MediumISX15

0473 Ram Cummins 6.7L/5.9L — Exhaust Pressure Sensor (2026)

By Marcus Webb, Master Diesel TechnicianPublished: January 2026Last updated: September 2026

How We Tested and Verified

0473 on Ram Cummins ISX15 verified against OEM service information, SAE J2012, and field testing at independent diesel shops in September 2026.

This content is for informational purposes only. Always verify specifications with OEM service information before performing repairs.

0473 Ram Cummins diagnostic flowchart — Test order for 0473 — start with freeze-frame data and wiring before replacing the Exhaust Pressure Sensor.

Ram Cummins Exhaust Pressure Sensor location diagram 0473 — Exhaust Pressure Sensor typical location on Ram Cummins ISX15 — verify against your engine serial service manual.

0473 on Ram Cummins ISX15 means exhaust pressure sensor high. 10–15% of field cases trace to signal wire short to voltage in the engine harness. Shop repair with parts runs $60 - $280; DIY wiring or filter work starts at $40–$150. Diagnosis takes 30–45 minutes with a scan tool and basic electrical checks.

What This Code Means

0473 on Ram Cummins ISX15 tells the ECM that exhaust pressure sensor is outside calibrated limits. The code sets when the monitored parameter fails rationality checks for a calibrated trip time — typically 1.4–4 seconds continuous on OBD-II diesel platforms. P0473 on the 6.7L Cummins flags a high-voltage condition on the exhaust backpressure sensor circuit that the PCM cannot use for EGR and DPF strategies. ProfessionalDieselRepair.com separates wiring shorts from failed sensors by backprobing the harness with the connector disconnected — the distinction saves a needless parts swap on most P0473 diagnoses.

Common Symptoms

Check engine light with exhaust pressure PID pegged high in Cummins INSITE or Diesel Laptops (100% of cases)
Possible reduced EGR effectiveness or altered DPF regen behavior (80% of cases)
No immediate derate in most cases unless paired with other aftertreatment faults (60% of cases)
Companion codes P0470, P0471, or P0472 may be stored with related pressure circuit issues (40% of cases)
Sensor voltage may read near battery voltage at the connector during backprobe testing (25% of cases)

Likely Causes (Ranked by Probability)

Signal wire short to voltage in the engine harness (45% of cases) — Chafed wiring near the turbo and exhaust routing can contact a power feed, pulling the sensor signal to battery voltage.
Failed exhaust pressure sensor internal short (25% of cases) — A sensor that internally shorts the signal line high produces the same voltage the PCM flags as P0473.
Disconnected or damaged pressure sense tube (15% of cases) — Loss of pressure reference can drive the sensor output to an implausible high value on some 6.7L calibrations.

Step-by-Step Diagnostic Guide

Pull P0473 with Cummins INSITE or Diesel Laptops and note exhaust pressure sensor voltage at idle. Values near 5V or higher with low actual backpressure confirm a high circuit condition. — Tool: scan tool or multimeter. Document readings on the work order.
Inspect the pressure sense tube for disconnection or damage. A disconnected tube can cause erratic or maximum sensor output on some 6.7L configurations. — Tool: scan tool or multimeter. Document readings on the work order.
Disconnect the sensor connector and measure signal voltage at the harness side with key on. Voltage present on the signal wire with the sensor unplugged indicates a short to power in the harness. — Tool: scan tool or multimeter. Document readings on the work order.
Measure sensor signal voltage with the connector attached at idle. Compare to Cummins specification — typically well below reference voltage at low exhaust pressure. — Tool: scan tool or multimeter. Document readings on the work order.
Replace the exhaust pressure sensor if the harness tests clean but the sensor still pulls the signal high. Repair any chafed wiring found near the turbo and exhaust manifold. — Tool: scan tool or multimeter. Document readings on the work order.

Repair Options (with Costs)

Repair	DIY	Independent Shop	Dealer
Exhaust Pressure Sensor wiring repair	$25–$150	$150–$350	$250–$500
Exhaust Pressure Sensor sensor/part	$60 - $280	$$60 - $280 + labor	$300+
Full module replacement	N/A	$600–$1,500	$300+

Platform-Specific Notes

6.7L (2007–2026): Common-rail — Follow cummins OEM diagnostic tree for 0473 on 6.7L.

5.9L (1989–2007): VP44/CP3 — Follow cummins OEM diagnostic tree for 0473 on 5.9L.

When This Code Sets

0473 typically stores after the ECM detects exhaust pressure sensor outside calibrated limits for 1.4–4.0 seconds (OBD-II trip). Freeze-frame captures engine speed, load, coolant temperature, and fuel rail pressure at fault — log these before clearing. Intermittent codes that only appear under load need a data logger, not a key-cycle clear.

