How do you fix a intake plenum switchover valve circuit

Question edited for clarity.
Question moved to model category.

It is the intake manifold tuning valve that is stuck and fortunately not the Inlet valve itself.

https://www.google.com/search?q=2008+Chevy+Uplander+P2070

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What year is it ?
DTC P2078: Intake Manifold Tuning (IMT) Valve Position Sensor Circuit High Voltage
Associated with this code or any coded is a diagnostic flow chart ,for testing of the electrical circuit's for the position sensor . If you don't know that ,an know how to test electrical circuit's ,your best bet , take it to a qualified repair . Rather then guessing an just replacing parts .

Circuit/System Description
An intake manifold tuning (IMT) valve is used to change the intake manifold plenum configuration. When the IMT valve is open, the intake manifold is configured to one large plenum. When the IMT valve is closed, the intake manifold is configured to 2 smaller plenums. The IMT valve improves engine performance at low and high engine speeds depending on the engine load. The IMT valve assembly consists of the following:
• A tuning valve
• A microprocessor
• An electric motor
• A hall-effect sensor
• An ignition voltage circuit
• A ground circuit
• An IMT valve control circuit
• An IMT valve signal circuit

P2078
The engine control module detects an open in the IMT valve ground or a continuous short to voltage in either the IMT valve signal circuit or the sensor. This diagnostic runs continuous when the conditions for running are met.
Test the electrical circuit's !!!!!!! you would need a wiring diagram

Circuit/System Testing
Ignition OFF, disconnect the IMT valve harness connector at the IMT valve.
Test for less than 1 ohm of resistance between the IMT valve ground circuit terminal B and ground.
? If greater than the specified value, test the ground circuit for an open/high resistance.
Ignition ON, verify that a test lamp illuminates between the IMT valve ignition 1 voltage circuit terminal A and ground.
? If the test lamp does not illuminate, test the IMT valve ignition 1 voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the fuse for the IMT valve ignition 1 voltage circuit is open, test or replace the IMT valve.
Connect a test lamp between the IMT valve control circuit terminal C and the IMT valve ignition 1 voltage circuit terminal A.
Command the IMT valve ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
? If the test lamp is always ON, test the IMT valve control circuit for a short to ground. If the circuit tests normal, replace the engine control module.
? If the test lamp is always OFF, test the IMT valve control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the engine control module.
Ignition ON, test for 4-6 volts between the IMT valve signal circuit terminal D and ground.
? If less than the specified range, test the IMT valve signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the engine control module.
? If greater than the specified range, test the IMT valve signal circuit for a short to voltage. If the circuit tests normal, replace the engine control module.
Install a 3A fused jumper wire between the IMT valve signal circuit terminal D and ground. Verify the scan tool IMT valve Feedback parameter transitions from 0-100 percent.
? If parameter does not change, test the IMT valve signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the engine control module.
If all circuits test normal, test or replace the IMT valve.

The code P1245 is for the Intake Plenum Switchover Valve.

This probably has nothing to do with the gauge fluctuations. The gauge problem is probably one of three possibilities:

1. Low coolant level in the system. When coolant levels get low, air moves thru the system and when it reaches the temp sensor, will cause fluctuations.
2. Defective coolant sensor. These can fail over time as do all sensors.
3. Defective gauge in the dashboard.

I don't know what it means:

P1113 Intake Resonance Switchover Valve Circuit

Oldsmobile Check Engine Light Codes Welcome to the Oldsmobile Check Engine...

P1112: intake plenum switchover valve control.
P1740:Torque management request circuit.
P0115:ECT sensor circuit.
P50501: NO informations, mabe

Big breather from valve cover to air cleaner, the small vac line runs from there to the FPR.



These next are standing in front of the car:

Intake manifold lower outer runs to EZL

Intake manifold lower inner (right side) goes to switchover vac valve on driver fender. The other side of this vac valve goes to the throttle body

Intake manifold lower inner (left side) goes to switchover vac valves on passenger side fender. These then go back to the EGR valve once making a loop under the distributor cap for whatever reason.

Intake manifold rear runs to a 'three' way valve (or 'Y' connector) on the secondary firewall. This is usually a vac leak.

p1227 Oldsmobile Injector 2 Control Circuit Shorted
p1245 Oldsmobile Intake Plenum Switchover Valve
p1275 Oldsmobile Accelerator Pedal Positioning (APP) Sensor 1 Circuit p0300 Oldsmobile Multiple Engine Misfire Detected p0172 Oldsmobile Fuel Trim System Rich (Bank 1)
sounds like bad injectors for one and computer needs relearned or replaced unfortuantly u gotta goto to the dealer have diagnostics ran

P1004 - SHORT RUNNER VALVE CONTROL PERFORMANCE

Sound like something came loose. If you cannot find it you need to take it to the dealer so they can perform these diagnostics. Should be under warranty.

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 and ambient temperature, 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 (SRV) control active.
* Set Condition: The Powertrain Control Module (PCM) compares the circuit feedback to a calibrated closed range, between 75% & 85% Pulse Width Modulated (PWM) duty cycle, when the circuit is de-energized or to a calibrated open range, between 35% & 55% PWM duty cycle, when the circuit is energized. If the value is determined to be out of the calibrated range in either the de-energized, greater than 85% duty cycle or less than 75% duty cycle, or energized, greater than 55% duty cycle or less than 35% duty cycle, state for more than a calibrated amount of time, this DTC will set.

Possible Causes
(F344) ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE
(K237) SHORT RUNNER VALVE (SRV) SIGNAL CIRCUIT SHORTED TO GROUND
(K237) SHORT RUNNER VALVE (SRV) SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE
(K238) SHORT RUNNER VALVE (SRV) CONTROL CIRCUIT SHORTED TO GROUND
(K238) SHORT RUNNER VALVE (SRV) CONTROL CIRCUIT OPEN OR HIGH RESISTANCE SHORT RUNNER VALVE (SRV) ASSEMBLY


Hope this helps (remember to rate and comment this answer).

never hear of such a thing. it does not exist on that engine period

The best way to remove the rear valve cover is to remove the intake plenum. There is really no other way to do it. It is not a hard job, removing the intake plenum, but, trying to tackle the rear cover without taking off the plenum is almost impossible. If he does remove the plenum, make sure he replaces the plenum gasket. Hope this helps.
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