P0113 Trouble Code: 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 (ambient temp) 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 using the intake air temperature sensor (IAT sensor).

The IAT sensor is a thermistor that varies resistance based on the air intake temperature inside the combustion chamber. A rise in air intake temperature causes a drop in resistance, whereas a cooler ambient temp 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 indicates a problem with the air intake Sensor 1 or IAT sensor 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’ll likely notice: 

• A lit check engine light
• The ECM activates the failsafe mode
• The engine doesn’t start as it usually would
• Engine overheating
• Pre-ignition problems due to lean air-fuel conditions
• Engine misfires
• Poor idling in cold weather 
• Poor fuel economy
• Increased emissions

What’s the failsafe mode?

If your vehicle goes into the failsafe mode (limp mode), your speed will likely be limited to around 40 mph, and your transmission may not shift as usual. 

But don’t panic.
This is the ECM protecting your engine from potentially catastrophic damage. It tunes down your engine so your vehicle can “limp” to a workshop.

Can I Still Drive?

Yes. You can continue to drive with code P0113 for a short period since 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 and reducing your car’s speed.

Ideally, you should try to get the error 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 engine code and cause the check engine light to come on, including: 

• A dirty air filter 
• A damaged intake air temperature sensor (IAT sensor)
• A faulty IAT sensor connector  
• An open circuit in the 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 Powertrain Control Module or Engine Control Module

Diagnosis

If your vehicle supports the OBD-II (On-Board Diagnostics II) system, here’s what a mechanic will do: 

1. Use an OBD II scanner to document the registered fault code. 

2. Check the freeze frame data to analyze the conditions that triggered the error code. 

3. Clear the fault code and test drive your vehicle to see if the check engine light activates and the code returns. 

4. If the code returns, they’ll visually examine the wiring harness between the temp sensor and PCM. They’ll also check the connector to the sensor for an open circuit. 

5. They’ll use an infrared thermometer to check the intake air temperature and coolant temperature when the engine is warm. The intake air temperature should be slightly lower than the coolant temperature.

6. They’ll then remove the sensor from the IAT connector and 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’s no change in the resistance, the IAT needs to be replaced.

7. If none of the above, your mechanic will check for a PCM or ECM malfunction.

Possible Repairs for P0113 & Costs

While the P0113 engine 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 they’ll do: 

• Wiring or connector issues: They’ll replace the faulty wire or connector.

• Temperature sensor (temp sensor) issues: Your mechanic may clean and adjust the temp sensor and ground or replace it if it’s too damaged.

• Air filter issues: They’ll clean or replace a dirty air filter to ensure good air intake.

• MAF sensor or MAF connector issues: Your mechanic will inspect and replace the MAF sensor or MAF connector as necessary.

• PCM issues: They’ll test the PCM and may suggest a replacement.
  

Here are estimated repair costs for some of the fixes, including replacement part and labor charges:

• Air filter replacement: $60 to $80
• Air intake temperature sensor replacement: $85 to $100
• MAF sensor replacement: $235 to $350
• PCM replacement: $1,000 to $1,075

How to Prevent a P0113 Code

Follow these tips to prevent a DTC P0113:

• Regularly clean your air intake temperature sensor. Plus, check for signs of damage, wear, wiring or connector corrosion, and intake system air leaks.

• Perform regular ECM connector checks and software updates to maintain optimum performance.

• Keep up with regular servicing to ensure all components run well.