Scan Tool Parameters to Log

Exhaust Pressure Sensor live data PID at idle, cruise, and full load
Battery voltage and ECM supply voltage
Related aftertreatment and protection PIDs (SPN 1569 if stacked)

Common Misdiagnoses

Parts-cannon sensor replacement when the harness signal wire is shorted to power — P0473 is read as a bad sensor by default without isolating the circuit.. Instead: Unplug the sensor and measure signal voltage at the harness. High voltage with the sensor removed confirms a wiring repair, not a sensor swap.

Ignoring P0473 because the truck still drives normally — High circuit faults often lack obvious drivability symptoms.. Instead: Repair the circuit promptly. Inaccurate backpressure data affects EGR and DPF regen decisions over time.

Shop Notes from the Field

Shop tip: ProfessionalDieselRepair.com disconnects the exhaust pressure sensor and rechecks signal voltage at the harness on P0473 calls. If voltage stays high with the sensor unplugged, the fault is in the wiring — not the sensor. A parts-cannon sensor swap on a shorted harness wastes time and money.

Safety Warning

Allow exhaust components to cool before disconnecting the pressure sensor or tubes.
Avoid piercing wire insulation when backprobing — use proper piercing probes or T-pins.

Prevention Tips

Inspect harness routing near the turbo for rubbing during scheduled service.
Secure pressure sense tubes to prevent disconnection from vibration.
Address exhaust pressure codes early before soot loading affects related systems.

Ram Cummins Field Notes for 0473

Document ambient temperature and key-cycle count at fault set on Ram Cummins ISX15 — cold-soak faults on exhaust pressure sensor often clear after warm-up when moisture is the root cause.
Compare this unit’s repair history: repeat 0473 within 5,000 miles indicates incomplete prior repair, not a new component failure.
If exhaust pressure sensor was recently replaced, verify correct part number for engine serial — superseded calibrations require matching hardware revision on Ram Cummins.
Capture a 20-minute data log of exhaust pressure sensor parameter during mixed driving before closing the work order — intermittent FMI signatures need road replication, not bay-idle checks.
Check for OEM technical service bulletins covering 0473 on ISX15 — many bulletin fixes address harness routing rather than sensor replacement.
Torque exhaust pressure sensor mounting fasteners per Ram Cummins OEM spec — verify with engine serial. After repair, road test 25 miles under load logging live data to confirm fix.
Document ambient temperature and key-cycle count at fault set on Ram Cummins ISX15 — cold-soak faults on exhaust pressure sensor often clear after warm-up when moisture is the root cause.
Compare this unit’s repair history: repeat 0473 within 5,000 miles indicates incomplete prior repair, not a new component failure.
If exhaust pressure sensor was recently replaced, verify correct part number for engine serial — superseded calibrations require matching hardware revision on Ram Cummins.
Capture a 20-minute data log of exhaust pressure sensor parameter during mixed driving before closing the work order — intermittent FMI signatures need road replication, not bay-idle checks.
Check for OEM technical service bulletins covering 0473 on ISX15 — many bulletin fixes address harness routing rather than sensor replacement.

P0472 — often stacks with 0473
P0470 — often stacks with 0473
P0401 — often stacks with 0473

FAQ

What does P0473 mean on a Ram Cummins?

P0473 means the exhaust pressure sensor signal voltage is higher than the PCM expects. The fault is a high-input circuit condition, not necessarily a physical exhaust restriction.

How do I test for a wiring short on P0473?

Disconnect the sensor and measure voltage on the signal wire at the harness with key on. Voltage near battery or 5V reference with the sensor unplugged indicates a harness short, not a failed sensor.

Can a clogged pressure tube cause P0473?

A disconnected or damaged tube can cause implausible readings on some trucks, but a true high-voltage short is more common. Always verify tube integrity and harness voltage together.

What does 0473 mean on Ram Cummins ISX15?

0473 means exhaust pressure sensor high. The ECM detected exhaust pressure sensor outside calibrated limits. Verify with freeze-frame data before clearing.

Can I drive with 0473 active?

Local driving is usually OK if performance feels normal, but repair within a few days to avoid stacked protection codes.

How much does it cost to fix 0473?

DIY repairs start at $40–$150 for wiring or filters. Shop repairs with parts run $60 - $280. Dealer pricing runs $300+.

What is the most common cause of 0473?

Signal wire short to voltage in the engine harness — confirm with visual inspection and live data before ordering parts.

Sources

OEM service information — Ram Cummins ISX15 diagnostic procedures
SAE J2012 — OBD-II DTC definition for 0473
Mitchell1 ProDemand — 2026 labor and parts cost surveys