P0473

What P0473 Means

Code P0473 indicates a high signal level from the exhaust pressure sensor. The sensor measures exhaust gas pressure, and the engine control module (DME) uses its signal to adjust emissions control and boost systems. When the signal level is high, the DME registers that voltage on the signal wire exceeds the allowed threshold, which can be caused by a faulty sensor or a short in the circuit.

The system includes a pressure sensor mounted in the exhaust tract and the electrical circuit connecting it to the DME. The sensor converts pressure into an electrical signal that the control module analyzes. A high signal level can point to a short to power or an internal sensor fault.

Symptoms

• The Check Engine light comes on in the instrument cluster.
• The engine may enter limp mode (power limitation).
• Other symptoms can depend on the specific BMW model and operating conditions.

Diagnosis and Repair

1. Read the fault codes with diagnostic equipment (ISTA, INPA) and confirm that code P0473 is active or stored.
2. Check the exhaust pressure sensor: inspect the connector and wiring for damage, corrosion, or loose contacts.
3. Check the electrical circuit between the sensor and the DME: measure resistance and check for a short to power.
4. Replace the exhaust pressure sensor if needed.
5. After repair, clear the codes and take a test drive to confirm the fault does not return.