P0113
Intake Air Temperature Sensor 1 Circuit High Input
Published · Reviewed and updated
In plain English: The engine computer saw intake-air-temperature sensor 1 voltage too high, which usually appears as impossibly cold air on scan data; high input does not mean the incoming air is too hot.
A short, gentle trip is usually possible if the engine starts and runs normally, but fuel mixture, ignition timing, boost and emissions controls may use substitute values. Stop and arrange service if the engine stalls, runs severely rich, produces heavy smoke, loses substantial power or sets another warning that changes the safety picture.
A diagnostic starting point: Loose connector, pushed-out pin or spread terminal. Start by asking: After a proper cold soak, is IAT 1 implausibly colder than ambient and coolant? Illustrative parts budgets span $0–$1600 USD, with diagnosis, labor and taxes extra.
Quick answers about P0113
- What does P0113 mean?
- The engine computer saw intake-air-temperature sensor 1 voltage too high, which usually appears as impossibly cold air on scan data; high input does not mean the incoming air is too hot.
- What should I check first for P0113?
- One starting point is Loose connector, pushed-out pin or spread terminal. A terminal that looks connected can lose the signal or sensor-return contact when vibration or wire strain moves it. The code alone does not identify a failed part; follow the procedure for your vehicle.
- Can I drive with P0113?
- A short, gentle trip is usually possible if the engine starts and runs normally, but fuel mixture, ignition timing, boost and emissions controls may use substitute values. Stop and arrange service if the engine stalls, runs severely rich, produces heavy smoke, loses substantial power or sets another warning that changes the safety picture.
- How much does it cost to fix P0113?
- Illustrative parts budgets in this guide span $0–$1600 USD. Diagnosis, labor and taxes are extra. Test the connector and circuit response before replacing an integrated sensor.
- How do I diagnose P0113?
- Start with: After a proper cold soak, is IAT 1 implausibly colder than ambient and coolant? Save every code and freeze frame before clearing anything. Compare all temperatures key-on engine-off and confirm the scan tool is showing the correct IAT parameter; an ordinary reading now points toward an intermittent fault or enabling condition.
Watch the P0113 videos
Full walkthrough — 9:34. Watch on YouTube
What P0113 actually means
Most intake-air-temperature sensors are negative-temperature-coefficient thermistors. The engine computer supplies a pull-up voltage and watches the signal through the sensor to its return circuit. Cold air raises thermistor resistance and signal voltage; warm air lowers resistance and voltage. The computer converts that voltage into a temperature used for fueling, timing, boost and emissions calculations.
P0113 sets when the IAT 1 signal remains above the calibrated electrical limit, or the calculated temperature remains below the allowed minimum, for the required time. Manufacturer examples include more than 4.47 volts or a calculated temperature below roughly minus 45 degrees Celsius, but those are examples rather than universal specifications. An unplugged sensor, open signal or open return can all pull the reading high.
Symptoms
- Check-engine light with an implausibly cold IAT readingThe scan value may be near the tool's lower limit even when the engine bay and outside air are warm.
- Hard starting, rough cold operation or hesitationA false cold value can alter commanded fuel, spark and airflow strategies.
- Reduced fuel economy or a fuel smellSome gasoline calibrations enrich the mixture when the computer believes the intake air is extremely cold.
- Reduced power or changed boost and emissions behaviorTurbocharged and diesel applications may substitute values or limit a temperature-dependent control.
- Sometimes no symptom beyond the warning lightA plausible substitute value can hide the failed input during ordinary driving.
Possible causes and what to check
This is a practical diagnostic order, not measured failure rates. Follow the tests and priorities specified for your vehicle; a code alone does not identify a failed part.
The fast clue: IAT compared with ambient after a cold soak
Illustrative graph, not a recording from your vehicle or a universal service limit. Confirm the test conditions, units and acceptance criteria in the applicable service procedure.
After the vehicle has sat long enough to equalize, turn the key on before starting and compare intake-air temperature with ambient air and engine coolant temperature. This graph is illustrative; use the vehicle's specified soak time and allowable difference.
A known-good IAT begins near the other cold-soaked temperature readings, then rises gradually from engine-bay heat and airflow after startup. The values do not need to be identical, but they should make physical sense.
The P0113 trace stays near an extreme cold default while ambient and coolant are ordinary. An intermittent open can jump instantly between a believable value and the cold limit when the connector or harness moves.
If scan data is implausibly cold, inspect the connector before unplugging it, then use the factory-approved resistor, simulator or back-probe test. If the displayed temperature responds, the sensor or its connection is suspect; if it does not, trace the signal and return to the computer.
