Cummins fault code 2273

What it means

Cummins' description: Exhaust Gas Recirculation Differential Pressure Sensor Circuit - Voltage above normal, or shorted to high source.

SPN 411 is Engine Exhaust Gas Recirculation 1 Differential Pressure. FMI 3 means the voltage on the circuit is higher than possible for a good sensor, usually an open signal wire, a short to a power wire, or a failed sensor.

The EGR system routes a measured amount of cooled exhaust back into the intake to lower combustion temperature and NOx. It uses a valve, a cooler, temperature sensors and a differential pressure sensor to measure flow.

What the lamp means

An amber (yellow) warning lamp means the engine can usually keep running, but the fault should be repaired soon, ideally the same day.

Common causes

FMI 3 is an electrical or signal fault, so start with the circuit:

• EGR valve position sensor or actuator wiring fault
• Failed EGR temperature or differential pressure sensor
• Cracked sensor hose on the differential pressure sensor

If the circuit checks out, the reading may be real. Other possibilities: eGR valve sticking from soot buildup; clogged EGR cooler restricting flow; leaking EGR cooler (watch for coolant loss or white smoke).

What you can check before calling

• Check coolant level. Unexplained loss can point to an EGR cooler leak
• Look for white smoke or a sweet coolant smell from the exhaust
• Look for soot tracks or loose hoses around the EGR valve and pressure sensor

Clearing the code without fixing the cause usually brings it right back, and on emissions systems it can restart derate timers.

Engines and sources

Listed by Cummins for: QSB 6.7, QSL 9, QSX 15, QSB 4.5, QSF 3.8. Cummins uses the same fault code numbers across its electronic engines, including on-highway models like the ISB/B6.7, ISL/L9 and ISX/X15, though not every code applies to every engine or software level. Source: Cummins Tier 4 Fault Codes. Always confirm with Cummins service information (QuickServe) for your engine serial number.