P2437 Secondary Air Injection System Air Flow/Pressure Sensor Circuit Low Bank 2
OBD-II Trouble Code Technical Description
Secondary Air Injection System Air Flow/Pressure Sensor Circuit Low Bank 2
What does that mean?
This is a generic powertrain diagnostic trouble code (DTC) and applies to many OBD-II vehicles (1996-newer). That may include but is not limited to vehicles from Buick, Chevrolet, Cadillac, Lexus, Toyota, BMW, Subaru, etc. Although generic, the exact repair steps may vary depending on year, make, model and powertrain configuration.
OBD-II trouble code P2437 and related codes P2435, P2436, P2438, and P2439 are associated with the secondary air injection system air flow/pressure sensor circuit bank 2. Bank 2 is the side of the engine that does not contain cylinder #1.
The purpose of the secondary air injection system air flow/pressure sensor circuit bank 2 is to reduce the amount of hydrocarbon exhaust emissions during engine start-up when the weather conditions are cold. The Power Control Module (PCM) activates the air pump to supply pressurized fresh air to accelerate the catalyst operation reducing the level of harmful exhaust gas. This process also allows the engine to reach the normal operating temperature faster. The air system pressure sensor is used to monitor pressure at the air control solenoid valve inlet to open and close the valve at predetermined temperatures and pressures based on the manufacturers’ recommendations.
When the PCM detects voltage or resistance within the secondary air injection system air flow/pressure sensor circuit bank 2, that is too low, below the normal range threshold, code P2437 will be set and the check engine light may be illuminated.
Secondary air injection components:
What is the severity of this DTC?
The severity of this code can vary tremendously from moderate to severe depending on the specific symptoms of the malfunction. Several symptoms of this trouble code could make driving the vehicle extremely hazardous.
What are some of the symptoms of the code?
Symptoms of a P2437 trouble code may include:
What are some of the common causes of the code?
Causes for this P2437 code may include:
What are some P2437 troubleshooting steps?
The first step in the troubleshooting process for any malfunction is to research the Technical Service Bulletins (TSB’s) for the specific vehicle by year, model and power plant. In some circumstances, this can save a lot of time in the long run by pointing you in the right direction.
Based on the specific vehicle, this circuit may incorporate several components including the secondary air injection pump, check valve, pressure sensor, air control valve and the PCM. Perform a thorough visual inspection to check the associated wiring for obvious defects such as scraping, rubbing, bare wires, or burn spots. Next is to check the connectors and connections for security, corrosion and damaged pins. This process must include all wiring connectors and connections to all components including the PCM. Consult the specific tech data for the vehicle to verify the configuration of the circuit and confirm every component incorporated within the circuit which may include a fuse or a fuse-able link. The check valve should be tested to ensure that the airflow is in one direction only. Ice in the secondary air injection pump during extremely cold weather conditions is an indication of a defective one-way check valve allowing condensation from the exhaust to enter the pump.
Advanced Steps
The advanced steps become very vehicle specific and require the appropriate advanced equipment to perform accurately. These procedures require a digital multi meter and the specific technical references for the vehicle.
Voltage Checks
The reference voltage and the acceptable ranges may vary based on the specific vehicle and the circuit configuration. Specific technical data will include troubleshooting charts and the appropriate sequence to follow assisting you with an accurate diagnosis.
If this process identifies the absence of a power source or ground, continuity testing may be required to check the integrity of the wiring, connectors and other components. Continuity tests should always be performed with the power removed from the circuit and the normal readings for wiring and connections should be 0 ohms of resistance. Resistance or no continuity is an indication of faulty wiring that is open, shorted or corroded and must be repaired or replaced.
What are some common repairs for this code?
Common Mistake
Hopefully, the information in this article has been helpful to point you in the right direction to correct the problem with your secondary air injection system air flow/pressure sensor circuit bank 2 fault code. This article is strictly informational and the specific technical data and service bulletins for your vehicle should always take priority.
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Let us fix your problem. You are most welcome our diagnosis experts have in most cases the knowledge and skills to find the cause of the error code p2437 and to solve the problems.
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"Delete Error Code Permanently, Disable DTC Error Code Function for p2437 in the ECU"
In extreme cases, we even have the option to permanently remove the specific DTC p2437 and disable the function of the specific error code in the ECU. All other fault code functions will then continue to work to protect the engine. This is different from clearing an error code with a diagnostic device. We have the option to permanently remove the function of the specific error code, so that it never comes back. Also emergency running that occurs on the specific error code can be solved in most cases.
Of course we prefer to first try to solve the cause of the error code, but sometimes the only solution is to permanently disable the DTC function of p2437.