How to diagnose it, in order
-
After a proper cold soak, is IAT 1 implausibly colder than ambient and coolant?Save every code and freeze frame before clearing anything. Compare all temperatures key-on engine-off and confirm the scan tool is showing the correct IAT parameter; an ordinary reading now points toward an intermittent fault or enabling condition.Yes → go to step 2No → Use freeze-frame data and monitor the circuit for an intermittent open
-
Is the correct sensor fully connected with clean, tight and seated terminals?Inspect before disconnecting so a pushed-out pin is not accidentally reseated. Check connector locks, wire strain, corrosion and harness routing, especially when IAT is integrated into another airflow or pressure sensor.Yes → go to step 3No → Repair the terminal, connector, strain or corrosion problem
-
Does scan temperature respond correctly to the approved resistor or simulator test?Use only the factory test value and pinout. Never short a five-volt reference directly to ground. If the displayed temperature moves to the specified value, the computer and most of the harness can see a valid resistance.Yes → Verify mounting and replace the proven open IAT element or integrated sensorNo → go to step 4
-
Do signal, return, continuity and short-to-voltage tests meet specification?Test both conductors end to end and under light harness movement, then load-test the return where the procedure requires it. Check shared references before condemning an integrated MAF, MAP or pressure sensor.Yes → go to step 5No → Repair the open, high resistance, powered short or shared circuit
-
Does the correct signal voltage and temperature relationship reach the PCM pins?Prove the signal at the controller under the same condition. If it is correct there but scan data remains wrong, verify connector fit, grounds and software before considering the rare PCM input fault.Yes → Verify calibration and PCM input as the final branchNo → Repair the remaining signal or return path to the PCM
Start with the impossible temperature, preserve the connector evidence, and prove where the pull-up circuit opens before replacing an integrated sensor.
What you need to do this yourself
- A scan tool that reads live data — Choose vehicle-compatible access to the live data, freeze frame and monitor results required by the diagnostic procedure. Some checks also need bidirectional control.
- Digital multimeter — Use the specified meter and test method for electrical checks. Follow circuit diagrams and avoid applying an unsuitable test load to a computer driver.
- Vehicle-specific service information — Confirm the procedure, safety precautions, tools and acceptance limits for the exact year, model and engine.
Some links may be affiliate links. They cost you nothing extra and do not change which tools are recommended — the diagnostic order on this site is the same either way.
Illustrative repair budgets
These are rough US planning examples, not quotes or measured repair averages. Parts and labor are separate; diagnosis, taxes, difficult access and additional repairs can increase the total.
| Repair | Parts (USD) | Labor time |
|---|---|---|
| Connector terminal or pigtail repair A pushed-out or spread terminal may need a correct terminal repair rather than a complete sensor. |
$10–$180 | 1.0 h |
| Accessible signal or return wiring repair Cost rises when the open is inside a wrapped engine harness or shared splice. |
$10–$400 | 1.5 h |
| Standalone intake-air-temperature sensor Confirm the connector and response test first because many standalone sensors are easy to replace and easy to misdiagnose. |
$15–$140 | 0.5 h |
| Integrated MAF, MAP or charge-pressure sensor Replace the combined assembly only after proving its IAT element failed while its wiring remained intact. |
$60–$550 | 1.0 h |
| PCM connector, software or module repair The rare final branch after the correct resistance and voltage relationship is proven at the controller. |
$0–$1600 | 2.0 h |
Test the connector and circuit response before replacing an integrated sensor.
P0113 video summary · 1:14
A brief introduction to the code and a diagnostic starting point. Use the full guide and vehicle-specific service information for the complete procedure.
Written diagnostic walkthrough
Current written guidance organized by topic. This text may include corrections made after a video was published and is not a verbatim transcript of the archived video.
Meaning and driving guidance
Code P0113. Intake Air Temperature Sensor 1 Circuit High Input.
In plain English: the engine computer saw intake-air-temperature sensor 1 voltage too high, which usually appears as impossibly cold air on scan data; high input does not mean the incoming air is too hot.
A short, gentle trip is usually possible if the engine starts and runs normally, but fuel mixture, ignition timing, boost and emissions controls may use substitute values. Stop and arrange service if the engine stalls, runs severely rich, produces heavy smoke, loses substantial power or sets another warning that changes the safety picture.
How it is measured
Here's what your engine computer is actually measuring.
Most intake-air-temperature sensors are negative-temperature-coefficient thermistors. The engine computer supplies a pull-up voltage and watches the signal through the sensor to its return circuit. Cold air raises thermistor resistance and signal voltage; warm air lowers resistance and voltage. The computer converts that voltage into a temperature used for fueling, timing, boost and emissions calculations.
P0113 sets when the IAT 1 signal remains above the calibrated electrical limit, or the calculated temperature remains below the allowed minimum, for the required time. Manufacturer examples include more than 4.47 volts or a calculated temperature below roughly minus 45 degrees Celsius, but those are examples rather than universal specifications. An unplugged sensor, open signal or open return can all pull the reading high.
So the code is not a part failure report. It's a performance measurement that came back under spec.
Symptoms
What you'll usually notice, beyond the light itself.
Check-engine light with an implausibly cold IAT reading. The scan value may be near the tool's lower limit even when the engine bay and outside air are warm.
Hard starting, rough cold operation or hesitation. A false cold value can alter commanded fuel, spark and airflow strategies.
