P047C: Exhaust Pressure Sensor B Circuit Low

The exhaust pressure sensor measures the pressure ahead of the turbine or in the manifold (Ford: turbine upstream pressure, Cummins: exhaust manifold pressure, older Ford diesels: EBP). The module uses it to calculate EGR flow, to control the variable turbine and engine braking, and to protect against overpressure. No manufacturer document available to us uses sensor B – it would be a second sensor, for example on bank 2 of a twin-turbo engine; the description mirrors sensor A. P047C means the signal voltage of sensor B is below its limit (for sensor A Ford uses 0.1 V or 0.21 V).

Medium severity. Can I keep driving?You can usually keep driving in the short term. If you smell exhaust fumes in the cabin, stop driving and ventilate the car.

Symptoms

Check engine light on
EGR and turbo control on a substitute value, possibly reduced power
Exhaust brake or warm-up flap without function

Most likely causes

Signal wire shorted to ground
5 V reference open or shorted (often shared with other sensors)
Sensor faulty internally
Connector damaged by heat or corrosion

What to check, in order

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

Look for leaks and visible damage
With the connector unplugged, check whether the signal wire is making contact with ground.
Check the connectors and wires near the exhaust
Check the live data
Test the actuator with the scanner

Good to know

Repair difficulty: medium
It can trigger limp mode.
It affects emissions.

What each character of P047C means

P: Powertrain: engine and transmission
0: Generic code: same on every make
4: Emissions
7C: Specific fault in that system

Frequently asked questions

Can I keep driving with code P047C?

You can usually keep driving in the short term. If you smell exhaust fumes in the cabin, stop driving and ventilate the car.

What causes code P047C?

The most common causes are: signal wire shorted to ground; 5 V reference open or shorted (often shared with other sensors); sensor faulty internally.

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.