P042E — Exhaust Gas Recirculation Control Stuck Open — 6.7 Cummins (SCR / DEF)
Exhaust Gas Recirculation Control Stuck Open
What it means
The EGR control circuit reports the valve stuck in the open position on the 6.7L Cummins SCR/DEF 2013–present. This platform has an EGR valve + cooler, DOC/DPF/SCR+DEF, VGT HE300VG with electric actuator+position sensor, CP3 2013-2018 & 2021+, CP4.2 2019-2020 only, in-tank lift pump, rail pressure sensor, FCA/MPROP, mechanical rail pressure relief valve, solenoid common-rail injectors, grid heater, no glow plugs, mechanical wax thermostat, gear-driven timing, MAP primary with MAF for EGR/emissions.1
Most likely causes
- EGR valve stuck open mechanically due to carbon buildup / soot fouling in valve and cooler passages — Carbon accumulation can hold the valve off its seat, keeping EGR flow higher than commanded. Typical on 6.7L Cummins 2013–present with EGR valve+cooler present.1
- EGR valve position sensor / actuator feedback error causing the ECM to infer stuck open — The ECM monitors commanded vs. actual EGR position. A faulty position sensor or wiring can make the control circuit appear stuck open even if the valve moves. Platform uses EGR valve+cooler and MAP primary with MAF for EGR/emissions.1
- EGR control circuit electrical fault — wiring, connector corrosion, or ECM driver issue — Open/short in the EGR valve control wiring or poor connector contact can set a stuck-open diagnostic. Affected systems: EGR on 6.7 Cummins SCR/DEF.1
- Excessive EGR flow due to intake/EGR restriction or cooler internal failure affecting flow measurement — Restriction or internal cooler breach can alter measured EGR flow relative to command, contributing to P0402-type excessive flow conditions on this platform.2
How to diagnose
- Verify freeze frame and confirm P042E is active on 6.7L Cummins SCR/DEF 2013–present with EGR hardware present.
- Inspect EGR valve and cooler for carbon/soot fouling and mechanical binding; check valve pintle movement and seat condition.
- Check EGR valve position sensor signal and actuator command vs. actual with scan tool; compare to MAP/MAF-based EGR flow expectations.
- Inspect EGR control wiring and connectors for corrosion, chafing, or poor pin contact; perform pin drag and continuity tests per service info.
- Review related EGR flow codes such as P0401 insufficient flow and P0402 excessive flow for pattern clues on this platform.
Common mistake to avoid
Replacing the EGR valve without testing it. If the valve still moves freely, a carbon cleaning often fixes the flow code; and if it opens on command but the code stays, the blockage is in the passages or cooler, not the valve. Source: FleetRabbit — EGR valve problems and repair.
Parts and tools you may need
- Scan tool with Cummins enhanced diagnostics
- Digital multimeter
- EGR valve position sensor test harness
- Borescope for intake/EGR inspection
- Carbon cleaning solvent and soft brushes
- Torque wrench
Tools you’ll need
- OBD-II scan tool — Reads P042E freeze frame and live EGR valve commanded vs. actual position plus MAP/MAF data to confirm stuck-open inference on 6.7L Cummins.
- digital multimeter — Checks EGR valve position sensor supply, signal, and actuator command voltages and wiring continuity for circuit faults causing stuck-open detection.
- borescope — Inspects EGR valve pintle, seat, and cooler passages for carbon/soot fouling and mechanical binding without full disassembly.
- fuel pressure gauge — Rules out rail pressure anomalies that can affect combustion and EGR flow calculations during diagnosis of P042E.
Rough cost and difficulty
| Likely repair | Parts | Shop labor | Who usually does it |
|---|---|---|---|
| EGR valve/passage carbon cleaning | $20–$100 | 1–4 hrs | DIY with tools and a manual |
| Wiring or connector repair | $10–$100 | 1–4 hrs | DIY with tools and a manual |
| EGR position/temperature/differential pressure sensor | $60–$300 | 0.5–1.5 hrs | DIY with tools and a manual |
| EGR cooler | $400–$1,200 | 4–8 hrs | Shop |
Typical US independent-shop figures; labor runs about $120–$180 per hour (dealers charge more). Confirm the diagnosis before buying parts.
When to see a pro
If the EGR valve is seized, the intake/EGR passages are heavily carboned, or wiring/ECM driver faults are suspected, have a qualified diesel technician perform inspection and repair. Do not attempt high-pressure fuel or turbo work without proper training.
Check for recalls
Recalls are tied to your truck’s VIN, so check yours directly: enter the VIN at NHTSA’s recall lookup. Open safety recalls are repaired free at a dealer.
Sources
Repair videos: P042E on the 6.7 Cummins '13+
Third-party videos, not ours — picked for this engine. Confirm anything against the factory service information for your truck.
Spotted an error, or something missing? Tell us
Run a 6.7 Cummins (SCR / DEF)? This goes straight to the editor — it is not published.