P1613 – Secondary air injection (AIR) – malfunction (Toyota)

By Reinier (Contact Me)
Last Updated 2023-06-26
Automobile Repair Shop Owner

Manufacturer Specific Definitions for P1613

Table of Contents

1. What Does Code P1613 Mean?
2. Where is the P1613 sensor located?
3. What are the common causes of code P1613?
4. What are the symptoms of code P1613?
5. Get Help with P1613

What Does Code P1613 Mean?

OBD II fault code P1613 is a manufacturer-specific trouble code that is defined by carmaker Toyota as, P1613 – “Secondary air injection (AIR) – malfunction”, and is set when the PCM (Powertrain Control Module) detects a malfunction anywhere in the secondary air injection system.

The purpose of secondary air injection systems is to force ambient air into the exhaust system to aid in bringing catalytic converters into closed-loop operation sooner, especially in cold climates to reduce harmful exhaust emissions.

Although modern catalytic converters reach their optimal operating temperatures relatively quickly, there remains a short time after starting a cold engine during which a catalytic converter is inactive. So, while some car manufacturers have begun installing electric heating elements into catalytic converters to reduce this inactive period, other manufacturers such as Toyota, have chosen to retain secondary air injection systems to reduce converter warm-up times.

In terms of operating principles, the secondary air injection system consists of an air pump, a vacuum-controlled switching valve, a combination valve, and a control relay that is energized by the PCM to activate the system. In practice, the PCM monitors the engine temperature at startup and activated the secondary air injection system when the engine’s temperature falls below a minimum threshold.

When the system is activated, the air pump forces ambient air into the exhaust system after (or behind) the exhaust valves, and since ambient air contains a high concentration of oxygen, the additional oxygen assists in a) raising the temperature of the exhaust gas, and b) assists in initiating the process that converts harmful exhaust emissions into innocuous substances like water vapor and carbon dioxide.

In most cases, the additional oxygen will bring the catalytic converter into closed-loop operation in about 100 seconds. However, to make sure that the converter is indeed active, the PCM will check and compare the output signals of the upstream and downstream oxygen sensors or air/fuel ratio sensors to confirm that the converter is active before deactivating the secondary air injection system.

It is perhaps worth mentioning at this point that modern secondary air injection systems are arguably far more complicated than they need to be, and since code P1613 refers to undefined faults, defects, and failures, it can be extremely challenging even for professional mechanics to diagnose and repair these systems.

Nonetheless, if the PCM detects a fault, failure, or malfunction anywhere in the secondary air injection system that it cannot categorize or classify, it will recognize that it cannot control the secondary air injection system effectively, and by extension, the engines’ overall emissions, and it will set code P1613 as a result. It is worth noting that since this code has the potential to affect the vehicles’ exhaust emission levels, the PCM will also illuminate a warning light immediately when it detects a failure or malfunction in this system.

Where is the P1613 sensor located?

This image shows the location of the secondary air pump on a 5th-generation Toyota 4Runner, but note the small red air filter to the right of the pump. While this, or similar filters are a common feature on late-model vehicles, older vehicles are usually not equipped with dedicated filters for the air pump, which is a leading cause of air pump failures on older Toyota models.

Note, though, that secondary air injection pumps on Toyota models come in a variety of shapes, designs, and capacities, which means that these pumps are not interchangeable, even if any given pump appears to fit multiple models. Note, in addition, that the locations of secondary air injection pumps vary between different Toyota models, so we strongly recommend that you research the exact location of the air pump on an affected vehicle before attempting a diagnostic or repair procedure that involves the secondary air injection system.

What are the common causes of code P1613?

NOTE: The enabling conditions that must be met before code P1613 are not only many, varied, and complicated, but they are also difficult to determine without the assistance of both OEM service information and OEM-level diagnostic equipment. Therefore, we strongly recommend that non-professional mechanics seek professional assistance with diagnosing and repairing the secondary air injection system on any Toyota application. Note that failure to do so could result in misdiagnoses, and even irreparable damage to control modules, including but not limited to the PCM, and the vehicle’s larger electrical system.

Nonetheless, some common causes of code P1613 could include one or more of the following-

• Damaged, burnt, shorted, disconnected, or corroded wiring and/or electrical connectors anywhere in the secondary air injection system
• Damaged, or defective air injection pump (Common)
• Damaged or dislodged switching valve vacuum lines
• Damaged or defective switching valve
• Blown fuses and/or fusible links
• Defective or malfunctioning engine coolant temperature sensor(s)
• Damaged or corrupted air injection driver circuits in the PCM

WARNING: Testing any of the above conditions can only be performed with OEM-level diagnostic equipment, and then only strictly by following OEM-specified test procedures. Therefore, any attempt to perform testing on this system outside of OEM-specified procedures and methods will almost certainly result in severe and possibly fatal damage not only to the secondary air injection system but also to other components that may include control modules.

What are the symptoms of code P1613?

Common symptoms of code P1613 could include the following but note that this code does not usually produce noticeable or significant drivability issues-

• Stored trouble code and an illuminated warning light that may flash, depending on the nature of the problem
• In some cases, additional trouble codes may be present along with P1613, with code P1614 – “Secondary Air Injection System Driver” being relatively common
• Some readiness monitors may not initiate or run to completion
• The vehicle will not pass a mandatory emissions test

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