GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2005 🢒 Rendezvous - AWD 🢒 Engine 🢒 Engine Controls - 3.6L (LY7) 🢒 Intake Manifold Runner Control System Diagnosis

Circuit Description

An intake manifold runner control (IMRC) valve is used to change the intake manifold plenum configuration. When the IMRC valve is open, the intake manifold is configured to one large plenum. When the IMRC valve is closed, the intake manifold is configured to 2 smaller plenums. The IMRC valve improves engine performance at low and high engine speeds.

Ignition voltage is supplied to the IMRC solenoid. The engine control module (ECM) controls the solenoid by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback circuit that is pulled-up to a voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.

The ignition voltage circuit and the IMRC control circuit are routed to the IMRC solenoid through an IMRC driver module. The IMRC driver module is an amplifier that is used to strengthen the IMRC solenoid's ability to remain in the commanded position during high load and current demands.

Diagnostic Aids
    • Inspect the IMRC solenoid valve for witness marks that indicate that the valve was hitting the intake manifold. This condition may be temperature related.
    • An open circuit condition within the IMRC driver module, the wiring from the module to the IMRC solenoid, or the solenoid itself will not set a DTC.
    • A short circuit condition within the IMRC driver module will open the ignition voltage supply fuse, and cause DTCs unrelated to the IMRC valve to set.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This diagnostic table will only diagnose the IMRC solenoid and the IMRC driver module. If there is a DTC set for the IMRC solenoid, refer to the appropriate DTC table.

    2.

  2. This step tests the IMRC driver module. The test lamp should turn ON and OFF when commanded with a scan tool. If the test lamp does not turn ON and OFF and there are no IMRC DTCs stored, replace the IMRC driver module.

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Turn ON the ignition, with the engine OFF.
  2. Observe the DTC information with a scan tool.

Is DTC P2008, P2009, or P2010 set?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

Go to Step 3

3
  1. Remove the intake manifold runner control (IMRC) solenoid from the intake manifold, but leave the electrical connector connected. Refer to Intake Manifold Runner Control Solenoid Replacement .
  2. Command the IMRC solenoid ON and OFF with a scan tool.
  3. Observe the valve of the IMRC solenoid while you command the IMRC solenoid ON and OFF.

Does the valve of the IMRC solenoid move in both directions?

--

Go to Step 4

Go to Step 5

4

    Important: Inspect the IMRC solenoid valve for witness marks that indicate that the valve was hitting the intake manifold. This condition may be temperature related.

  1. Inspect the inside of the intake manifold for the following conditions:
    2. • For carbon build-up that limits the movement of the IMRC valve
    • For casting flash that limits the movement of the IMRC valve
    • For foreign material that limits the movement of the IMRC valve
  2. Clean or replace the upper intake manifold. Refer to Upper Intake Manifold Replacement in Engine Mechanical - 3.6L (LY7).

Did you find and correct the condition?

--

Go to Step 8

Go to Diagnostic Aids

5

  1. Disconnect the IMRC solenoid connector.
  2. Connect a test lamp between the control circuit of the IMRC solenoid and the ignition 1 voltage circuit of the IMRC solenoid.
  3. Command the IMRC solenoid ON and OFF with a scan tool.

Does the test lamp turn ON and OFF as commanded?

--

Go to Step 6

Go to Step 7

6

Replace the IMRC solenoid. Refer to Intake Manifold Runner Control Solenoid Replacement .

Did you complete the replacement?

--

Go to Step 8

--

7

Replace the IMRC driver module. Refer to Intake Manifold Runner Control Module Replacement .

Did you complete the replacement?

--

Go to Step 8

--

8
  1. Connect all disconnected components.
  2. Clear the DTCs with a scan tool.
  3. Start the engine.
  4. Operate the system in order to verify the repair.

Did you correct the condition?

--

Go to Step 9

Go to Step 2

9

Observe the capture info with a scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

System OK