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Ram Cummins P0470: Exhaust Pressure Sensor Malfunction

P-Code P0470 (FMI N/A) — Exhaust Pressure Sensor Malfunction

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Quick Answer

P0470 means the exhaust backpressure sensor is reporting an implausible reading on a 6.7L Cummins. It's a Medium severity fault - clear the sense tube before assuming the sensor itself has failed.

Overview: Ram Cummins P-Code P0470

ProfessionalDieselRepair.com resolves a good share of these with nothing more than a length of stiff wire and some brake cleaner - the tube clogs long before the sensor itself typically fails.

Repair Snapshot

Time

1 - 2 Hours

Difficulty

Intermediate

Parts Cost

$60 - $300

Dealer Labor

$350+

Tools Required

  • Chrysler wiTech
  • Diesel Laptops Diagnostic Software
  • Multimeter
  • Mechanical Wire

What P-Code P0470 Means

P0470 means the exhaust backpressure sensor's signal is implausible or malfunctioning, which the PCM relies on to manage EGR, DPF regen, and turbo control strategies. On the 6.7L Cummins this usually doesn't cause an immediate drivability problem but can throw off several related emissions functions until fixed.

Symptoms Drivers Notice

  • Check engine light with no immediate power loss
  • Possible inconsistent DPF regen behavior
  • Companion EGR or exhaust pressure-related codes
  • No noticeable performance change in many cases

Most Likely Root Causes

Carbon-clogged exhaust pressure sense tube

Common

A mechanical restriction inside the small sense line itself, not the sensor - soot packs the narrow tube and produces an implausible reading.

Corroded sensor electrical connector

Occasional

An electrical/wiring fault that produces an inaccurate reading despite the pressure tube being clear.

Failed exhaust pressure sensor

Occasional

A genuine sensor component failure, confirmed only after ruling out the sense tube and connector.

Common Misdiagnoses (Don't Waste Parts)

Replacing the exhaust pressure sensor without checking the sense tube first

Why it happens: The sensor is the named fault component.

Do this instead: This is a parts-cannon shortcut - clear the tube with mechanical wire and brake cleaner before assuming the sensor itself has failed.

Ignoring the fault since drivability seems unaffected

Why it happens: No obvious performance change makes it feel low priority.

Do this instead: Address it promptly anyway, since the PCM relies on this sensor for EGR and DPF regen strategy decisions.

Master Tech Commentary

Mechanic's Notes

ProfessionalDieselRepair.com tip: clear the sense tube with mechanical wire before condemning the sensor itself. A plugged tube produces the exact same malfunction code as a bad sensor, and it's a much cheaper fix.

Step-by-Step Diagnostic Procedure

  1. Step 1: Inspect the exhaust pressure sensor's sense tube for carbon blockage, since a plugged tube is a common cause of an implausible reading.
  2. Step 2: Check the sensor's electrical connector for corrosion or a loose pin.
  3. Step 3: Backprobe the sensor signal wire and check for a stable reference voltage at key-on with the engine cold.
  4. Step 4: Compare the sensor's reading against expected values at idle versus under load using live data.
  5. Step 5: If the tube and connector check out clean, test the sensor itself against OEM specification since an internal component failure produces this exact malfunction code.

Live Data & Freeze-Frame Tips

Compare exhaust pressure readings at idle and under load. A tube or connector issue typically produces a flat, unresponsive reading regardless of RPM or load, while a genuine restriction climbs proportionally with exhaust flow.

Safety Warnings

  • Let the exhaust system cool fully before disconnecting the sense tube.
  • Wear eye protection when clearing soot from the tube.

When to Limp In vs Tow

Not necessary - this fault doesn't typically affect drivability, though it should be addressed to ensure accurate exhaust monitoring for EGR and DPF strategies.

Prevention Tips for Fleets & Owner-Operators

  • Inspect the exhaust pressure sense tube at scheduled service intervals.
  • Address any exhaust pressure-related warning promptly rather than letting inconsistent readings persist.
  • Keep sensor connectors clean and properly seated during any exhaust-related service.

Related Fault Codes

P0401

EGR flow insufficient, a related emissions system fault that can be affected by inaccurate exhaust pressure data.

P2463

DPF restriction - soot accumulation, which can be affected by an unreliable exhaust pressure reading used in regen strategy.

Frequently Asked Questions

Can I keep driving with P0470 active?

Yes - this fault doesn't typically affect performance, though it should be fixed so the PCM can properly manage EGR and DPF regen strategies.

How do I reset this code without a scan tool?

It may clear temporarily with a battery disconnect, but it will likely return since the underlying tube or connector issue hasn't been addressed.

Does this code trigger a derate?

No, not typically - this is a monitoring accuracy issue rather than a severe restriction fault.

Is this always a clogged tube?

Most of the time, yes, but always verify the connector and sensor itself if clearing the tube doesn't resolve the fault.

How much does this repair cost?

Clearing the tube is essentially free if done during a routine visit. A full sensor replacement typically runs $150-$300 including labor.

Why does this happen more on trucks with heavy idle time?

Extended idling produces more soot at lower exhaust velocity, which is more likely to settle and pack into the narrow sense tube over time.