Faulty intake air temperature sensor located in the dynamic chamber; Damaged or corroded electrical connector at the IAT sensor; Open or shorted wire in the sensor signal or ground circuit; Intake air leaks or vacuum leaks near the dynamic chamber; Contamination or oil buildup on the sensor element; PCM software issue or internal fault (less common)

DTC codes / Mazda codes / P1110

P1110 · MazdaIntake Air Temperature Sensor Signal Dynamic Chamber Circuit

P1110 on Mazda vehicles indicates that the powertrain control module (PCM) has detected an abnormal signal from the intake air temperature (IAT) sensor that is mounted in the dynamic chamber, which is the intake manifold resonance chamber. The PCM expects a voltage that corresponds to the actual air temperature, but the signal is out of range, intermittent, or implausible, so it sets this manufacturer-specific code.

SystemPowertrain

Code typeMazda specific

SeverityLow

Fix difficultyIntermediate

AreaFuel and air metering

Symptoms you may notice

Illumination of the check engine light, often with no other symptoms
Rough idle or stumbling when the engine is cold
Poor fuel economy or rich-running condition
Hesitation or lack of power during acceleration
Hard starting or extended cranking in cold weather
In rare cases, a noticeable decrease in performance when the engine is at operating temperature

Common causes, most likely first

Faulty intake air temperature sensor located in the dynamic chamber
Damaged or corroded electrical connector at the IAT sensor
Open or shorted wire in the sensor signal or ground circuit
Intake air leaks or vacuum leaks near the dynamic chamber
Contamination or oil buildup on the sensor element
PCM software issue or internal fault (less common)

How to diagnose and fix it

Use an OBD-II scan tool to read the IAT sensor voltage and compare it to ambient temperature after a cold soak.
Visually inspect the IAT sensor and its connector for damage, corrosion, or loose pins.
Check the sensor's resistance with a multimeter and compare it to the manufacturer's temperature-resistance chart.
Perform a wiggle test on the wiring harness while monitoring the IAT signal to detect intermittent faults.
Check for intake leaks around the dynamic chamber and intake manifold using a smoke machine or carburetor cleaner.
If the sensor is faulty, replace it and clear the code; if wiring is faulty, repair the affected circuit.
After repairs, verify the IAT reading matches ambient temperature and clear the code, then test-drive to confirm it does not return.

Common Misdiagnosis of P1110

A dirty or oil-contaminated IAT sensor can produce a plausible but incorrect signal that sets P1110 without triggering a hard fault, so cleaning the element often resolves the issue.
The dynamic chamber itself can develop cracks or loose mounting bolts that cause unmetered air to enter, skewing the IAT reading and setting this code.
Technicians sometimes replace the IAT sensor only to find the real problem is a chafed wire in the harness near the intake manifold, so always perform a continuity and wiggle test.
P1110 can be set by a failing thermostat that keeps the engine from reaching normal operating temperature, which affects the PCM's expected IAT values.
On some Mazda models, a weak battery or poor ground connection can cause voltage spikes that mimic an IAT sensor fault, so check the charging system first.

Can I keep driving with P1110?

The vehicle is generally safe to drive with P1110 because the fault mainly affects fuel mixture calculations and drivability, but avoid heavy acceleration or towing until it is repaired, and address it promptly to prevent potential long-term engine damage from rich running.

Tools that help

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Guidance is general and written for Mazda vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.