P0127 Code: Intake Air Temperature Too High

Trouble codes are a set of numbers and letters that indicate the nature and location of a potential issue within your vehicle. When these codes are stored, the vehicle’s computer illuminates the check engine light to alert you that an error is present.

The P0127 code is a trouble code indicating a possible problem with the intake air temperature sensor or its circuit. What does this code mean and what signs should you look out for? Find out with this brief guide.

What Does the P0127 Code Mean?

Diagnostic trouble code (DTC) P0127 stands for “Intake Air Temperature Too High.” This code indicates higher than expected air temperature based on the sensor input, which can be skewed due to a bad thermistor or a partially shorted circuit.

Most vehicles don’t have code P0127 in their list. Nissan is one of the vehicles that list this code. On a Nissan, the intake air temperature sensor is built into the mass air flow sensor, and the temperature sensing unit uses a thermistor which is sensitive to the change in temperature. Electrical resistance of the thermistor decreases in response to the temperature rise.

Most vehicles don’t have code P0127 in their list. Nissan is one of the vehicles that list this code.

– Richard McCuistian, ASE Certified Master Automobile Technician

Since the intake air temperature sensor’s input is crucial to the PCM’s calculation of fuel delivery strategy, this code must be addressed immediately.

If you’re planning to troubleshoot P0127 yourself, read our discussion about what an IAT sensor is and how it can cause OBD codes to get logged.

Note: The definition of code P0127 may be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.

What Are the Possible Causes of the P0127 Code?

Trouble codes can only indicate the nature and location of a potential issue, not the exact root cause. This is why many trouble codes have multiple possible triggers. Like many diagnostic trouble codes, the P0127 code has a number of possible causes, some of which are listed below:

• Intake air temperature sensor failure
• Wiring issues such as open or shorted intake air temperature sensor wiring and/or connectors
• Faulty mass air flow (MAF) sensor (sometimes the IAT is integrated into the MAF)
• Defective intake air inlet pipe
• PCM failure

What Are the Common Symptoms of the P0127 Code?

When the vehicle’s computer system detects a potential issue, it stores the information as a diagnostic trouble code and sends a signal to illuminate the check engine light. In many cases, it may be the only sign of an existing error. For other trouble codes such as the P0127, other symptoms may also be present. Listed below are some of the indicators of a P0127 code:

• Malfunction indicator lamp (MIL) or check engine light on
• Poor fuel efficiency
• Decreased engine performance
• Other drivability codes may also be stored

How to Diagnose the P0127 Code

Proper diagnosis of a diagnostic trouble code requires accuracy and precision. Trouble codes have multiple possible causes, so it may take some effort and time to narrow down the root cause of the issue. In addition, misdiagnosis is also a possibility, which can cost you even more in future repairs.

In order to get an accurate diagnosis, you will need reliable sources of repair information. The best resources you can use are vehicle-specific repair manuals and databases, which contain accurate troubleshooting instructions as well as helpful diagrams and illustrations.

Technical service bulletins (TSBs), which can often be found through a repair database, may also help you get more information about a trouble code. TSBs are especially helpful if your vehicle’s manufacturer released one that’s applicable to the model you own. Other resources you can use and access online include how-to videos, blogs, and digital magazines.

How to Fix the P0127 Code

Fixing trouble codes is difficult enough because you have to accurately diagnose the problem first. That in itself is challenging already because a trouble code can have multiple possible causes.

Another factor that may complicate your troubleshooting process is the fact that vehicles aren’t built the same. Different manufacturers will have different terminologies, components, and repair instructions for their vehicles. For example, the setting conditions for a P0127 on a Volvo vehicle are different from those of a P0127 on a Nissan vehicle.

Because vehicles are manufactured differently, you definitely need a reliable and vehicle-specific repair manual to help you address the issue at hand. However, doing trouble code repairs on your vehicle without the right technical know-how may be dangerous and potentially damaging to your vehicle. That’s why if in doubt, have a certified professional do the repairs for you.

Find the Right Air Temperature Sensor

A problem with the air temperature sensor can prompt the PCM to set diagnostic trouble codes like the P0127 code. Replace the faulty sensor to avoid creating more issues. Take advantage of hassle-free searching at CarParts.com and find a replacement air temperature sensor that fits your vehicle.

CarParts.com understands the importance of getting the right air temperature sensor for your car or truck. We offer an extensive array of air temperature sensors for various vehicle makes and models. Find a compatible replacement part by entering the details of your car or truck in our easy-to-use vehicle selector. Got questions about the fitment, price tag, and other features of the air temperature sensor? Our knowledgeable customer service team is available 24/7 to assist you. Once you complete your order, you can expect to receive your new air temperature in as fast as two days if you live in the continental US and complete the ordering process before noon PT.

Enjoy big savings on your new air temperature sensor at CarParts.com. Check out our air temperature sensors today!

Products Mentioned in this Guide

Air Temperature Sensor Mass Air Flow Sensor Engine Control Module