P04AA

Exhaust Pressure Control Valve B Position Sensor/Switch Circuit Intermittent/Erratic

Severity

⚠️ Medium

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$56–167 (est.)

Symptoms

Unstable engine operation
Power Loss
Increased fuel consumption
Check Engine Light Illuminates

Causes

Open or shorted wiring harness
Poor contact in the sensor connector
Valve position sensor malfunction
Mechanical failure of the pressure control valve

How to Fix

Check the integrity of the wiring harness and connectors
Test sensor resistance and reference voltage
Clean or replace pressure control valve
If necessary, replace the position sensor

Related codes

P0401 P0402 P0403