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 directly 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. If the ECM detects the control circuit voltage is within a predetermined range when the circuit is commanded OFF, this DTC sets.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P2008 Intake Manifold Runner Control (IMRC) Solenoid Control Circuit
Conditions for Running the DTC
| • | The engine speed is more than 80 RPM. |
| • | The ignition 1 voltage is between 10-18 volts. |
| • | The ECM has commanded the IMRC solenoid ON and OFF at least once during the ignition cycle. |
| • | DTC P2008 runs continuously once the above conditions are met. |
Conditions for Setting the DTC
| • | The ECM detects the control circuit voltage for the IMRC solenoid is between 2.6-4.6 volts when the driver is commanded OFF. |
| • | The condition exists for less than 1 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. |
Diagnostic Aids
| • | Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector. |
| • | The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to Engine Controls Component Views . |
| • | If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the circuit status for the component with a scan tool. The circuit status parameter changes from OK or Indeterminate to Fault if there is a condition with the circuit or a connection. The output driver module (ODM) information is in the ODM data list. |
| • | For an intermittent condition, refer to Intermittent Conditions . |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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Listen for an audible click when the IMRC solenoid operates. Command both the ON and OFF states. Repeat the commands as necessary.
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This step tests the ignition 1 voltage circuit to the IMRC solenoid.
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This step tests the control modules ability to supply a ground to the IMRC solenoid.
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This step tests the feedback voltage from the ECM. If a voltage is not available, this indicates an internal ECM condition.
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-Engine Controls? | -- | Go to Step 2 | |
Does the DTC fail this ignition? | -- | Go to Step 4 | Go to Step 3 | |
3 |
Did the DTC fail this ignition? | -- | Go to Step 4 | Go to Diagnostic Aids |
Does the test lamp illuminate? | -- | Go to Step 5 | Go to Step 10 | |
Important: The IMRC Command parameter may not change from OFF to ON or ON to OFF when using the IMRC output control. Does the test lamp turn ON and OFF? | -- | Go to Step 6 | Go to Step 7 | |
Measure the voltage from the control circuit of the IMRC solenoid to the ECM housing with a DMM. Is the voltage within the specified range? | 2.6-4.6 V | Go to Step 8 | Go to Step 12 | |
7 | Test the control circuit of the IMRC solenoid for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 9 |
8 | Test for an intermittent and for a poor connection at the IMRC solenoid. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 11 |
9 | Test for an intermittent and for a poor connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 12 |
10 |
Did you complete the repair? | -- | Go to Step 13 | -- |
11 | Replace the IMRC solenoid. Refer to Intake Manifold Runner Control Solenoid Replacement . Did you complete the replacement? | -- | Go to Step 13 | -- |
12 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | -- | Go to Step 13 | -- |
13 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 14 |
14 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |
