Powertrain, generic · Fuel and air metering, auxiliary emission controls
P0099 Intake Air Temperature Sensor 2 Circuit Intermittent/Erratic Bank 1
Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo
Intake air temperature sensor 2 is the second air temperature sensor in the intake path; on many turbocharged engines it sits in the intake manifold, often combined with the manifold pressure sensor, and is used to calculate cylinder filling and ignition timing. For P0099, the signal jumps faster than a real temperature can change, which typically points to a loose contact.
Likely causes
Loose contact or wire broken by movement
Sensor failing intermittently
Interference on the signal wire
Symptoms
- Check engine light on
- Usually no noticeable symptoms
- Emissions test or readiness check may fail
Repair estimate
DifficultyEasyDIY possible
Parts and labour€40–250
Time0.3–2 h
Typical range across vehicles; the real cost depends on what the testing finds.
Parts involved
intake air temperature sensor 2intake air temperature sensor wiringmanifold absolute pressure sensor
Related codes
References: law.cornell.edu, gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com.