P0099: Intake Air Temperature Sensor 2 Circuit Intermittent/Erratic Bank 1

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.

Low severity. Can I keep driving?Yes, you can normally keep driving and take it to a repair shop when convenient.

Bank 1 is the side of the engine with cylinder 1. Inline engines only have this bank.

Symptoms

Check engine light on
Usually no noticeable symptoms
Emissions test or readiness check may fail

Most likely causes

Loose contact or wire broken by movement
Sensor failing intermittently
Interference on the signal wire

What to check, in order

Start with the simplest. You can tick off each step.

With the engine cold, compare the reading with the outside temperature
Gently move the wiring with the engine running and watch whether the reading changes.
Check the connector
Measure the sensor's resistance against the manufacturer's specification
Check power and ground before replacing it

Good to know

Repair difficulty: easy
It affects emissions.

What each character of P0099 means

P: Powertrain: engine and transmission
0: Generic code: same on every make
0: Subsystem depends on the code range
99: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0099?

Yes, you can normally keep driving and take it to a repair shop when convenient.

What causes code P0099?

The most common causes are: loose contact or wire broken by movement; sensor failing intermittently; interference on the signal wire.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.