Technical Description of OBD-II Trouble Code
The circuit range/performance of the Intake Manifold Runner Position Sensor/Switch in Bank 2
What does that signify?
This generic trouble code is applicable to fuel injected engines from various manufacturers since 2003.
These manufacturers include Ford, Dodge, Toyota, Mercedes, Volkswagen, Nissan, and Infiniti.
This code primarily focuses on the value provided by the intake manifold flow control valve/position sensor, also known as the IMRC valve/sensor. It is typically located at one end of the intake manifold and assists the vehicle’s PCM in regulating the amount of air entering the engine at different RPMs. This code specifically pertains to Bank 2, which consists of cylinders excluding cylinder number 1. The issue can be either a mechanical or electrical circuit fault, depending on the vehicle manufacturer and fuel system.
The troubleshooting steps may vary depending on the manufacturer, type of fuel system, and the type of intake manifold runner control valve/position sensor (IMRC) and wire colors.
Symptoms
The symptoms associated with a P2020 engine code may include:
Causes
The typical causes for this code to be triggered are:
(programming required after replacement)
Diagnostic Steps and Repair Information
A good starting point is to check for technical service bulletins (TSB) specific to your vehicle. There may be a known issue with a known fix provided by the manufacturer, which can save time and money during diagnosis.
The next step is to check for any other diagnostic fault codes. If there are any codes related to the intake/engine performance system, they should be diagnosed and repaired first. Misdiagnosis of these codes can occur if the P2020 code is diagnosed before thoroughly addressing any intake/engine performance related system codes. It is important to ensure that there are no intake or exhaust leaks, as an intake leak or vacuum leak can cause the engine to run lean, while an exhaust leak can create the impression of a lean running engine by affecting the air fuel ratio/oxygen (AFR/O2) sensor.
Once the above steps have been completed, locate the bank 2 IMRC valve/sensor in your specific vehicle. Inspect the connectors and wiring for any signs of rubbing, scraping, bare wires, worn spots, or melted plastic connectors. Separate the connectors and examine the terminals inside for any signs of burning or corrosion. If necessary, clean the terminals using Electrical Contact cleaner or rubbing alcohol and a small plastic bristle brush. After cleaning, allow them to air dry and apply dielectric silicone compound to the connector cavity before reassembling.
If you have a scan tool, clear the diagnostic trouble codes from memory and check if the code returns. If it does not, the issue was likely related to the connections.
If the code does return, it is necessary to test the voltage signals to and from the IMRC valve/sensor using a scan tool or a digital volt ohm meter (DVOM). With the sensor connected, monitor the IMRC sensor voltage or test the signal wire with the DVOM. As the engine RPM increases, the IMRC sensor signal should change. Refer to the manufacturer’s specifications for the expected voltage at a given RPM.
If the IMRC sensor fails this test, it is important to verify that the IMRC valve is not binding or sticking inside the intake manifold. Remove the IMRC sensor/actuator and check for any binding or looseness in the plates/valves inside the intake manifold. If there is any binding or looseness, the plates/valves and possibly the entire intake manifold may need to be replaced. It is recommended to seek professional assistance for this task.
If the IMRC plates/valves turn without any binding or excessive looseness, it indicates the need to replace the IMRC sensor/actuator and retest.
Once again, it is crucial to diagnose any other codes before addressing this one, as issues that trigger other codes can also trigger the P2020 code. It is also advisable to consult an automotive professional for the repair of your vehicle, as most repairs beyond the initial diagnosis require the removal and replacement of the intake manifold to properly address this code and the related engine performance issue.
Additionally, it is important to note that some IMRC plates/valves may be integrated with the sensor/actuator assembly and cannot be replaced separately. Attempting to disassemble them may result in breakage. If you are unsure about your vehicle, please consult an automotive professional.
