HINO-P20E8 serious Hino ›

Suction Line Pressure Build Up Check

The HINO-P20E8 (Hino) diesel fault code means: Suction Line Pressure Build Up Check. This is a serious severity code.

My Garage →
Keep driving?
Short distances only
DIY difficulty
intermediate
Mobile mechanic network · I-5 corridor pilot

Down with a Hino fault on the road?

We are building a network of verified mobile diesel and reefer technicians along the freight corridor. It is not live yet — no one can be dispatched to you today. You can see where the pilot is launching and register interest.

View pilot availability →
Built for Diesel — Not a Car Reader
ANCEL HD7000 Heavy-Duty Diesel Scanner

A $30 car code reader can't do diesel. The HD7000 reads full-system codes and does parked DPF regen, idle/speed-limit, and service resets from the cab — on everything from a 6.7 Cummins/Power Stroke/Duramax pickup to Class-8 trucks (Detroit, Paccar, CAT, Volvo, Mack, International).

Check Price on Amazon
FOXWELL HD301 Diesel Truck Scanner
Lower-Cost Diesel Option
FOXWELL HD301 Diesel Truck Scanner

Full-system 6/9/16-pin diesel scan tool for Cummins, Paccar, CAT, Detroit and more — plug-and-play, no subscription. A cheaper way to read heavy-duty codes a basic OBD2 scanner skips entirely.

Check Price on Amazon

Affiliate links — we earn a commission at no extra cost to you.

What Are the Symptoms of HINO-P20E8?

  • Check Engine light
  • DEF dosing stopped

What Causes HINO-P20E8? (Most Likely First)

  • Leaking, kinked or disconnected DEF suction line High
  • DEF pump not building pressure High
  • Empty tank or blocked tank pickup Medium

Can I Still Drive with HINO-P20E8?

Short distances only. HINO-P20E8 is rated serious severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.

Frequently Asked Questions

What does P20E8 mean on a Hino?

P20E8 means Suction Line Pressure Build Up Check. Abnormal pressure in the DEF pipe: with SCR inlet exhaust temperature above 150 °C and DEF defrosting complete, the line pressure fails to rise above 8,000 hPa (116 psi) within 50 seconds of the pump starting, three times in a row.

Is P20E8 a Hino-specific code?

P20E8 is an SAE-format powertrain code, but the title and the conditions here are Hino's own, read from Hino's service documentation, not a generic definition.

Mechanics Guide Step-by-step diagnosis

How Do You Diagnose HINO-P20E8?

  1. Inspect the DEF pipes and run the DEF pipe leak test with the diagnostic tool.

  2. Check DEF pressure at the hose, the tank sensor and the pump in turn.

Sources 2

This page is built from documented references. Verify against your own service info before repair work.

  • Hino Workshop Manual, HINO 238 / 258LP / 268 / 338 series with J08E-VB and J08E-VC engines, DEF SCR System (DCU) chapter, DTC P20E8 "Suction Line Pressure Build Up Check"technical description and detection conditions. Distributed through Hino's dealer service portal; no public link.
  • SAE J2012Diagnostic Trouble Code Definitions (defines P20E8 as a generic OBD-II code)

P20E8 on Other Platforms

The same code ID appears across other engines, vehicles, and equipment. Diagnostic flow varies by platform — see the matching breakdown:

Bobcat serious Reductant Pressure Too Low Isuzu serious Reductant Pressure Too Low Kubota serious Reductant Pressure Too Low PACCAR serious PACCAR MX fault code P20E8 — definition not reliably documented Yanmar serious Reductant Pressure Too Low

Explore More

More Hino codes → Diesel home All diesel codes Heavy-duty Guides

Was this helpful?

Send this to whoever is fixing the truck — your tech, or the person asking what the fault means.