P0127Generic code

P0127 Code: Intake Air Temperature Too High

The P0127 code means the intake air is too hot, which is typical of turbocharged engines with a clogged intercooler or of a temperature sensor that reads wrong.

Severity
Medium
Can I keep driving?
Yes, but with caution
Estimated cost
$30 to $600
Difficulty
Medium
System
Air and Fuel
Applies to
All OBD2 vehicles

Updated Reviewed by Renzo Chacca

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What the P0127 code means

On turbocharged engines, the air heats up as it is compressed and the intercooler cools it before it enters the engine. The computer watches the air temperature after the intercooler. If it exceeds the limit (often between 60 and 80 °C, or 140 to 176 °F, depending on the manufacturer) for a period of time, the P0127 code is stored and the computer may reduce turbo boost to protect the engine.

It can also show up on naturally aspirated engines when the IAT sensor reads wrong or when the intake duct draws hot air from the engine bay. Test the IAT sensor as part of the diagnosis.

P0127 code symptoms

  • Check engine light on.
  • Loss of power, especially in hot weather and under load.
  • Detonation (knocking or pinging) when you accelerate.
  • Turbo protection mode.

Likely causes of the P0127 code

  1. Intercooler dirty on the outside, with insects, leaves or mud blocking the airflow.
  2. Intercooler clogged on the inside with oil from the turbo or the breather.
  3. Out-of-calibration air temperature sensor.
  4. Intake duct that draws hot air from the engine bay.
  5. Cooling fan that does not work on vehicles where it helps the intercooler.

How to diagnose the P0127 code step by step

  1. Read the air temperature in live data. With a cold engine it should match the ambient temperature.
  2. Inspect and clean the intercooler on the outside.
  3. Check for oil in the intercooler hoses. It points to a leaking turbo or breather.
  4. Compare on the road the air temperature with the ambient. On a healthy intercooler it should not exceed it by more than 20 to 30 °C (36 to 54 °F).
  5. Measure the sensor resistance and compare it with the manufacturer table.

How to fix the P0127 code

  • Clean the intercooler on the outside with low-pressure water.
  • If it has oil inside, clean or replace it and fix the cause of the oil.
  • Replace the sensor if it reads wrong.
  • Correct the intake duct.
  • Clear the codes and verify on the road.

Technical reference data

  • Air temperature after the intercooler: ambient plus 10 to 30 °C (18 to 54 °F) in normal driving.
  • Typical code limit: 60 to 80 °C (140 to 176 °F).
  • Values are approximate.

Brand-specific notes

The P0127 code shows up mostly on turbo diesels and on pickups that drive on dusty roads, where the intercooler gets clogged on the outside.

P0127 on Ford

On Ford turbo diesels, this code shows up mostly on vehicles driven on dusty roads, where the intercooler clogs on the outside.

P0127 on Volkswagen

On Volkswagen turbo diesels, this code shows up mostly on vehicles driven on dusty roads, where the intercooler clogs on the outside.

P0127 on Nissan

On Nissan turbo diesels, this code shows up mostly on vehicles driven on dusty roads, where the intercooler clogs on the outside.

P0127 on Toyota Hilux

On the Toyota Hilux, this code shows up mostly on trucks driven on dusty roads, where the intercooler clogs on the outside.

Frequently asked questions about P0127

Can I drive with a P0127 code?
With caution. The engine may limit power, and in hot weather there is a risk of detonation.
Can P0127 damage the engine?
Yes, if very hot air causes continuous detonation. That is why the computer limits the turbo.
Do I have to replace the intercooler?
Not always. Many times cleaning it on the outside is enough.
How much does it cost to fix P0127?
Roughly $30 to $600, from a cleaning to a new intercooler.
What does the P0127 code mean?
It is a generic OBD2 code that means the intake air temperature is higher than the computer allows. On turbo engines it usually points to a dirty or clogged intercooler.
What is the most common cause of P0127?
An intercooler clogged with dirt on the outside or with oil on the inside. A sensor that reads wrong is the other common reason.

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