P20DA code meaning
Exhaust Aftertreatment Fuel Supply Control Circuit High
Powertrain system Generic code P20xx codes Check engine light
What P20DA means
For the supply valve ahead of the exhaust doser, the control line reads too high, typically because it touches battery voltage or, on some drivers, an open line pulled up internally. Volvo and Mack log it as P20DA00 and list it in guide KC-2157 among the AHI module electrical faults, with the instruction to check that module's wiring and connector. A circuit stuck high leaves the valve unable to follow commands, so the control unit stops dosing and active regeneration is lost until the fault is repaired. Its siblings are P20D7 (line broken) and P20D9 (line grounded); a mechanically stuck valve sets P20DB or P20DC.
P20DA at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P20DA
- Check engine light on
- Active regeneration not possible
Common causes of P20DA
- Most likelyValve control wire shorted to a powered line
- PossibleDamaged coil in the supply valve
- Less likelyFaulty output stage in the control module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Aftertreatment fuel supply solenoid
What each part of P20DA 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. |
| DA | The exact fault in that area. |
What to do next
- Note P20DA 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 P20DA
What does P20DA mean?
P20DA means "Exhaust Aftertreatment Fuel Supply Control Circuit High". For the supply valve ahead of the exhaust doser, the control line reads too high, typically because it touches battery voltage or, on some drivers, an open line pulled up internally. It is a generic code, so it means the same on every make.
Is it safe to drive with P20DA?
Drive gently and only to a workshop. With P20DA the car can go into limp mode (reduced power) to protect itself.
Will P20DA fail an emissions test?
Yes, it can. P20DA 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 P20DA to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. This is a job for a workshop.
Will P20DA clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.