Draft guidance: awaiting Claude spot-check, qualified-mechanic review and named-editor approval. Do not use a fault code alone to replace parts.

P0113: Intake-air temperature sensor 1 circuit high input

The ECU is seeing abnormally high signal voltage from the IAT circuit.

What P0113 means

The ECU is seeing abnormally high signal voltage from the IAT circuit. On the usual sensor design, this appears as implausibly cold intake air and commonly indicates an open or disconnected circuit.

Can I still drive?

Arrange diagnosis promptly and avoid demanding journeys. A short, gentle trip may be reasonable when the warning is steady amber and drivability is normal. Stop if the lamp flashes, the engine runs badly or stalls, power loss is unsafe, or smoke, overheating, a red warning or a strong fuel/burning smell appears.

Symptoms

  • Engine-management light, sometimes with no other obvious effect.
  • Difficult starting.
  • Hesitation or lower power.
  • Increased fuel consumption.
  • Fallback operation.

Common causes

  • Unplugged sensor.
  • Broken wire or open circuit.
  • Backed-out, spread or corroded connector terminal.
  • Internally open sensor.
  • Signal wire shorted to its voltage supply.
  • Fault in a combined MAF/MAP/IAT assembly; ECU failure is rare.

Safe first checks

  • Check whether the connector was disturbed during recent air-filter or intake work. With the ignition off, confirm that the plug is latched and accessible terminals are not loose, green with corrosion or pushed backwards. Cold-soak live data showing an extreme low-temperature substitute value supports an open-circuit diagnosis but does not identify which part has failed.

Typical UK fix cost

Estimated diagnostic charge: £60–£130. Estimated total for a separate sensor or straightforward terminal repair: £90–£230; for an integral MAF/MAP/IAT unit: £180–£500. Wiring work may be £130–£400+. Premium assemblies and buried loom damage may cost more.

Related models

This is a generic OBD-II code used across many makes and models. The exact test thresholds, component layout and repair route vary by engine and manufacturer, so check vehicle-specific technical information before ordering parts.

Related fault codes

Sources

A diagnostic trouble code identifies a system or circuit to investigate. It does not prove that a named part has failed. Preserve freeze-frame data and seek a vehicle-specific diagnosis before clearing the code.