P2259 Low rate of secondary air injection control circuit B

P2259 Low rate of secondary air injection control circuit B

OBD-II DTC Datasheet

Low signal level in the secondary air injection system control circuit B

What does P2259 mean?

This Diagnostic Trouble Code (DTC) is a generic transmission code and applies to many OBD-II vehicles (1996 and newer). This may include but is not limited to Mazda, BMW, Ford, Dodge, Saab, Range Rover, Jaguar, etc. Despite the general nature, the exact repair steps may vary depending on the model year, make, model and configuration. transmissions.

Retention of P2259 means that the powertrain control module (PCM) has detected a low voltage in the secondary air injection control circuit indicated by B. Refer to the vehicle-specific repair manual to determine the B location for your application.

The secondary air injection system is based on a belt driven or electric pump. The pump pumps ambient air into the engine's exhaust system to reduce emissions. Silicone-based heat-resistant hoses are used to supply the pump with cold ambient air. Ambient air is filtered before being sucked in through an air filter housing or remote inlet housing designed specifically for secondary air injection systems.

Ambient air is pumped into the exhaust system through high-temperature silicon and steel piping attached to ports in the exhaust pipes, and one-way check valves are built into each exhaust hose to prevent condensation from entering the pump and causing it to malfunction; these valves fail regularly.

The PCM controls the operation of the secondary air injection pump based on engine temperature, engine speed, throttle position, etc. Factors vary depending on the vehicle manufacturer.

If the PCM detects an undervoltage in the secondary air injection system B control circuit, P2259 will store and a malfunction indicator lamp (MIL) will illuminate. MIL may require multiple ignition cycles (with failure) to illuminate.

Secondary air supply components:

What is the severity of this DTC?

Conditions that contribute to the persistence of P2259 could damage the secondary air injection pump. It is for this reason that this code should be categorized as serious.

What are some of the symptoms of the code?

Symptoms of a P2259 trouble code may include:

• Secondary air injection system disabled
• There can be no obvious symptoms.
• Peculiar noises from the engine compartment

What are some of the common causes for the code?

Reasons for this code may include:

• Fuse blown / s
• Open or short circuit in control circuits
• Open or short circuit of the pump motor
• Faulty PCM or PCM programming error

What are some steps to troubleshoot the P2259?

You will need a diagnostic scanner, digital volt / ohmmeter (DVOM), and reliable vehicle information source to accurately diagnose the P2259 code.

You can save time by searching for Technical Service Bulletins (TSBs) that reproduce the stored code, vehicle (year, make, model, and engine) and symptoms found. This information can be found in your vehicle information source. If you find the right TSB, it can quickly fix your problem.

After you connect the scanner to the vehicle diagnostic port and get all stored codes and associated freeze frame data, write down the information (in case the code turns out to be intermittent). After that, clear the codes and test drive the car until one of two things happens; the code is restored or the PCM enters ready mode.

The code may be more difficult to diagnose if the PCM enters ready mode at this point because the code is intermittent. The condition that led to the persistence of P2259 may need to worsen before an accurate diagnosis can be made. If the code is restored, continue diagnostics.

You can get connector views, connector pinouts, component locations, wiring diagrams, and diagnostic block diagrams (related to the code and the vehicle in question) using your vehicle information source.

Visually inspect the associated wiring and connectors. Repair or replace cut, burnt, or damaged wiring.

Use the DVOM to test the secondary air injection control voltage at the appropriate pin on the connector. If no voltage is found, check the system fuses. Replace blown or defective fuses if necessary.

If voltage is detected, check the appropriate circuit at the PCM connector. If no voltage is detected, suspect an open circuit between the sensor in question and the PCM. If voltage is found there, suspect a faulty PCM or a PCM programming error.

• In vehicles operating in extremely cold climates, the secondary air injection pump often fails due to frozen condensate.

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