# P0113: Intake Air Temperature Sensor 1 Circuit High (Bank 1) **Verdict:** Safe to drive Air intake - Generic OBD-II code, applies to all gasoline cars and light trucks sold in the US since 1996. - **Typical cost:** $20-$400 - **Urgency:** Keep driving - **Most likely:** Unplugged connector or failed IAT sensor - **DIY?:** Yes, steps 1-3 ## Quick answer P0113 means the signal from the intake air temperature (IAT) sensor is reading too high on voltage, which the computer sees as extremely cold air. That almost always means an open circuit such as an unplugged connector, a broken wire or a failed sensor. ## What does P0113 mean? The intake air temperature (IAT) sensor measures the temperature of air entering the engine. It is a thermistor, a resistor whose value drops as it warms. The engine computer feeds it a reference voltage, usually 5 volts, and reads the voltage left on the signal wire. Cold air means high resistance and high voltage; warm air means low resistance and low voltage. The computer uses the reading to fine-tune fuel and spark. P0113 sets when the signal voltage stays near the top of its range, which the computer reads as impossibly cold air, often around -40 degrees on a scan tool. That nearly always points to an open circuit: an unplugged connector, a broken wire or a failed sensor. Many makers set it after a few seconds of the fault on one or two trips. "Sensor 1" is the main IAT sensor, which on many cars is built into the MAF sensor. ## What are the symptoms of P0113? - Check engine light on - Car usually runs normally - Possible hard starting or rough running when warm - Slightly worse fuel economy ## What causes P0113? Ranked from most to least likely. Check them in this order: the cheap, common causes first. 1. **Unplugged or loose IAT sensor connector** (most common). The IAT sensor is often in the air box, the intake tube or built into the MAF sensor, so it gets unplugged during air filter changes and other engine work. A plug left loose, or one with a broken lock tab, opens the circuit. Check the connection first, since it is the cheapest and most frequent fix. 2. **Failed IAT sensor** (common). The thermistor inside the sensor can crack or open with age and heat cycling. An open sensor reads as extremely cold, often around -40 degrees on a scan tool, no matter the weather. Measuring its resistance with a multimeter, and watching it change as you warm the tip, confirms whether the sensor itself is at fault. 3. **Broken or corroded signal or ground wire** (less common). A break in either the signal wire or the ground wire makes the voltage go high, which the computer reads as very cold air. Look for corrosion in the connector, pins that have backed out, and damage along the harness where it bends near the air box or rubs on brackets. Rodent damage is another possibility. 4. **Failed MAF sensor (where the IAT is built in)** (less common). On many cars the IAT is built into the MAF sensor and shares its connector, so an internal fault in the IAT element sets P0113 while airflow readings stay normal. The IAT part usually cannot be replaced on its own in these designs, so the whole MAF assembly is replaced, which costs more than a separate sensor. ## How do you diagnose P0113? 1. Read live data with the engine cold; IAT should match outside air temperature within a few degrees. 2. A reading of about -40 degrees means an open circuit; check the connector first. 3. Unplug the sensor and measure its resistance; it should change as you warm it with your hand or a hair dryer. 4. With the sensor unplugged, jumper the two harness pins; the scan tool should jump to a very high temperature if the wiring is good. 5. Replace the sensor if wiring tests good and the sensor resistance is out of range. ## How do you fix P0113, and what does it cost? | Fix | Typical cost | What it involves | | --- | --- | --- | | Reconnect or repair the IAT connector or wiring | $20-$200 | Often just reseating or cleaning the plug. | | Replace the IAT sensor | $50-$200 | Stand-alone sensors are inexpensive and usually plug and twist in. | | Replace the MAF sensor with built-in IAT | $150-$400 | Needed when the IAT is integrated into the MAF. | Full price breakdowns: [mass air flow sensor replacement cost](/cost/mass-air-flow-sensor-replacement). ## Is it safe to drive with P0113? > **Safe to drive.** Yes, it is usually safe to drive. The computer substitutes a default air temperature, so most cars run close to normal, but have it fixed to keep the engine running at its best. ## Will P0113 fail an emissions test? P0113 turns on the check engine light, so the car fails an OBD-II emissions test in most states even though it may drive normally. With a default air temperature, fuel control is a little less precise. After the repair, clearing the code resets the readiness monitors, so drive for several days before testing and confirm the monitors are ready. ## After the repair: clearing P0113 Clear the code after reconnecting or replacing the sensor, then check live data on a cold engine: IAT should read close to outside air temperature, within a few degrees. Once you drive, it rises a little with under-hood heat. Because this is a circuit check, a good repair usually shows at once. Recheck for pending codes after several trips. ## How to prevent P0113 - After air filter changes, make sure the IAT or MAF plug clicks fully into