Diesel Trouble Codes

P042E — Exhaust Gas Recirculation Control Stuck Open (6.7 Cummins (EGR + DPF, pre-SCR))

Diagnostic reference for 6.7L Cummins 2007.5–2012 (EGR + DPF, pre-SCR).

Updated September 2, 2026

What it means

The EGR control circuit reports the valve stuck in the open position.1

Most likely causes

  1. EGR valve stuck mechanically open due to carbon/soot buildup in valve or cooler passages — Valve fails to close; EGR flow remains high when commanded closed.12
  2. EGR valve position sensor / feedback circuit fault causing ECM to interpret valve as open — Erroneous position feedback makes ECM think valve is stuck open.13
  3. EGR control circuit wiring or connector issue affecting valve command/feedback — Open/short or corrosion in EGR valve harness leads to stuck-open detection.13
  4. EGR valve actuator/electrical driver fault — Valve actuator cannot close properly due to electrical fault.13

How to diagnose

  1. Verify code and freeze frame; confirm P042E is present on 6.7 Cummins 2007.5–2012 EGR+DPF pre-SCR platform.
  2. Inspect EGR valve and cooler for carbon/soot buildup that can mechanically hold valve open. [1,4]
  3. Check EGR valve position sensor feedback and related wiring/connector for opens, shorts, or corrosion. [1,2]
  4. Command EGR valve through scan tool and monitor commanded vs actual position; look for failure to close. [1,2]
  5. Inspect EGR control circuit integrity and actuator operation; verify electrical supply and ground to valve. [1,2]

Parts and tools you may need

Rough cost and difficulty

Parts and labor vary by region and vehicle condition. Obtain local quotes.

When to see a pro

If diagnosis is inconclusive or repair involves high-pressure fuel or emissions-critical components, have a qualified diesel technician perform diagnosis and repair.

Sources

  1. Curated DTC seed — 6.7 Cummins (EGR + DPF, pre-SCR) (curated) ↩︎ ↩︎ ↩︎ ↩︎ ↩︎

  2. Curated DTC seed — 6.7 Cummins (EGR + DPF, pre-SCR) (curated) ↩︎

  3. Curated DTC seed — 6.7 Cummins (EGR + DPF, pre-SCR) (curated) ↩︎ ↩︎ ↩︎

Watch a repair

Third-party videos, not ours — for illustration. Confirm anything against the factory service information for your truck.

WATCH How EASY This Ford 6.7L Diesel EGR Repair Is! — ProMaxx Tool · 84K views

Avoided Disaster Ford 6.7 Power Stroke Egr Valve Replacement — Drews Shop Life · 62K views

2019 6.7 Powerstroke EGR Maintenance: The Problem With Carbon Build-Up — Dave's Auto Center · 170K views