What causes fault code P047C?

• Most likely: Faulty exhaust pressure sensor (internal electrical failure) • Likely: Damaged wiring harness (short to ground on signal wire) • Possible: Corroded or loose connectors at the sensor • Rare: Internal Engine Control Unit (ECU) fault

How do you fix fault code P047C?

STEP 1: Inspect the connector for sensor B for corrosion or loose pins. Ensure vacuum lines or pressure tubes to the sensor are not clogged. STEP 2: Measure reference voltage from the ECU. The sensor should have exactly 5.0V supply and a solid ground. Check signal wire; if 0V is present while connected, suspect short to ground. STEP 3: Use a diagnostic scanner to monitor 'Exhaust Pressure' live data. If the value is stuck at 0, unplug the sensor. If the reading jumps to max (e.g., 4.5V+), the wiring is healthy and the sensor is faulty. STEP 4: Replace the exhaust pressure sensor. Some vehicles may require adaptation reset using a scan tool after replacement.

Powertrain (Engine & Gearbox)Standard EOBD

P047C - Exhaust Pressure Sensor B - Circuit Low

Q: What are the symptoms of fault code P047C?

• Check engine light on (MIL) • Reduced engine performance (Limp mode) • Increased fuel consumption • Improper DPF regeneration cycles • Vehicle will fail emissions inspection

Last updated:1 February 2026

Related:Avgastryckgivare B, Diesel Particulate Filter (DPF), EGR Valve, Wiring Harness, Engine Control Module (ECM)

System

Powertrain (Engine & Gearbox)

Related Fault Codes

P0400

Exhaust Gas Recirculation Flow Malfunction

P0401

Exhaust Gas Recirculation (EGR) Flow Insufficient Detected

P0402

Exhaust Gas Recirculation Flow Excessive Detected

P0403

Exhaust Gas Recirculation (EGR) Control Circuit

Technical Description

P047C is stored when the Engine Control Module (ECM/PCM) detects an electrical signal from the Exhaust Pressure Sensor 'B' that is below the expected operating range (typically below 0.2V to 0.5V). This sensor monitors backpressure in the exhaust system, which is critical for EGR flow control and DPF monitoring. A 'low' signal typically indicates a short to ground or an open circuit, preventing the ECM from accurately calculating boost pressure or EGR rates.

Possible Causes

Faulty exhaust pressure sensor (internal electrical failure)

Damaged wiring harness (short to ground on signal wire)

Corroded or loose connectors at the sensor

Internal Engine Control Unit (ECU) fault

Symptoms

Check engine light on (MIL)

Reduced engine performance (Limp mode)

Increased fuel consumption

Improper DPF regeneration cycles

Vehicle will fail emissions inspection

Do you also have
other fault codes?

See how P047C connects with your other fault codes. Our advanced analysis tool identifies causal relationships and root causes directly.

Analyze multiple codes

P047C - Exhaust Pressure Sensor B - Circuit Low

Related Fault Codes

Technical Description

Possible Causes

Symptoms

Recommended Solution

Workflow

Mechanic's Tip

Do you also have
other fault codes?

P047C - Exhaust Pressure Sensor B - Circuit Low

Related Fault Codes

Technical Description

Possible Causes

Symptoms

Recommended Solution

Workflow

Mechanic's Tip

Do you also have other fault codes?

Do you also have
other fault codes?