P2012 Intake Manifold Slider Control Circuit Bank 2 Low
Content
P2012 Intake Manifold Slider Control Circuit Bank 2 Low
OBD-II DTC Datasheet
Intake Manifold Impeller Control Circuit Bank 2 Signal Low
What does this mean?
This Diagnostic Trouble Code (DTC) is a generic transmission code, which means it applies to all 1996 vehicles (Nissan, Honda, Infiniti, Ford, Dodge, Acura, Toyota, etc.). Although general in nature, the specific repair steps may differ depending on the brand / model.
I know from experience that a stored code P2012 means that the powertrain control module (PCM) has detected an intake manifold control (IMRC) actuator circuit voltage (for engine bank 2) that is lower than expected. Bank 2 indicates to me a malfunction that is associated with an engine group that does not have a number one cylinder.
The IMRC system is electronically controlled by the PCM. It is used to control and fine tune the air to the lower intake manifold, cylinder heads and combustion chambers. A specially shaped metal flap that fits snugly into the intake manifold of each cylinder is opened and closed by an electronic travel control actuator. Thin metal rail baffles are attached (with small bolts or rivets) to a metal bar that extends the length of each cylinder head and runs through the center of each intake port. The flaps open in one motion, which allows you to disable all the flaps if one of them is stuck or stuck. A mechanical arm or gear usually attaches the IMRC actuator to the stem. Some models use a vacuum diaphragm to control the actuator. The PCM controls an electronic solenoid that regulates the suction vacuum to the IMRC actuator when a vacuum actuator is used.
Research has shown that the swirling (air flow) effect promotes more complete atomization of the fuel / air mixture. Closer atomization helps reduce exhaust emissions, improve fuel efficiency and optimize engine performance.
Directing and restricting the airflow as it is drawn into the engine creates this swirling effect, but different manufacturers use different IMRC methods. Refer to your vehicle information source (All Data DIY is a great resource) for details on the IMRC system that this vehicle is equipped with. Typically, IMRC runners are nearly closed during start/idle and are open most of the time when the throttle is open.
To ensure that the IMRC system is working properly, the PCM monitors data inputs from the IMRC impeller position sensor, manifold absolute pressure (MAP) sensor, manifold air temperature sensor, intake air temperature sensor, throttle position sensor, oxygen. sensors and mass air flow (MAF) sensor (among others).
The PCM monitors the actual position of the impeller flap and adjusts it according to the controllability data of the engine. The malfunction indicator lamp may illuminate and a P2012 code will be stored if the PCM does not see a significant change in MAP or manifold air temperature as expected. In some cases, it will take multiple failure cycles to illuminate the MIL.
symptoms
Symptoms of a P2012 code may include:
- Oscillation on acceleration
- Decreased engine performance, especially at low revs.
- Rich or lean exhaust
- Reduced fuel efficiency
- Engine surge
reasons
Possible causes of this engine code include:
- Loose or seized intake manifold rails, bank 2
- Faulty IMRC actuator solenoid bank 2
- Defective intake manifold chassis position sensor, bank 2
- Open or short circuit in the solenoid control circuit of the IMRC actuator
- Carbon build-up on IMRC flaps or intake manifold openings
- Defective MAP sensor
- Corroded surface of the IMRC actuator solenoid valve connector
Diagnostic and repair procedures
When trying to diagnose a P2012 code, a diagnostic scanner, digital volt / ohmmeter (DVOM), and a reliable source of vehicle information will be helpful. Before any diagnosis, it is recommended that you check the Technical Service Bulletins (TSB) for specific symptoms, stored codes, and vehicle make and model. If you find the appropriate TSB, this information will often help in diagnosing the code in question, as TSBs have come out of many thousands of repairs.
A great starting point for any diagnosis is a visual inspection of the system wiring and connector surfaces. Knowing that IMRC connectors are prone to corrosion and that this can cause an open circuit, you can focus on this area.
You can proceed by connecting the scanner to the vehicle's diagnostic connector and retrieving all stored codes and freeze frame data. It is good practice to record this information in case it is intermittent code. Now clear the codes and test drive the vehicle to make sure the code is cleared.
Continuing, I would have access to the IMRC actuator solenoid and the IMRC impeller position sensor if the code was cleared. Consult your vehicle information source for test specifications and use the DVOM to perform both solenoid and sensor resistance tests. If any of these components are out of specification, replace and retest the system.
To prevent damage to the PCM, disconnect all associated controllers before testing circuit resistance with the DVOM. Use the DVOM to test resistance and continuity on all circuits in the system if the drive and transducer resistance levels are within manufacturer's specifications. Shorted or open circuits will need to be repaired or replaced as needed.
Additional diagnostic notes:
- Carbon coking inside the intake manifold walls can lead to sticking of the IMRC flaps.
- Be careful when handling small screws or rivets in or around the intake manifold openings.
- Check for jamming of the IMR damper with the drive disconnected from the shaft.
- The screws (or rivets) that secure the flaps to the shaft can loosen or fall out, causing the flaps to seize.
Related DTC discussions
- There are currently no related topics in our forums. Post a new topic on the forum now.
Need more help with the P2012 code?
If you still need help with DTC P2012, post a question in the comments below this article.
NOTE. This information is provided for informational purposes only. It is not intended to be used as a repair recommendation and we are not responsible for any action you take on any vehicle. All information on this site is protected by copyright.
