P048C: Exhaust Pressure Control Valve A Position Sensor/Switch Circuit Range/Performance

An exhaust pressure control valve is an electrically driven flap in the exhaust with a position sensor or end-position switch, usually inside the actuator. Valve A is the first such flap; Bentley's V8 assigns A to bank 1 and B to bank 2. Documented uses are the flap behind the particulate filter of VW's and Audi's 2.0 TDI, which raises back pressure for the low-pressure EGR, and the sound flaps of Audi and Bentley. P048C means valve A's position signal is electrically valid but does not match the commanded position or the learned end positions. It is documented only on VW's and Audi's 2.0 TDI of 2009–13, together with P047F, P048A, P048B and P0401, caused by the corroded, sticking flap shaft. After replacing the actuator, the end positions must be relearned.

Medium severity. Can I keep driving?Drive as little as possible and gently. If the transmission slips or stays in one gear, go slowly to a repair shop or call for a tow truck.

Symptoms

Check engine light on
Flap without function, exhaust sound changed
VW/Audi TDI: EGR fault P0401 possible

Most likely causes

Flap or shaft corroded or coked (stiff)
End positions not relearned after replacement
Position sensor in the actuator drifting
Contact resistance in the connector

What to check, in order

Start with the simplest. You can tick off each step.

Check the fluid level and condition according to the manufacturer
Compare the reading with other engine data while varying the engine speed.
Check the transmission connector
Read the data with a transmission-compatible scanner
Measure the solenoid valve circuit
Leave opening the transmission to a specialized repair shop

Good to know

Repair difficulty: medium
It affects emissions.

What each character of P048C means

P: Powertrain: engine and transmission
0: Generic code: same on every make
4: Emissions
8C: Specific fault in that system

Frequently asked questions

Can I keep driving with code P048C?

Drive as little as possible and gently. If the transmission slips or stays in one gear, go slowly to a repair shop or call for a tow truck.

What causes code P048C?

The most common causes are: flap or shaft corroded or coked (stiff); end positions not relearned after replacement; position sensor in the actuator drifting.

Related codes

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.