P3834moderate severityPowertrain
DEF Supply Pump Pressure Low
on 2011 Audi A3 2.0L TDI I4 · FWD
What this code means
The DEF supply pump is not generating sufficient pressure to properly atomize DEF through the dosing valve.
Symptoms
- DEF system malfunction light
- Insufficient DEF dosing
- SCR efficiency reduced
- Potential derate
- Check Engine Light
- Poor atomization of DEF spray
Common causes
- DEF pump wear
- DEF filter clogged
- Air in DEF supply lines
- DEF line leak
- DEF frozen in lines or tank
Diagnostic steps
- Check DEF supply pressure with scan tool
- Inspect DEF filter condition
- Check DEF lines for air leaks
- Verify DEF line heaters working
- Test pump motor operation
Repair notes
Replace DEF supply pump or filter. Purge air from DEF lines. Check and repair DEF line heaters for cold weather operation.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1