P0419 code meaning
AIR System Control B Circuit
Powertrain system Generic code P04xx codes Check engine light
What P0419 means
After a cold start the secondary air (AIR) pump blows fresh air behind the exhaust valves so that unburnt fuel burns off and the catalyst heats up faster; a shut-off valve opens the path and stops exhaust from flowing back. Control B is the drive circuit of a second pump or pump relay, found only on systems with two pumps or relays, for example large V engines with one pump per bank. It is checked like P0418 by comparing the driver's feedback with its commanded state. No manufacturer document available to us describes P0419 specifically; Pierburg's fault table lists it as relay B with the same remedies as relay A.
P0419 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyEasy, DIY possible
- Typical labor0.2 to 2.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P0419
- Check engine light on
- Second pump does not run
- Secondary air readiness not set (emissions test)
- Driving normal
Common causes of P0419
- Most likelyPump relay B faulty
- Most likelyWire or connector to relay B faulty
- PossibleFuse or supply
- Less likelyPump B blocked (consequential damage)
- Less likelyEngine module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Air pump relay bSecondary air pumpRelay wiringEngine control module
What each part of P0419 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 4 | Area: auxiliary emission controls (catalytic converter, EGR, EVAP). |
| 19 | The exact fault in that area. |
What to do next
- Note P0419 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0419
What does P0419 mean?
P0419 means "AIR System Control B Circuit". After a cold start the secondary air (AIR) pump blows fresh air behind the exhaust valves so that unburnt fuel burns off and the catalyst heats up faster; a shut-off valve opens the path and stops exhaust from flowing back. It is a generic code, so it means the same on every make.
Is it safe to drive with P0419?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P0419 fail an emissions test?
Yes, it can. P0419 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0419 to fix?
Difficulty: easy. A typical repair takes 0.2 to 2.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0419 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.