How Serious Is This DTC?
Stored IMRC codes will typically result in open intake manifold runner control flaps. The P200A should not be classified as severe but should be addressed as soon as possible.
What Are Some of the Symptoms of the Code?
Symptoms of a P200B fault code may include:
- Reduced fuel efficiency
- Decreased engine performance
- Lean or rich exhaust codes stored
- Hesitation during acceleration
- Rough idling
What Are Some Common Causes of the Code?
Causes of this code may include:
- Broken or worn IMRC linkage or bushings
- Faulty IMRC actuator
- Cracked or collapsed IMRC vacuum lines
- Defective IMRC vacuum supply actuator
- Open or shorted IMRC circuits or connectors
- Faulty IMRC sensor or other engine sensor(s)
What Are the Troubleshooting Steps for P200B?
If mass airflow (MAF), manifold absolute pressure (MAP), or intake air temperature (IAT) codes are stored, they should be addressed before attempting to diagnose the stored P200B.
If you can find a technical service bulletin (TSB) that matches the vehicle’s year, make, and model, as well as the engine size, stored codes, and presented symptoms, it may provide useful diagnostic information. A diagnostic scanner, digital volt/ohmmeter (DVOM), hand vacuum pump, and vehicle-specific diagnostic information source will be needed to diagnose a P200B code.
I prefer to start my diagnosis with a visual inspection of the IMRC system. I focus on mechanical linkages, vacuum lines and hoses, as well as wiring harnesses and electrical connectors. Worn or damaged hardware, bushings, or IMRC linkage should be repaired or replaced before proceeding.
I would proceed by locating the vehicle’s diagnostic connector, connecting the scanner, and retrieving all stored codes and relevant freeze frame data. It’s a good idea to record this information before clearing the codes, in case the code proves to be intermittent. Once this is done, test-drive the vehicle until the PCM enters readiness mode or the code resets. If the code is intermittent, it will be much more difficult to diagnose if the PCM enters readiness mode. At this point, the conditions that led to the code being stored may need to worsen before an accurate diagnosis can be made.
Component testing procedures (and specifications), diagnostic flowcharts, connector pinout diagrams, and connector face views will be needed to complete the next stage of your diagnosis.
With the key on and engine off (KOEO), use the vacuum pump to actuate the IMRC system for the relevant engine bank. Once vacuum pressure is applied to the IMRC actuator, verify that the flaps open on demand. If they do, observe the scanner data to see if the IMRC sensors (if applicable) are functioning correctly. If discrepancies are detected, test the respective sensor(s) using the DVOM. Suspect sensors that do not meet manufacturer specifications as faulty.
If all sensors and circuits appear to be functioning as expected and the IMRC hardware is intact, use the DVOM to test the appropriate circuit’s control channel solenoid(s). Actuator solenoids that do not meet manufacturer specifications should be considered defective.
Suspect PCM failure or a programming error only after all other possibilities have been exhausted.