P2439 covers brief dropouts or jumps in the bank 2 secondary air pressure signal. No manufacturer documents this code publicly; the description rests on CARB's demand that every electrical AIR component be checked for circuit faults and rationality, together with the bank 2 sensor layout known from Audi's R8 V10 (sensor G610). Unlike with P2437 or P2438, the signal is valid most of the time, so the fault often vanishes at the workshop. Freeze-frame data, shaking the harness on the exhaust side and looking for heat-hardened insulation or green terminals are the practical steps. Bank 1 uses P2434; a lasting fault would show up as P2435–P2438 instead.
Low severity. Can I keep driving?Yes, you can keep driving, though it should be repaired: the car pollutes more at startup and may not pass an inspection.
Bank 2 is the side without cylinder 1, so it only exists on V or boxer engines.
Symptoms
- Warning lamp appears now and then
- Code returns after clearing without visible cause
Most likely causes
- Loose or corroded terminal at the bank 2 sensor
- Harness near the exhaust side brittle or chafed
- Intermittent internal sensor fault
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It affects emissions.
What each character of P2439 means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- 4: Emissions
- 39: Specific fault in that system
Frequently asked questions
Can I keep driving with code P2439?
Yes, you can keep driving, though it should be repaired: the car pollutes more at startup and may not pass an inspection.
What causes code P2439?
The most common causes are: loose or corroded terminal at the bank 2 sensor; harness near the exhaust side brittle or chafed; intermittent internal sensor fault.
Related codes
- P2434AIR System Air Flow/Pressure Sensor Circuit Intermittent/Erratic (Bank 1)
- P2435AIR System Air Flow/Pressure Sensor Circuit (Bank 2)
- P2437AIR System Air Flow/Pressure Sensor Circuit Low (Bank 2)
- P2438AIR System Air Flow/Pressure Sensor Circuit High (Bank 2)
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.