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    P200A Intake Manifold Runner Performance Bank 1

    What does this OBD II code mean? 

    This generic OBD2 code is set when the Powertrain Control Module (PCM) detects that the Intake Manifold Runner Control (IMRC) performance is outside the acceptable parameters. This particular code is pointing out the bank 1, in other words, the bank of cylinders containing cylinder #1.


    Why does this OBD II code appear?

    The Intake Manifold Runner Control (IMRC) is a system in charge of controlling the intake manifold variable airflow. Depending on the OEM, this system can vary the length of intake ports (from short to long) or simply regulate the airflow turbulence using a flap design similar to the throttle body. The goal of IMRC is prioritizing torque or power at any given operational condition. At lower RPM the IMRC helps the engine to achieve more torque, as you may infer, at higher RPM the IMRC operates in order to increase the engine power. Using this technology the manufacturers can also boost fuel economy and decrease the exhaust emissions. Some IMRC systems discriminate engine banks because they operate each one independently of the other. In order to achieve peak performance, the PCM uses information from many of its sensors. including but not limited to engine speed sensor, throttle position sensor, the throttle pedal position sensor (if applicable), and in some cases, the engine coolant. The sensors’ data allows the PCM  modulating the IMRC actuators under different conditions as well as determining its performance.
    The OBD2 code P200A is set when the PCM senses that the intake manifold runner control is not performing as expected. 


    What symptoms may occur with this OBD II code?

    The following symptoms could be present:

    • CEL lit. The Check Engine Light will turn on after few driving cycles to alert the driver about the situation. 
    • Expect reduced engine power/torque depending on IMRC position (in case it got stuck).
    • Also, expect a variation in fuel economy depending on IMRC condition.
    • Engine lags under wide open throttle situations are very common.
    • Some engine technologies may be susceptible to IMRC failures and cause rough idle, gasoline smell in the exhaust tail and even some emission related codes.


    What are the causes that trigger this OBD II code?

    There're many factors that could trigger this code including among others the following:

    • Damaged, burnt, corroded, open or shorted IMRC wiring. 
    • Worn, corroded, burnt, disconnected or bent IMRC wiring harness connector pins. 
    • Air leaks in the intake manifold, PCV hose, vacuum hoses, vacuum driven components or MAF sensor tubing.
    • Faulty, worn, corroded, broken or bent IMRC linkage. The majority of IMRC systems use metal flaps (similar to throttle body flap) that are linked together to control the whole bank. It’s common to find wear or corrosion in the mechanical components, especially in hot or high humidity climates.
    • Damaged, worn, corroded or broken IMRC bushing. The normal mechanical wear produced by the constant usage of this system could cause the mechanism to “get stuck” or “partially stuck”. Think of it as the “mechanical resistance to movement” that will make very difficult to comply with PCM orders
    • Faulty or deficient IMRC actuator (electrical or vacuum operated). The IMRC actuator is usually electro-mechanical (a servo motor electronically controlled by the PCM similar to ETC) or vacuum controlled. Either design, it’s susceptible to failure as any other moving part in the engine.
    • Even when unlikely, a defective PCM cannot be discarded.

    Diagnostic strategy for troubleshooting this OBD II code

    It's highly recommended starting the diagnostic process with the usual information gathering:

    • With the help of a professional OBD2 scan tool, preferably one with OEM capabilities, take note of all data trouble codes in memory, including pending codes.
    • Take note of freeze frame information (if present).
    • Query the vehicle owner about what, when and where the failure occurs. Does it happen with the engine hot? Cold? Under load? All the standard questions.
    • Take note of the vehicle VIN and find a reliable source of technical reference.

    Once you are done, the next step is discarding an intermittent condition. 

    • Using your scan tool clear DTC memory. 
    • Perform a complete driving cycle according to OEM procedures.

    If the code P200A disappears then inform the owner about the intermittent nature of the code and explain that further testing with the code present will be required. If the code does appear then continue to the testing stage, consisting in discarding the possible causes of the problem. 

    IMPORTANT: the diagnostic procedure explained in this section should be taken as a guideline. Always refer to specific OEM procedures when possible.

    The workflow for the diagnostic process is:

    • The tests should be executed in sequential order, in other words, complete step 1 before going to step 2 and so on.
    • Repair, fix, or replace any component if you suspect is not in good condition.
    • If any repair, fix, reprogramming or component replacement is made during any step then you should clear DTC memory and repeat the whole KOER driving cycle.
    • If the DTC appear again then you should continue to the next step.
    • If the DTC does not appear again after completing the KOER tests then you can assume the problem is fixed, in that case, continuing with the remaining steps would be optional.

    The diagnostic process for the code P200A is as follows:

    1. IMRC harness wiring and connector: carry out an exhaustive visual inspection of IMRC wiring and connectors. Pay special attention to burnt, corroded or deteriorated wiring and/or connector. Unplug the actuator and check for corrosion, damage, bent pins, etc.
    2. Electrical tests: with the help of a digital volt-ohm meter (DVOM) and the adequate wiring diagram perform a KOEO check of the IMRC. Verify supply and/or reference voltage, electrical resistance, continuity, current and ground integrity. Compare the obtained values with the appropriate OEM literature.
    3. Vacuum and/or air leaks: perform a manual vacuum reading in the intake manifold test port or in any direct vacuum hose with no direct relation to the fuel injection system. If the vacuum reading is not within the normal value then perform a comprehensive visual inspection of all vacuum hoses including but not limited to PCV hose, fuel pressure regulator hose, MAP hose, brakes hose, etc, also look for intake manifold leaks and pay special attention to possible air or vacuum leaks downstream the MAF sensor. Also, check PCV and replace if defective. 
    4. IMRC functional test: with the help of a professional OBD2 scan tool carry out an actuator test (sometimes called functional test). This test allows you to operate the IMRC system, depending on the vehicle year and manufacturer the test requires an engine running (KOER) condition or key on engine off (KOEO) condition. During the test pay special attention to any suspicious sound as a possible indication of internal wear.
    5. IMRC functional test (vacuum controlled): if the system is vacuum operated then check all associated vacuum lines and check valves. Using a manual vacuum pump check the actuator operation.
    6. Problems with the powertrain control module: the most unlikely cause for this code is a faulty PCM or a corrupted program. Yet, if you are completely certain that all prior tests passed then you must remove the PCM and check it, reprogram it or replace it as necessary.
       

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