The Ambient Air Temperature Sensor measures the temperature outside the passenger compartment and is usually mounted inside or near the front bumper. The sensor provides input to automatic HVAC systems to help control the interior temperature of the automobile.

The sensor should mount under the driver side bumper in front of the tire.

Symptoms of a Bad Coolant Temperature Sensor If your vehicle starts to use a lot more gasoline than usual, or black smoke is starting to come from the exhaust pipe, these are indicators that the coolant temperature sensor in your vehicle could be defective, and needs to be replaced.

Inconsistent cooling Another symptom of a bad or failing ambient temperature sensor is inconsistent cooling. If the ambient temperature sensor fails or is sending out an inconsistent signal, then the AC system may have trouble maintaining cool and comfortable cabin temperatures.

As far as the ambient sensor, that is not the MFA ambient temp sensor. This is for the A/C to make sure the compressor does not turn on on if the Sun Load is above a certain threshold to protect the compressor. This one, you can bypass if you wish. You just need to jump a wire across the sensor.

To clean the intake air temp sensor: remove the duct from the throttle body and spray the sensor. Two or three shots will remove almost any oil-based contamination from it. The stuff dries fast, almost instantly. The can warns that the fumes are highly flammable.

Symptoms of a Faulty Mass Air Flow Sensor

• The engine is very hard to start or turn over.
• The engine stalls shortly after starting.
• The engine hesitates or drags while under load or idle.
• Hesitation and jerking during acceleration.
• The engine hiccups.
• Excessively rich or lean idling.