Diesel Trouble Codes

P008A — Low Pressure Fuel System Pressure Too Low (6.7 Cummins (EGR + DPF, pre-SCR))

Diagnostic reference for 6.7 Cummins 2007.5–2012 EGR+DPF pre-SCR with code P008A.

Updated September 2, 2026

What it means

Low-side (supply) fuel pressure is below expected on this platform. The code is defined as Low Pressure Fuel System Pressure Too Low and the affected systems are fuel supply and lift pump.1

Most likely causes

  1. In-tank electric supply pump / fuel module degraded or failing — Factory low-pressure supply is an in-tank electric pump/module. Low supply pressure is the generic definition for P008A.1
  2. Restricted fuel supply (tank pickup, strainer, lines, filters) causing low supply pressure — Supply restriction reduces low-side pressure; P008A is low-side pressure too low.1
  3. Air ingress on the low-pressure side (leaks at connections, fittings, or module seals) — Air in the supply reduces effective pressure; code indicates low-side pressure below expected.1

How to diagnose

  1. Verify freeze-frame conditions and repeat the fault under load.
  2. Inspect fuel tank pickup/strainer and replace fuel filter per service interval.
  3. Check for external leaks and air ingress on low-pressure lines and at the in-tank module seals.
  4. Monitor low-side fuel pressure with a scan tool while commanding pump operation; compare to expected supply pressure.
  5. If pressure remains low with a known-good filter and no leaks, evaluate the in-tank electric supply pump/module performance.
  6. Do not perform step-by-step repair of high-pressure fuel lines; diagnosis only.

Parts and tools you may need

Rough cost and difficulty

Parts and labor vary by region and vehicle condition.

When to see a pro

If low-side pressure cannot be restored after filter and leak checks, or if high-pressure fuel system symptoms appear, have a qualified diesel technician evaluate the in-tank supply pump/module and fuel system integrity. Do not service high-pressure fuel components without proper training and safety equipment.

Sources

  1. 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.

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