Fault code P0079 – a step-by-step guide to diagnosing and fixing it

Error code P0079 is displayed and the check engine light is on - what does this mean?

DTC P0079 is recognized by the OBD system when there is a problem with the intake air temperature sensor or its circuit. This EOBD fault code relates specifically to the signal transmission between the air temperature sensor and the engine control unit, whereby the system detects an implausible or too low voltage in the sensor circuit.

What causes can this error code have?

• Defective intake air temperature sensor
• Damaged wiring to the sensor
• Corroded or loose plug connections
• Short circuit in the sensor cable
• Defective engine control unit
• Broken ground wire of the sensor
• Dirty or contaminated sensor

What symptoms occur in parallel with fault code P0079?

• Starting problems: The vehicle is difficult to start, especially in cold temperatures
• Uneven idling: The engine runs unevenly at idle speed
• Increased fuel consumption: The engine control unit cannot optimally adjust the air/fuel mixture
• Reduced engine power: Noticeable loss of power while driving
• Black smoke: Incomplete combustion leads to dark exhaust fumes
• Check engine light: The warning light is permanently illuminated

How can the problem with error code P0079 be rectified?

• Repairing trouble code P0079 requires a systematic diagnosis of the sensor components.
• Replace intake air temperature sensor completely and test with OBD scanner
• Check the wiring to the sensor and completely replace damaged cables
• Clean plug connections, treat with contact spray and connect firmly
• Use a multimeter to locate short circuits and repair defective cables
• Check sensor ground cable for continuity and re-route if interrupted
• Diagnose the engine control unit and have it replaced by a specialist workshop if defective
• Clean the air filter and intake tract to remove sensor contamination