P2259 Secondary Air Injection System Control B Circuit Low
OBD-II Trouble Code Technical Description
ASE Certified Technician
Secondary Air Injection System Control B Circuit Low
What does P2259 mean?
总裁俱乐部appThis diagnostic trouble code (DTC) is a generic powertrain code and applies to many OBD-II vehicles (1996-newer). That may include but is not limited to vehicles from Mazda, BMW, Ford, Dodge, Saab, Range Rover, Jaguar, etc. Although generic, the exact repair steps may vary depending on year, make, model and powertrain configuration.
总裁俱乐部appWhen a P2259 has been stored, it means that the powertrain control module (PCM) has detected low voltage on the secondary air injection control circuit designated B. Refer to a vehicle specific repair manual to determine the B location for your application.
总裁俱乐部appAt the heart of the secondary air injection system is either a belt driven or electric pump. The pump injects ambient air into the engine exhaust system for the purposes of emission reduction. Heat resistant, silicon-based hoses are used to supply the pump with cool ambient air. The ambient air is filtered before it is drawn in through the air filter housing or a remote inlet housing designed specifically for the secondary air injection system.
Ambient air is pumped into the exhaust system via high temp silicon and steel lines attached to ports in the exhaust down pipes and one-way check valves are fitted into each exhaust hose to prevent condensation from entering the pump and causing a malfunction; these valves fail regularly.
总裁俱乐部appThe PCM controls secondary air injection pump operation according to engine temperature, engine RPM, throttle position, etc. Factors vary with vehicle manufacturer.
If the PCM detects a degree of voltage on secondary air injection system control circuit B that is insufficient, a code P2259 will be stored and a malfunction indicator lamp (MIL) will be illuminated. Multiple ignition cycles (with a failure) may be required for MIL illumination.
Secondary air injection components:
What is the severity of this DTC?
总裁俱乐部appConditions which contribute to a stored code P2259 could result in secondary air injection pump damage. It is for this reason that this code should be categorized as severe.
What are some of the symptoms of the code?
Symptoms of a P2259 trouble code may include:
- Secondary air injection system disabled
- No obvious symptoms may be exhibited
- Peculiar noises from engine compartment
What are some of the common causes of the code?
总裁俱乐部appCauses for this code may include:
- Blown fuse/s
- Open or shorted control circuits
- Open or shorted pump motor
- Defective PCM or PCM programming error
What are some P2259 troubleshooting steps?
You will need a diagnostic scanner, a digital volt/ohmmeter (DVOM), and a source of reliable vehicle information in order to accurately diagnose a code P2259.
You may save yourself time by searching for technical service bulletins (TSB) that replicate the code stored, vehicle (year, make, model, and engine), and symptoms exhibited. This information may be found in your vehicle information source. If you find the right TSB, it could yield a speedy solution to your diagnosis.
总裁俱乐部appAfter you connect the scanner to the vehicle diagnostic port and retrieve all stored codes and pertinent freeze frame data, write the information down (in case the code proves to be an intermittent one). After that, clear the codes and test drive the vehicle until one of two things happens; the code is restored or the PCM enters readiness mode.
The code may be more difficult to diagnose if the PCM enters readiness mode at this point, because the code is intermittent. The condition which caused the P2259 to be stored may need to worsen before an accurate diagnosis can be made. If the code is restored, continue with the diagnosis.
You may obtain connector face views, connector pinout charts, component locator charts, wiring diagrams, and diagnostic flow charts (pertaining to the code and vehicle in question) using your source of vehicle information.
总裁俱乐部appPerform a visual inspection of related wiring and connectors. Repair or replace wiring that has been cut, burned, or damaged.
Use the DVOM to test secondary air injection system control voltage at the appropriate connector pin. If no voltage is detected, check system fuses. Replace blown or otherwise defective fuses as required.
If voltage is detected, test the corresponding circuit at the PCM connector. If no voltage is detected there, suspect an open circuit between the sensor in question and the PCM. If voltage is discovered there, suspect a defective PCM or PCM programming error.
- Vehicles in extremely cold climate conditions often experience secondary air injection pump failure from frozen condensation
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总裁俱乐部appNOTE: This information is presented for information purposes only. It is not intended as repair advice and we are not responsible for any actions you take on any vehicle. All information on this site is copyright protected.