P2009

DTC P2009

CIRCUIT DESCRIPTION




The intake manifold upper plenum is divided into two separate runners by an intake manifold runner control (IMRC) valve. During low speed, high load conditions the IMRC valve is closed creating a longer runner path inside the plenum which increases torque. During higher engine speeds the IMRC valve opens creating a shorter runner path inside the plenum which increases horsepower. The IMRC valve is controlled by an IMRC vacuum solenoid. Manifold vacuum is supplied to the IMRC solenoid. A 12-volt supply from the manifold fuse to the IMRC solenoid is applied when the ignition key is turned ON. The solenoid is normally closed which will not allow vacuum to pass through it. When the engine speed and load are increased above a calibrated threshold, the engine control module (ECM) provides a ground to the solenoid, energizing the solenoid and allowing a vacuum to be applied to the IMRC valve. When the IMRC solenoid is commanded OFF, the voltage of the control circuit is high, battery voltage. When the IMRC solenoid is commanded ON, the voltage of the control circuit is low, near zero volts. The ECM applies a pull up voltage of 4.6-6.6 volts on the control circuit to differentiate between an open, a short to ground, or a short to voltage. If the ECM detects a feedback voltage that is less than what it should be when the IMRC solenoid is commanded OFF, DTC P2009 sets.

CONDITIONS FOR RUNNING THE DTC
- The engine speed is more than 40 RPM.
- The engine is cranking or running.
- The battery voltage is more than 7.5 volts and less than 15 volts.

CONDITIONS FOR SETTING THE DTC
The ECM detects that the IMRC solenoid feedback voltage is less than 4.6 volts when the IMRC solenoid is commanded OFF for more than 0.5 second.

ACTION TAKEN WHEN THE DTC SETS
- The control module stores the DTC information into memory when the diagnostic runs and fails.
- The malfunction indicator lamp (MIL) will not illuminate.
- The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
- The driver information center, if equipped, may display a message.

CONDITIONS FOR CLEARING THE DTC
- A current DTC Last Test Failed clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
- Clear the DTC with a scan tool.

TEST DESCRIPTION

Steps 1-12:

Step 13:

The numbers below refer to the step numbers on the diagnostic table.
4. Tests for voltage at the coil side of the IMRC solenoid. The manifold fuse supplies power to the coil side of the IMRC solenoid.
5. Verifies that the ECM is providing ground to the IMRC solenoid.