Reduced fuel economy or a fuel smell. Some gasoline calibrations enrich the mixture when the computer believes the intake air is extremely cold.
Reduced power or changed boost and emissions behavior. Turbocharged and diesel applications may substitute values or limit a temperature-dependent control.
Sometimes no symptom beyond the warning light. A plausible substitute value can hide the failed input during ordinary driving.
Possible causes
Here is a practical order for checking the possible causes. These are diagnostic priorities, not measured failure rates.
Check 1: Loose connector, pushed-out pin or spread terminal. A terminal that looks connected can lose the signal or sensor-return contact when vibration or wire strain moves it.
Check 2: Open or broken wire in the IAT signal or return circuit. Harness rub-through, a broken conductor or a poor splice can leave the pull-up voltage near its maximum.
Check 3: Internally open IAT thermistor or integrated sensor. The temperature element may fail by itself even when it shares a housing with the MAF, MAP or pressure sensor.
Check 4: Corrosion, moisture or high resistance at a connector or ground. Resistance added to the return side can bias the signal colder and may become intermittent with heat or humidity.
Check 5: Signal wire shorted to reference voltage or another powered circuit. A melted or pinched harness can place excessive voltage on the input even with a working sensor.
Check 6: PCM calibration, connector or input fault. This is the final branch after the temperature element and complete circuit have been proven at the controller.
Use the test results to choose the repair. A position in this list does not prove that a part has failed.
Illustrative diagnostic pattern
This illustrative graph explains a diagnostic pattern. Use the vehicle-specific procedure to interpret it.
After the vehicle has sat long enough to equalize, turn the key on before starting and compare intake-air temperature with ambient air and engine coolant temperature. This graph is illustrative; use the vehicle's specified soak time and allowable difference.
A known-good IAT begins near the other cold-soaked temperature readings, then rises gradually from engine-bay heat and airflow after startup. The values do not need to be identical, but they should make physical sense.
The P0113 trace stays near an extreme cold default while ambient and coolant are ordinary. An intermittent open can jump instantly between a believable value and the cold limit when the connector or harness moves.
If scan data is implausibly cold, inspect the connector before unplugging it, then use the factory-approved resistor, simulator or back-probe test. If the displayed temperature responds, the sensor or its connection is suspect; if it does not, trace the signal and return to the computer.
Diagnostic steps
So here is the order to actually test this, cheapest and most likely first.
Step 1. After a proper cold soak, is IAT 1 implausibly colder than ambient and coolant? Save every code and freeze frame before clearing anything. Compare all temperatures key-on engine-off and confirm the scan tool is showing the correct IAT parameter; an ordinary reading now points toward an intermittent fault or enabling condition.
Step 2. Is the correct sensor fully connected with clean, tight and seated terminals? Inspect before disconnecting so a pushed-out pin is not accidentally reseated. Check connector locks, wire strain, corrosion and harness routing, especially when IAT is integrated into another airflow or pressure sensor.
Step 3. Does scan temperature respond correctly to the approved resistor or simulator test? Use only the factory test value and pinout. Never short a five-volt reference directly to ground. If the displayed temperature moves to the specified value, the computer and most of the harness can see a valid resistance.
Step 4. Do signal, return, continuity and short-to-voltage tests meet specification? Test both conductors end to end and under light harness movement, then load-test the return where the procedure requires it. Check shared references before condemning an integrated MAF, MAP or pressure sensor.
Step 5. Does the correct signal voltage and temperature relationship reach the PCM pins? Prove the signal at the controller under the same condition. If it is correct there but scan data remains wrong, verify connector fit, grounds and software before considering the rare PCM input fault.
Start with the impossible temperature, preserve the connector evidence, and prove where the pull-up circuit opens before replacing an integrated sensor.
Illustrative repair budgets
These are illustrative US parts budgets with labor shown separately. Diagnosis, taxes, access and additional repairs can change the total.
Connector terminal or pigtail repair: 10 to 180 dollars in parts, plus about 1.0 hours of labor. A pushed-out or spread terminal may need a correct terminal repair rather than a complete sensor.
Accessible signal or return wiring repair: 10 to 400 dollars in parts, plus about 1.5 hours of labor. Cost rises when the open is inside a wrapped engine harness or shared splice.
Standalone intake-air-temperature sensor: 15 to 140 dollars in parts, plus about 0.5 hours of labor. Confirm the connector and response test first because many standalone sensors are easy to replace and easy to misdiagnose.
Integrated MAF, MAP or charge-pressure sensor: 60 to 550 dollars in parts, plus about 1.0 hours of labor. Replace the combined assembly only after proving its IAT element failed while its wiring remained intact.
PCM connector, software or module repair: 0 to 1600 dollars in parts, plus about 2.0 hours of labor. The rare final branch after the correct resistance and voltage relationship is proven at the controller.
Test the connector and circuit response before replacing an integrated sensor.
Sources and application limits
This legacy guide has not yet had a page-specific source list added. Check the factory service information for your exact year, make, model and engine before acting on a test or specification.