What Does P0473 Mean?
The exhaust pressure sensor A circuit is reading a voltage above the maximum expected threshold, indicating an abnormally high exhaust pressure reading or an open circuit condition. The ECM detects that the sensor signal exceeds the valid operating range. This can cause incorrect turbo boost management, forced DPF regeneration, or limp mode activation.
Common Causes
30%
Open circuit in the exhaust pressure sensor A signal or ground wire
25%
Failed exhaust pressure sensor A reading high
20%
Severely restricted exhaust (plugged DPF or catalytic converter) causing genuinely high backpressure
15%
Disconnected or corroded sensor connector
10%
ECM sensor input circuit failure
Diagnostic Steps
1
Check the exhaust pressure sensor A PID — if it reads maximum (near 5V or the maximum pressure scale), disconnect the sensor. If the reading drops to minimum, the sensor is faulty. If it stays high, there is a wiring issue.
2
Verify the sensor connector is fully seated. Inspect for backed-out pins, corrosion, or heat damage. Reconnect firmly and retest.
3
With the sensor disconnected, measure continuity of the signal and ground wires from the sensor connector to the ECM. An open on either wire will cause a high reading.
4
If the wiring and sensor check out, verify actual exhaust backpressure using a mechanical pressure gauge tapped into the exhaust. Normal backpressure at idle is 1-3 psi. Over 5-6 psi indicates a genuine restriction (plugged DPF or converter).
5
On diesel vehicles, check the DPF soot loading percentage PID. If it is above 80%, the DPF may be plugged and causing genuinely high backpressure that the sensor is correctly reporting.
Estimated Repair Cost
$100 - $2,500
Parts + labor, varies by vehicle and location
The exhaust pressure sensor A circuit is reading a voltage above the maximum expected threshold, indicating an abnormally high exhaust pressure reading or an open circuit condition. The ECM detects that the sensor signal exceeds the valid operating range. This can cause incorrect turbo boost managem...
The most common cause of P0473 (Exhaust Pressure Sensor "A" Circuit High) is: Open circuit in the exhaust pressure sensor A signal or ground wire
Typical repair costs for P0473 range from $100 to $2,500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
If caused by a genuinely plugged DPF or converter, continued driving can cause extreme exhaust temperatures, turbo damage, or in severe cases fire risk. The vehicle may go into limp mode. If a sensor/wiring fault, there is no immediate danger but turbo control will be affected. Diagnose promptly.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0473 to identify the root cause.
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Quick Info
Category
Powertrain
System
Exhaust / Turbo / DPF System
Difficulty
Type
Generic (SAE)
Recommended Tools
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