P0112 on Toyota Corolla E170: Intake Air Temperature Sensor 1 Circuit Low Input
Short answer: P0112 means “Intake Air Temperature Sensor 1 Circuit Low Input”. The car’s computer has found a fault in the Engine system and turns on the Check engine light (MIL). First check: read the code and freeze-frame data with an OBD-II scanner.
Standard OBD-II code Same meaning on all cars (SAE J2012). Not checked against this car’s factory manual.
- Code
- P0112
- System
- Engine
- Dashboard light
- Check engine light (MIL)
- Applies to
- Generic OBD-II meaning. Not every code is used by this car.
- Confidence
- medium (generic OBD-II definition, not checked against the factory manual for this car)
- Source
- obd-codes.com
Symptoms and when it is set
- Check engine light on
- There may be no noticeable symptoms of a
- P0112
- Indicator Lamp). However, a emissions test may reveal higher Nox readings depending
- On the type of IAT failure. Or the engine may ping under load, depending on the
- Type of IAT failure
Likely causes
- Usually the P0112 is caused by a bad IAT (internally shorted or open or otherwise damaged)
- But it could also be
- No reference voltage to the IAT sensor due to an open wire
- Excessively high intake air temperatures
- Short to ground on signal circuit
- Damaged IAT connector
- Bad PCM
What to check, in order
- Read the code and freeze-frame data with an OBD-II scanner
- Check the connector and wiring of the part named in the code
- Test the part with scanner live data or a multimeter, using the values in the repair manual
- Fix the cause, clear the code and test-drive
Related on this car
Same code on other cars
- P0112 · Toyota Passo (1st gen)
- P0112 · Toyota Corolla (10th gen, E140)
- P0112 · Honda City (5th gen, GM2)
- P0112 · Honda Civic (10th gen, FC)
- P0112 · Suzuki Wagon R (Pakistan, K10B)
- P0112 on all cars compared
Clearing the code does not fix the fault. If it comes back, the problem is still there. For brakes, airbags and steering, see a trained mechanic.