P00A9: Intake Air Temperature Sensor 2 Circuit Intermittent/Erratic Bank 2

Intake air temperature sensor 2 for bank 2 is the second air temperature sensor in the intake path of the second cylinder bank, for example in the intake manifold behind the charge air cooler on engines with two intake paths. For P00A9, the signal jumps faster than a real temperature can change, which typically points to a loose contact. No manufacturer description naming this exact code was found. Bank 2 codes occur only on engines with two separate intake or charge-air paths, one per cylinder bank.

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

Bank 2 is the side without cylinder 1, so it only exists on V or boxer engines.

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 P00A9 means

P: Powertrain: engine and transmission
0: Generic code: same on every make
0: Subsystem depends on the code range
A9: Specific fault in that system

Frequently asked questions

Can I keep driving with code P00A9?

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

What causes code P00A9?

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.