GM OBD Trouble Code 25

Intake Air Temperature Sensor Error (Low Temp Indicated)

The Intake Air Temperature sensor relays the current temperature of the air entering the engine to the Engine Control Module. The ECM uses the information from this sensor to help calculate fuel delivery and spark timing.

Fault Code Description

• 25 - Intake Air Temperature Sensor error (low temp indicated, open circuit)

Symptoms

• Hard starting or running lean (lack of power)
  

Common Problems

• Code 25 is a very uncommon fault
  
• A quick test for the intake air temperature sensor circuit from the ECM would be to unplug the temp sensor and watch the intake air temperature sensor reading on the scan tool while jumping the harness side of the sensor connector. The scan readings should switch from full cold to full hot when inserting and removing the jumper from the connector.