P20A3 code meaning
Reductant Purge Control Valve A Circuit High
Powertrain system Generic code P20xx codes Check engine light
What P20A3 means
P20A3 is the high-side fault of the purge valve circuit: the line carries voltage or current where it should not. GM detects it on the 6.6 L Duramax while the low-side driver is switched on; an impedance of less than 0.5 Ω to controller power lasting 3 s triggers it as a Type A fault. Volkswagen's test for the 2014 Touareg V6 TDI (engine CNRB) looks at current instead and reports P20A3 above 3.00 A, which indicates a short across the coil or to battery positive. A driver that sees such overcurrent switches off to protect itself, so the valve no longer reverses the pump, and the line is not emptied at shutdown. P20A2 covers the opposite short to ground and P20A0 the open circuit. Look for a shorted coil, a wire touching a supply cable or a damaged connector at the supply module.
P20A3 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P20A3
- MIL on in the first trip (GM Type A)
- DEF warning and possibly further pump codes
- In frost, risk of DEF freezing in the line
Common causes of P20A3
- Most likelyValve coil with shorted windings drawing excessive current
- PossibleControl wire shorted to a battery-fed conductor
- PossibleDamaged or DEF-contaminated connector bridging pins
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Reductant purge valve
What each part of P20A3 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 0 | Area: fuel and air metering and auxiliary emission controls. |
| A3 | The exact fault in that area. |
What to do next
- Note P20A3 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 P20A3
What does P20A3 mean?
P20A3 means "Reductant Purge Control Valve A Circuit High". P20A3 is the high-side fault of the purge valve circuit: the line carries voltage or current where it should not. It is a generic code, so it means the same on every make.
Is it safe to drive with P20A3?
Drive gently and only to a workshop. With P20A3 the car can go into limp mode (reduced power) to protect itself.
Will P20A3 fail an emissions test?
Yes, it can. P20A3 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 P20A3 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P20A3 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.