Universal Diesel · Exhaust Pressure Sensor HighMedium

Diesel P0473: Exhaust Pressure Sensor Circuit High

P-Code P0473 (FMI N/A) — Exhaust Pressure Sensor Circuit High

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Quick Answer

P0473 means the exhaust backpressure sensor circuit is reading high, often from a kinked sensing hose, chafed wiring, or a connector issue rather than a real backpressure problem.

Overview: Universal Diesel P-Code P0473

This sensor feeds several systems including EGR and regen management, so a high reading can have subtle knock-on effects even without an obvious symptom.

Repair Snapshot

Time

1 - 2 Hours

Difficulty

Intermediate

Parts Cost

$60 - $250

Dealer Labor

$350+

Tools Required

  • Multimeter
  • Wiring Diagram
  • Flashlight

What P-Code P0473 Means

P0473 means the exhaust backpressure sensor circuit is reading a higher voltage than expected, which can affect EGR, turbo, and regen management decisions since exhaust pressure feedback is used across multiple systems.

Symptoms Drivers Notice

  • Possible reduced performance if the PCM defaults to a conservative strategy
  • Check engine light
  • May affect regen timing accuracy
  • No dramatic symptom on its own in many cases

Most Likely Root Causes

Kinked or improperly routed pressure sensing hose

Common

Gives a falsely high reading independent of actual exhaust pressure.

Chafed harness near exhaust heat

Common

Heat exposure degrades insulation faster in this area.

Corroded connector

Occasional

Poor connection disrupts reliable signal transmission.

Common Misdiagnoses (Don't Waste Parts)

Replacing the sensor first

Why it happens: It's the named component.

Do this instead: Check the sensing hose routing first - it's a common, cheap-to-fix cause.

Ignoring knock-on effects on EGR/regen

Why it happens: The fault seems isolated.

Do this instead: Recognize that exhaust pressure feedback affects multiple systems.

Master Tech Commentary

Mechanic's Notes

Real-world tip: check the pressure sensing hose routing before replacing the sensor - a kinked hose can give a falsely high reading independent of sensor health.

Step-by-Step Diagnostic Procedure

  1. Step 1: Inspect the exhaust pressure sensor and its connector for damage.
  2. Step 2: Backprobe the signal wire with key on, engine off to check for a voltage pegged high.
  3. Step 3: Check the sensor's pressure hose for kinking or improper routing that could cause a false high reading.
  4. Step 4: Trace the harness for chafing near the exhaust system.
  5. Step 5: Replace the sensor only after wiring and hose have been confirmed clean.

Live Data & Freeze-Frame Tips

Compare the sensor reading against expected values at idle and under load - a consistently high value points to a hose or wiring fault.

Safety Warnings

  • Allow the exhaust system to cool fully before inspecting the sensor or hose.

When to Limp In vs Tow

Not required - the truck remains driveable.

Prevention Tips for Fleets & Owner-Operators

  • Inspect the pressure sensing hose at PM intervals.
  • Protect harness routing from direct exhaust heat exposure.
  • Address minor exhaust sensor codes before they affect other systems.

Related Fault Codes

P0472

Same circuit reading low instead of high.

Frequently Asked Questions

Does this affect my DPF regen?

It can, since exhaust pressure feedback is used in regen timing decisions.

Is the sensor usually bad?

Less often than the hose or wiring - check those first.

Can I drive with this code?

Yes, typically without major symptoms.

How do I check the hose?

Inspect its routing for kinks or improper connection at both ends.

Is this an expensive repair?

Usually inexpensive if it's a hose or wiring fix.