Fault code P0071 – a step-by-step guide to diagnosing and fixing it

Error code P0071 is displayed and the check engine light is on - what does this mean?

The OBD system detects a malfunction in the intake air temperature sensor (IAT) in the "Ambient Air Temperature Sensor Range/Performance" area. This DTC P0071 indicates that the ambient air temperature sensor is providing values outside the expected range or is not functioning properly.

What can cause this error code?

• Defective intake air temperature sensor (IAT)
• Damaged or corroded cable connections to the sensor
• Loose or dirty plug connections
• Short circuit or open wire in the sensor cable
• Defective engine control unit (ECU)
• Dirty or clogged air filter
• Faulty ground connection of the sensor

What symptoms occur in parallel with fault code P0071?

• Starting problems: The vehicle starts poorly or requires several attempts
• Uneven idling: The engine runs unevenly at idle speed
• Increased fuel consumption: Noticeably higher consumption than usual
• Loss of power: Reduced engine power, especially when the engine is cold
• Black smoke: Dark exhaust fumes from the exhaust pipe
• Check engine light: Permanently lit or flashing warning light

How can the problem with error code P0071 be rectified?

• Repairing trouble code P0071 requires a systematic approach to identifying the source of the fault.
• Replace the sensor: Replace defective intake air temperature sensor with a new original part and calibrate properly
• Carry out cable repair: Locate damaged wiring, repair severed or corroded areas and re-insulate connections
• Clean plug connections: Thoroughly clean all plug contacts, remove corrosion and treat with contact spray
• Replace air filter: Replace clogged or dirty air filter with a new filter and check intake tract
• Check ground connection: Check earth cables for tight fit, remove corrosion and tighten connections
• Carry out an ECU reset: After the repair, delete the fault memory and reinitialize the engine control unit