P2008
P2008-SHORT RUNNER VALVE (SRV) CONTROL CIRCUIT
For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
The engine performance and power output is enhanced through the use of the "Short Runner Valve" (SRV) system. The SRV system allows the intake charge air to bypass the long intake manifold runners between the intake manifold plenum and the intake manifold interface to the cylinder heads by providing a shorter runner directly between the plenum and the cylinder head interface The SRV position is controlled by a pneumatic/spring actuator and electronic solenoid valve. When the solenoid is not energized (the "rest" position), the SRV is held in the closed position. When the solenoid is energized the SRV is moved and held in its opened position. There is a set of enable conditions including a minimum Engine Coolant Temperature (ECT) and Ambient Air Temperature (AAT), SRV enable and Powertrain Coordinator load enable condition. If any of these conditions are not met, then the SRV valve is de-energized (closed).
- When Monitored:
With the engine run time above a calibrated value, battery voltage greater than 10.4 Volts, ECT within a specific range and the Short Runner Valve Assembly control active.
- Set Condition:
This Powertrain Control Module (PCM) compares the circuit feedback to a calibrated closed range when the circuit is de-energized or to a calibrated open range when the circuit is energized. If the value is determined to be out of the calibrated range in either the de-energized or energized state for more than a calibrated amount of time, this DTC will set.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.
1. DTC IS ACTIVE
1. Turn the ignition on.
2. With the scan tool, Clear DTCs in the Powertrain Control Module (PCM).
3. With the scan tool, actuate the SRV Solenoid Control State.
4. With the scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.
2. (F344) ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Short Runner Valve Assembly harness connector.
3. Turn the ignition on.
4. With the scan tool, actuate the Auto Shutdown (ASD) Relay Control State.
5. Using a 12-volt test light connected to ground, check the (F344) ASD Relay Output circuit in the Short Runner Valve Assembly harness connector.
NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
Is the test light illuminated and bright?
Yes
- Go To 3
No
- Repair the (F344) ASD Relay Output circuit for an open circuit or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
3. (Z908) SRV GROUND CIRCUIT OPEN CIRCUIT OR HIGH RESISTANCE
1. Turn the ignition off.
2. Measure the resistance of the (Z908) SRV ground circuit in the Short Runner Valve Assembly harness connector to ground.
Is the resistance less than 5.0 Ohms?
Yes
- Go To 4
No
- Repair the (Z908) SRV ground circuit for an open circuit or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
4. SHORT RUNNER VALVE ASSEMBLY
1. Turn the ignition on.
2. With the scan tool, actuate the SRV Solenoid Control State to toggle.
3. Using a 12-volt test light connected to ground, check the (K238) SRV Control circuit in the Short Runner Valve Assembly harness connector.
NOTE: If the DTC is active, the actuation test may not be allowed by the PCM. If may be necessary to clear the DTCs before starting the actuation.
NOTE: The test light should illuminate on and off with the actuation.
Does the test light illuminate on and off with the actuation?
Yes
- Replace the Short Runner Valve Assembly.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 5
5. (K238) SRV CONTROL CIRCUIT SHORTED TO GROUND
1. Turn the ignition off.
2. Disconnect the Powertrain Control Module (PCM) C1 harness connector.
3. Measure the resistance between ground and the (K238) SRV Control circuit in the Short Runner Valve Assembly harness connector.
Is the resistance less than 100 Ohms?
Yes
- Repair the (K238) SRV Control circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 6
6. (K238) SRV CONTROL CIRCUIT OPEN OR HIGH RESISTANCE
CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install the PCM Pinout Box 8815 to perform diagnosis.
1. Measure the resistance of the (K238) SRV Control circuit between the Short Runner Valve Assembly harness connector and the appropriate terminal of PCM Pinout Box 8815.
Is the resistance less than 5.0 Ohms?
Yes
- Go To 7
No
- Repair the (K238) SRV Control circuit for an open circuit or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
7. (K238) SRV SIGNAL CIRCUIT SHORTED TO VOLTAGE
1. Turn the ignition on
2. Measure the voltage of the (K238) SRV Signal circuit in the Short Runner Valve Assembly harness connector.
Is there any voltage present?
Yes
- Repair the (K238) SRV Signal circuit for a short to voltage.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 8
8. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Short Runner Valve Assembly and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Perform any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Replace and program the Powertrain Control Module (PCM).
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.