How severe is this DTC?
The severity of this code can vary significantly from moderate to severe depending on the specific symptoms of the malfunction. Several symptoms of this fault code can make driving the vehicle extremely dangerous.
What are some of the symptoms of the code?
Symptoms of a P2438 fault code may include:
- Engine may stall at idle
- Engine may not start
- Noisy secondary air injection system
- Poor engine performance
- Check engine light illuminated
What are some common causes of the code?
Causes
of this P2438 code may include:
- Faulty secondary air injection pump
- Faulty one-way check valve
- Faulty air control solenoid valve
- Faulty air pressure sensor
- Faulty or damaged wiring
- Corroded, damaged, or loose connector
- Faulty PCM
What are the troubleshooting steps for P2438?
The first step in troubleshooting any malfunction is to search for Technical Service Bulletins (TSBs) for the specific vehicle by year, model, and powertrain. In some circumstances, this can save you significant time in the long run by pointing you in the right direction.
Depending on the specific vehicle, this circuit may incorporate several components, including the secondary air injection pump, check valve, pressure sensor, air control valve, and PCM. Perform a thorough visual inspection to check that the associated wiring shows no obvious defects such as scraping, rubbing, bare wires, or burns. Then, check the connectors and connections for security, corrosion, and damaged pins. This process should include all wiring connectors and connections to all components, including the PCM. Consult vehicle-specific technical data to verify the circuit configuration and confirm each component incorporated into the circuit, which may include a fuse or fusible link. The check valve must be tested to ensure airflow is in one direction only. Ice in the secondary air injection pump during extremely cold weather indicates a faulty one-way check valve allowing exhaust condensation to enter the pump.
Advanced Steps
Advanced steps become very vehicle-specific and require appropriate advanced equipment to perform accurately. These procedures require a digital multimeter and vehicle-specific technical references.
Voltage Checks
Reference voltage and acceptable ranges may vary depending on the specific vehicle and circuit configuration. Specific technical data will include troubleshooting charts and the proper sequence to follow to help you make an accurate diagnosis.
If this process identifies a missing power source or ground, continuity tests may be required to verify the integrity of the wiring, connectors, and other components. Continuity tests should always be performed with the power disconnected from the circuit, and normal readings for wiring and connections should be 0 ohms of resistance. Resistance or lack of continuity indicates faulty wiring that is open, shorted, or corroded and must be repaired or replaced.
What are the common repairs for this code?
- Replacement of the secondary air injection pump
- Replacement of the faulty one-way check valve
- Replacement of the air pressure sensor
- Replacement of the air control solenoid valve
- Cleaning corrosion from connectors
- Repairing or replacing faulty wiring
- PCM replacement
Common Mistake
Replacing the secondary air injection pump when a faulty one-way check valve or faulty wiring is causing the PCM to set this code.
I hope the information in this article has helped point you in the right direction to correct the issue with the Bank 2 Sensor Circuit Flow/Pressure fault code for the secondary air injection circuit. This article is strictly informational, and your vehicle’s specific technical data and service bulletins should always take priority.