P0113: Intake Air Temperature Sensor 1 Circuit High
P0113 comes with a built-in absurdity that makes it easy to understand: when this circuit fails, the computer concludes the air entering your engine is minus 40 degrees. In Australia. In summer. The fuelling adjustments it makes for that imaginary Antarctic intake are why a tiny sensor fault produces noticeably clumsy running, and why the fix is usually electrical rather than a parts problem.
What P0113 actually means
The intake air temperature sensor is a thermistor: its resistance falls as air warms. The computer reads that resistance as a voltage. A broken wire, unplugged connector or failed element sends the voltage to its maximum, and maximum voltage on this circuit translates to the coldest reading on the chart, about minus 40. The computer knows that's implausible next to the coolant temperature and stores P0113: Intake Air Temperature Sensor 1 Circuit High Input. "High" describes the voltage, not the temperature.
Can you keep driving?
Severity: 2 out of 5. Yes. The computer substitutes an estimated value and the engine runs, typically slightly rich, with mildly worse economy and occasionally a lazy cold start. Nothing about this code strands or damages; it's an errand, not an emergency.
What causes P0113 (most likely first)
- An unplugged or half-seated connector. The genuinely embarrassing cause, and common after any air filter change or engine bay work. Check it first, especially if the code appeared within a week of someone being in there.
- Broken wiring. The IAT loom flexes with the intake tract every time the engine rocks, and conductors fatigue where the harness bends.
- A corroded connector. Green pins add resistance; resistance reads as cold air.
- A failed sensor element. Real but the least common, partly because there's so little inside to fail.
One structural note that decides your shopping: on many engines the IAT lives inside the MAF sensor housing. On those, a genuinely dead element means a MAF assembly, which changes the price bracket, and also means this code keeps company with P0101 when the shared connector is the culprit.
Symptoms you'll notice
Often nothing beyond the light. Perhaps slightly rich running, a whiff of fuel at cold idle, marginally worse economy. This code's main cost is the inspection lamp, not the driving experience.
What it costs to fix in Australia
| Repair | Typical cost (AUD) |
|---|---|
| Reseating a connector | $0 |
| Connector clean or repair | $50–150 |
| Standalone IAT sensor, fitted | $60–180 |
| MAF assembly (integrated IAT), fitted | $150–450 |
The honest ordering here saves real money: wiggle-test the connector and wiring with the engine running and the live temperature reading on screen before buying anything. If the reading jumps from minus 40 to something sane mid-wiggle, you've found a $0 fault with a $0 diagnostic method.
P0113 on Australian cars
Hilux and Triton IATs live inside the MAF housing, so their P0113s arrive with the buying note above attached. Falcons and Commodores mostly run standalone sensors that cost less than a tank of fuel. The Australian angle is heat cycling: engine bays that see 70-plus degrees every summer afternoon age connectors and insulation faster than the sensor element itself, which is exactly why the electrical causes dominate here.
Will P0113 fail rego or a roadworthy?
The lamp fails a NSW pink slip on cars over five years old and Victorian or Queensland certificates at sale. Given the fix is frequently free, this might be the least justifiable code in the library to carry into an inspection.
How to read and clear P0113
Read the code, then look at the intake temperature value in live data; minus 40 confirms the open circuit story instantly, and comparing it against coolant temperature settles it. Wiggle-test, fix what moves the number, clear, done. The sibling low-input code, P0112, means the opposite fault, a shorted circuit reading impossibly hot, and the same connector-first logic applies. Everything else is in the fault code library.
P0113 FAQ
Why does my scanner show intake temp of minus 40?
Because the circuit is open and the computer maps maximum voltage to its coldest table entry. The reading is the fault's signature, not a thermometer error.
Can I drive with P0113?
Yes, for as long as it takes to get around to it. Slightly rich running is the whole penalty.
Is the IAT part of the MAF sensor?
On many engines, yes, integrated in one housing. On those cars a dead element means replacing the MAF assembly; a wiring fault still costs almost nothing.
What's the difference between P0112 and P0113?
Opposite electrical faults on the same circuit: P0113 is high voltage reading impossibly cold, P0112 is low voltage reading impossibly hot. Both usually trace to wiring before sensor.
Related codes: P0101 · P0128 · P0171 · Full fault code library
A fault code is a starting point, not a diagnosis. The same code can have different causes on different vehicles, and any costs shown are typical Australian ranges only. Always have the fault confirmed by a qualified mechanic before buying parts or booking repairs.