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 October 15, 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
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
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
Verify freeze-frame conditions and repeat the fault under load.
Inspect fuel tank pickup/strainer and replace fuel filter per service interval.
Check for external leaks and air ingress on low-pressure lines and at the in-tank module seals.
Monitor low-side fuel pressure with a scan tool while commanding pump operation; compare to expected supply pressure.
If pressure remains low with a known-good filter and no leaks, evaluate the in-tank electric supply pump/module performance.
Do not perform step-by-step repair of high-pressure fuel lines; diagnosis only.
Parts and tools you may need
Scan tool with live data for low-side fuel pressure
OBD-II scan tool — Read P008A freeze-frame and monitor live low-side fuel pressure while commanding the in-tank pump under load.
Fuel pressure gauge — Directly measure supply-side pressure at the filter head to confirm low pressure versus scan-tool data.
Digital multimeter — Check in-tank pump/module supply voltage and current draw to identify electrical degradation.
Borescope — Inspect tank pickup/strainer and module seals for restriction or debris without dropping the tank.
Rough cost and difficulty
Likely repair
Parts
Shop labor
Who usually does it
Fuel filter service
$30–$150
0.3–1 hrs
Easy DIY
Fuel supply or return line repair
$30–$200
0.5–2 hrs
DIY with tools and a manual
Lift pump / fuel transfer pump
$100–$400
1–3 hrs
DIY with tools and a manual
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 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.
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.
