P0113: High Intake of the Air Temperature Sensor

What is P0113?

P0113 is a generic OBD-II diagnostic trouble code (DTC) defined as “Intake Air Temperature Sensor 1 Circuit High Input.”

The Powertrain Control Module (PCM) or the Engine Control Module (ECM) monitors the air temperature entering your engine to ensure a proper air-fuel mixture. The right air-fuel mix, in turn, provides adequate oxygen to your engine to burn the fuel correctly. Too little air can lead to inadequate combustion, while excess air can eventually damage the engine. 

To prevent this, the PCM monitors the air-fuel mix at all times using the intake air temperature sensor (IAT sensor).

The IAT sensor is a thermistor that varies resistance based on the air temperature inside the combustion chamber. A rise in air intake temperature causes a drop in its thermistor’s resistance, whereas cooler temperature results in higher resistance in the temperature sensor. 

Your vehicle’s PCM sends 5 volts of reference voltage to the IAT sensor. 

If the PCM receives a signal voltage higher than 5 volts from the air temperature sensor, it means there’s a problem with air intake Sensor 1 or its circuit. 

As a result, the PCM logs the P0113 code, and the check engine light illuminates.

Common symptoms

If your vehicle’s ECM or PCM has registered the P0113 code, you’re likely to witness these symptoms: 

• An illuminated check engine light (or malfunction indicator lamp) 
• The Engine Control Module activates the failsafe mode
• The engine doesn’t start as it usually would
• The air or fuel mixture is too lean or rich
• You experience pre-ignition problems due to lean air-fuel conditions
• Poor idling in cold weather 
• Poor fuel economy
• Increased emissions

What’s the failsafe mode?

If your vehicle goes into the failsafe mode (also called “limp mode”), your speed will likely be limited to 40 mph or so, and your transmission may not shift as usual. But don’t panic. This is the PCM/ECM protecting your engine from potentially catastrophic damage. It tunes down your engine so you can literally “limp” your vehicle to a workshop.

Can I still drive?

Yes. You can continue to drive with code P0113 for a short period as it doesn’t signify any car trouble that needs immediate attention. 

However, your car’s ECM may switch to a failsafe mode, disabling certain features of your vehicle and reducing your car’s speed. 

Ideally, you should try to get the code diagnosed and resolved quickly, as driving with DTC P0113 for extended periods can lead to internal engine damage. It could also damage the catalytic converter, which is a pretty expensive repair.

P0113 causes

Several reasons could trigger the P0113 code and cause the check engine light to come on. Some of these common causes include: 

• A dirty air filter 
• A damaged intake air temperature sensor (IAT sensor)
• A faulty IAT sensor connector  
• An open IAT ground circuit or signal circuit
• A shorted IAT signal circuit 
• The IAT sensor wiring harness is routed too close to a high voltage wiring (like a spark plug wire or alternator)
• A faulty mass air flow sensor (MAF sensor)
• A faulty PCM or ECM

Diagnosis

DTC P0113 is a generic OBD-II (or OBD2) trouble code — meaning it applies to any vehicle that supports the On-Board Diagnostics II system. 

If your vehicle supports the OBD-II system, here’s how a mechanic will diagnose the P0113 code: 

• They’ll use an OBD II scanner to document the registered code. 
• They’ll check the freeze frame data to analyze the conditions that triggered the code. 
• They’ll then clear the fault code and test drive your vehicle to see if the check engine light turns on and the code returns. 
• If the code returns, they’ll first visually examine the wiring harness between the temperature sensor and the PCM. They’ll also check the connector to the sensor and look for any open circuit. 
• Next, they’ll use an infrared thermometer to check the intake air temperature and coolant temperature when the engine is warm. When working correctly, the intake air temperature should be slightly lower than the coolant temperature.
• They’ll then remove the sensor from the IAT connector and use a multimeter to test the resistance of the air temperature sensor. They’ll apply heat to the IAT sensor tip to check if the resistance decreases. If there is no change in the resistance reading, the IAT is faulty and should be replaced.
• However, if no faults are found in the above steps, your mechanic will inspect the PCM or ECM for any malfunction.

Possible repairs for P0113 & Costs

While the P0113 code is a generic powertrain code, the specific repair steps can vary depending on your vehicle’s make and model. That said, there are certain standard fixes that your mechanic can resort to for resolving the code. 

After identifying the root cause, here’s what your mechanic may do: 

• Wiring or connector issues: If the problem is with the wiring and the connector for the IAT sensor or if there’s any short circuit, your mechanic will replace the faulty wire or connector. 
• Temperature sensor issues: If they detect any fault in the temperature sensor, your mechanic may clean and adjust the sensor and its ground, or replace the sensor if it’s too damaged. 
• Air filter issues: If the cause of the trouble code is a dirty or damaged air filter, your mechanic will clean or replace the filter to ensure good air intake. 
• MAF sensor issues: Sometimes, the mass air flow sensor and MAF connector may be at fault too. In that case, your mechanic will inspect the MAF sensor and its connector and replace them as necessary. 
• PCM issues: If nothing else resolves the code, your mechanic will test the PCM and may suggest a replacement. 

Here are estimated repair costs for some of the fixes:

• Air intake temperature sensor replacement: $87 to $96
• Air filter replacement: $40 to $85
• MAF sensor replacement: $80 to $380
• PCM replacement: $800 to $1,500

Note: The above estimates include the cost of the relevant parts and labor charges.