P2020 Intake Manifold Runner Position Sensor / Switch Circuit Range Perf Bank 2
OBD-II Trouble Code Technical Description
Intake Manifold Runner Position Sensor / Switch Circuit Range/Performance Bank 2
What does that mean?
This generic powertrain/engine diagnostic trouble code typically applies to fuel injected engines from most manufacturers since 2003.
Those manufacturers include but are not limited to Ford, Dodge, Toyota, Mercedes, Volkswagen, Nissan and Infiniti.
This code is mostly concerned about the value provided by the intake manifold flow control valve/position sensor, also called known as a IMRC valve/sensor (typically located at one end of the intake manifold) which helps the vehicle’s PCM control the amount of air being allowed into the engine at various RPMs. This code is set for Bank 2, which is the bank of cylinders that does not include cylinder number 1. This can be a mechanical or an electrical circuit fault, depending upon vehicle manufacturer and fuel system.
Troubleshooting steps may vary depending upon manufacturer, type of fuel system and the type of intake manifold runner control valve/position (IMRC) sensor and wire colors.
Symptoms
Symptoms of a P2020 engine code may include:
Malfunction Indicator Lamp (MIL) illuminated Lack of power Occasional misfire Poor fuel economyCauses
Typically, the causes for this code to set are:
Sticking/faulty throttle plates/body Sticking/faulty IMRC valve bank 2 Faulty IMRC actuator/sensor bank 2 Rarely - faulty Powertrain Control Module (PCM)(programming required after replacement)
Diagnostic Steps and Repair Information
A good starting point is always to check for technical service bulletins (TSB) for your particular vehicle. Your issue may be a known issue with a known fix put out by the manufacturer and can save you time and money during diagnosis.
The next thing you should do is notice if there are any other diagnostic fault codes. If any of them are intake/engine performance system related, diagnose them first. Misdiagnosis of these codes has been known to occur if someone diagnoses this code before any intake/engine performance related system codes have been thoroughly diagnosed and repaired. Make sure there are no intake or exhaust leaks. An intake leak, or vacuum leak, makes the engine run lean. An exhaust leak gives the impression of a lean running engine by pulling air past the air fuel ratio/oxygen (AFR/O2) sensor.
Next, locate the bank 2 IMRC valve/sensor on your particular vehicle. Once located, visually inspect the connectors and wiring. Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors. Pull the connectors apart and carefully look at the terminals (the metal parts) inside the connectors. Check to make sure they are not burnt or corroded. If in doubt, get some Electrical Contact cleaner at any parts store if cleaning of the terminals is needed. If not possible, get some rubbing alcohol and a small plastic bristle brush to clean them. Once cleaned, let them air dry. Pack the connector cavity with dielectric silicone compound (same stuff they use for light bulb sockets and spark plug wires) and reassemble.
If you have a scan tool, clear the diagnostic trouble codes from memory, and see if this code returns. If it does not, then the connections were most likely your problem.
If the code does return, we will need to test the IMRC valve/sensor voltage signals to and from the PCM. Monitor IMRC sensor voltage on your scan tool. If a scan tool is not available, then test the signal coming from the IMRC sensor with a digital volt ohm meter (DVOM). With the sensor connected, the red voltmeter lead should be attached to the IMRC sensor signal wire and the black voltmeter lead connected to ground. Start the engine and monitor the IMRC sensor input. Snap the throttle.
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