Description of DTC P1407
OBD2 Error Codes

P1407 (Volkswagen, Audi, Skoda, Seat) Exhaust gas recirculation (EGR) temperature sensor – signal level too low

P1407 – OBD-II Trouble Code Technical Description

Trouble code P1407 indicates that the temperature sensor signal in the exhaust gas recirculation (EGR) system is too low in Volkswagen, Audi, Skoda, Seat vehicles.

What does the fault code mean P1407?

Trouble code P1407 indicates that the vehicle's Exhaust Gas Recirculation (EGR) temperature sensor is transmitting too low a signal. The EGR temperature sensor typically measures the temperature of the gases passing through the exhaust gas recirculation system and relays this information to the engine control module. A signal that is too low can indicate a variety of problems, such as a malfunctioning sensor, improper wiring or corrosion in the wires and connectors, or even a problem with the EGR system itself. This may result in poor engine performance, increased emissions and loss of fuel efficiency.

Fault code P1407

Possible reasons

Some possible reasons for the P1407 trouble code:

  • Faulty EGR temperature sensor: The sensor itself may be damaged or fail, causing the EGR system's gas temperatures to be incorrectly read.
  • Incorrect sensor connection: Incorrect connection of the EGR temperature sensor or a break in the wires can lead to erroneous signals.
  • Corrosion or oxidation of wires and connectors: Damaged or oxidized wires and connectors can cause poor contact and an incorrect sensor signal.
  • Problems with the exhaust gas recirculation system: Improper functioning of the EGR system itself, such as a clogged or stuck EGR valve, can cause the temperature of the gases to decrease and therefore the signal from the temperature sensor to be too low.
  • Problems with the engine control module: Incorrect data coming from the engine control module can lead to incorrect interpretation of the EGR temperature sensor signal.
  • Other factors: In some cases, the P1407 code can be caused by mechanical damage to the system or problems with other components that affect the operation of the EGR system, such as pressure sensors, vacuum lines, etc.

What are the symptoms of a fault code? P1407?

The following symptoms may occur with DTC P1407:

  • Loss of engine power: Reduced engine performance may occur due to improper operation of the exhaust gas recirculation (EGR) system and low gas temperatures.
  • Unstable idle: Low gas temperatures in the EGR system can affect the engine's idle speed, causing it to become unstable.
  • Increased emissions of harmful substances: If the EGR system is ineffective, nitrogen oxide (NOx) emissions may increase, which may cause environmental compliance problems.
  • Flashing or lighting of the Check Engine indicator: When a P1407 code is detected, the vehicle's control system may turn on the Check Engine light on the dashboard, which may flash or stay on depending on how severe the problem is.
  • Deterioration in fuel economy: Improper operation of the EGR system can result in inefficient use of fuel and, as a result, poor fuel mileage.

It is important to note that symptoms may vary depending on the specific operating conditions of the vehicle and the nature of the problem.

How to diagnose a fault code P1407?

To diagnose DTC P1407, it is important to follow these steps:

  1. Checking the indicators on the instrument panel: If the P1407 code is present, the Check Engine light will illuminate on the instrument panel. Check its condition and note any other signs of trouble, such as blinking lights or other warning messages.
  2. Using the diagnostic scanner: Connect the diagnostic scan tool to your vehicle's OBD-II port and read the trouble codes. Make sure code P1407 is in the list of codes found.
  3. Checking EGR system parameters: Using a scan tool, check the exhaust gas recirculation (EGR) system parameters, such as gas temperature, temperature sensor readings, and any other available parameters. If the values ​​are not within normal or expected ranges, this may indicate a problem.
  4. Checking wiring and connections: Inspect the wiring and connectors connecting the EGR temperature sensor to the central control unit (ECU). Check that the wiring is not damaged, the connectors are securely connected and there are no signs of corrosion.
  5. Temperature sensor testing: If necessary, test the EGR temperature sensor using a multimeter or special diagnostic equipment. Check its resistance at different temperatures and compare with expected values.
  6. Checking the EGR system for blockages: Check the exhaust gas recirculation (EGR) system for blockages or blockages that may be preventing gases from circulating properly.

If you have difficulty or are unsure of your diagnostic skills, it is recommended that you contact a professional auto mechanic for a diagnosis.

Diagnostic errors

When diagnosing DTC P1407, the following errors may occur:

  • Ignoring other fault codes: If there are multiple trouble codes, the mechanic may focus only on the P1407 code, ignoring possible related problems.
  • Misinterpretation of symptoms: Some symptoms, such as rough engine performance or poor performance, may be misinterpreted as signs of a faulty EGR system when the cause may lie elsewhere.
  • Incorrect diagnosis of temperature sensor: If the problem is related to the temperature sensor, the error may be misinterpretation of the sensor test results or misinterpretation of its readings.
  • Unsatisfactory wiring check: Failure to inspect wiring or connectors sufficiently may result in missing breaks, corrosion, or other damage that may be causing the problem.
  • Incorrect component replacement: Incorrect diagnosis can lead to replacement of unnecessary parts or components, which can lead to additional costs and ineffective debugging of the problem.

To avoid these errors, it is important to closely monitor all symptoms, perform comprehensive diagnostics, and use the correct methods and tools to inspect EGR system components and related items.

How serious is the fault code? P1407?

Trouble code P1407 is not typically critical to driving safety, but may affect engine performance and vehicle efficiency. A low exhaust gas recirculation (EGR) temperature sensor signal can cause the EGR system to malfunction, which in turn can lead to increased emissions of harmful substances into the environment and poor engine performance.

Although the vehicle may continue to run with this trouble code, it may result in poor fuel economy, rough engine operation, and other problems. If the P1407 code is not cleared, it may cause additional damage to the EGR system components and increased engine wear. Therefore, it is recommended to diagnose and repair this fault as soon as possible to avoid more serious problems in the future.

What repair will help eliminate the code? P1407?

To resolve the P1407 code, follow these steps:

  1. Checking the EGR temperature sensor: First check the Exhaust Gas Recirculation (EGR) temperature sensor to see if the signal is too low. If the sensor is truly faulty, it needs to be replaced.
  2. Checking wiring and connections: Check the wiring and connections associated with the EGR temperature sensor for corrosion, overheating, opens or shorts. If problems are found, they must be corrected or replaced.
  3. Checking the Exhaust Gas Recirculation (EGR) System: Check the EGR system itself for blockages, leaks or other problems that could cause the temperature level to drop.
  4. Updating the software: Sometimes updating the Engine Control Module (ECM) software can help resolve a low EGR temperature sensor problem.
  5. Checking and replacing the EGR valve: If all other components are normal, the Exhaust Gas Recirculation (EGR) valve itself may be faulty and should be checked for faults and replaced if necessary.

After carrying out the above steps, you should clear the fault code and perform a test run to be sure that the problem has been resolved. If the code is not returned, the problem is considered resolved.

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