuts that attaches the resonator to the fan shroud.

    5. Tighten
    Tighten the nut to 3 N·m (27 lb in).

  5. Connect the vacuum hose to the actuator diaphragm.
  6. Install the upper air ducts that connect to the throttle body to the intake air resonance switchover valve assembly.

    7. Tighten
    Tighten the air intake duct hose clamps to 3 N·m (27 lb in).

  7. Inspect for leaks.