place. - Route the IAT harness away from sharp edges and hot parts when refitting the air box. - Keep the air box sealed so water and dirt cannot reach the sensor connector. - Press the lock tab and pull the plug body, never the wires, when unplugging sensors. - Check the air box for rodent nests if the car sits unused for long periods. ## Codes often seen with P0113 - [P0101](/codes/p0101): Mass or Volume Air Flow "A" Circuit Range/Performance - [P0102](/codes/p0102): Mass or Volume Air Flow "A" Circuit Low - [P0128](/codes/p0128): Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature) ## Frequently asked questions ### Where is the intake air temperature sensor? It is usually in the air intake tube, the air filter box, or built into the mass air flow sensor. Some engines also have a second sensor after the turbocharger or in the intake manifold. Your repair manual or a parts catalog for your car shows the exact location and which one is sensor 1. ### Why does my scan tool show -40 degrees intake air temperature? A reading of -40 degrees means the computer sees an open circuit, because that is the lowest value it can display. The sensor is unplugged, a wire is broken or the sensor has failed, which is exactly what sets P0113. Testing with the sensor unplugged and the harness pins jumpered tells you which. ### Is P0113 serious? No, P0113 is one of the less serious codes. The car usually runs fine on a default air temperature value. Fix it soon so you pass emissions and so the check engine light can warn you of anything new, because a light that is already on hides future problems. ### Can I drive with P0113? Yes, it is usually safe to drive with P0113. The computer uses a default air temperature, so most cars run close to normal, though some may start harder or run slightly rough when hot. Plan to fix it within a few weeks, and sooner if an emissions test is coming up. ### How much does it cost to fix P0113? Most P0113 repairs cost $20-$400 at an independent shop. Reseating or cleaning the connector costs little beyond diagnosis, a stand-alone IAT sensor installed is about $50-$200, and a MAF sensor with a built-in IAT runs $150-$400. Wiring repair falls in between, depending on where the damage is. ### Can I fix P0113 myself? Yes, P0113 is a good DIY code. Check the plug, then test the sensor with a multimeter by measuring resistance cold and again after warming it with your hand or a hair dryer; it should drop as it warms. Stand-alone sensors usually twist or clip in with no special tools. ### How do I test the IAT sensor wiring? Unplug the sensor and, with the key on, briefly connect the two harness pins with a fused jumper wire. If the scan tool reading jumps to a very high temperature, the wiring and computer are good and the sensor is at fault. If it stays at -40 degrees, look for a broken wire. ### What is the difference between P0113 and P0112? P0113 means the IAT signal voltage is too high, which reads as very cold and usually points to an open circuit. P0112 means the voltage is too low, which reads as very hot and usually points to a short to ground or a failed sensor. The sensor and wiring checks are similar. ### Can P0113 cause poor gas mileage? Slightly, in some cars. The computer uses air temperature to fine-tune fuel and spark timing, and a default value is less accurate than a real reading. Most drivers notice little change, but the check engine light staying on is the bigger concern because it can mask other faults. ### Can cold weather set P0113? No, a cold day will not set it on a healthy system, because real outside temperatures stay well above the -40 degrees an open circuit reads. If P0113 shows up only in wet or cold weather, suspect moisture in the connector or a cracked wire that loses contact as it contracts in the cold. ## Sources - [SAE J2012: Diagnostic Trouble Code Definitions](https://www.sae.org/standards/content/j2012_201812/) ## Other air intake codes - [P0102 Mass or Volume Air Flow "A" Circuit Low](https://diagxcar.com/codes/p0102) - [P0106 Manifold Absolute Pressure/Barometric Pressure Circuit Range/Performance](https://diagxcar.com/codes/p0106) - [P0107 Manifold Absolute Pressure/Barometric Pressure Circuit Low](https://diagxcar.com/codes/p0107) - [P0108 Manifold Absolute Pressure/Barometric Pressure Circuit High](https://diagxcar.com/codes/p0108) - [P0112 Intake Air Temperature Sensor 1 Circuit Low (Bank 1)](https://diagxcar.com/codes/p0112) - [P0117 Engine Coolant Temperature Sensor 1 Circuit Low](https://diagxcar.com/codes/p0117) - [P0118 Engine Coolant Temperature Sensor 1 Circuit High](https://diagxcar.com/codes/p0118) - [P0121 Throttle/Pedal Position Sensor/Switch "A" Circuit Range/Performance](https://diagxcar.com/codes/p0121) - [P0122 Throttle/Pedal Position Sensor/Switch "A" Circuit Low](https://diagxcar.com/codes/p0122) - [P0123 Throttle/Pedal Position Sensor/Switch "A" Circuit High](https://diagxcar.com/codes/p0123) - [P0101 Mass or Volume Air Flow "A" Circuit Range/Performance](https://diagxcar.com/codes/p0101) - [P0128 Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)](https://diagxcar.com/codes/p0128) ## Repair costs - [Mass air flow sensor replacement cost](https://diagxcar.com/cost/mass-air-flow-sensor-replacement): $150-$450 --- Source page: https://diagxcar.com/codes/p0113 Updated: 2026-11-03 General information, not a substitute for a qualified mechanic.