Why does my diesel truck's DEF consumption suddenly increase?
A sudden spike in DEF consumption usually means the SCR system is dosing more fluid to compensate for inefficient NOx conversion, often…
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Heavy-Duty Vehicles & Fleet
Practical, step-by-step fixes for heavy-duty vehicles & fleet problems — 67 published so far.
Why does my diesel truck's DEF system keep throwing a P20EE code?
A P20EE code means your diesel truck's DEF system isn't converting NOx properly, usually because the DEF fluid is contaminated, the injector…
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Why does my diesel truck's DEF system keep throwing codes after refill?
Contaminated or stale diesel exhaust fluid (DEF) is the most common cause of recurring DEF system codes after a refill — even…
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Why does my diesel truck's DEF system keep throwing codes and going into derate?
A DEF system derate usually means the aftertreatment can't meet emissions targets — most often from a clogged DEF injector, bad NOx…
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Why does my diesel truck's DEF system keep throwing codes and going into limp mode?
A DEF system throwing codes and forcing limp mode usually means contaminated diesel exhaust fluid, a failed NOx sensor, or a clogged…
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Why does my diesel truck's DEF system keep throwing codes?
DEF system codes usually mean contaminated fluid, a clogged injector, a failed NOx sensor, or a faulty dosing valve — not a…
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Why does my diesel truck's DPF filter clog so quickly on short urban routes?
Short trips prevent the diesel particulate filter from reaching the 600°C needed for passive regeneration, so soot accumulates until the ECU forces…
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Why does my electric delivery van lose 30% range in cold weather and how do I fix it?
Cold temperatures slow battery chemistry and increase heating loads, cutting usable range by 20-40%; pre-condition the cabin while plugged in, use seat…
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Why does my electric delivery van lose 30% range in cold weather?
Cold temperatures slow the chemical reactions inside lithium-ion batteries, reducing usable capacity by 20-40% and increasing energy needed for cabin heating. Preconditioning…
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Why does my electric delivery van lose 30% range in winter?
Cold temperatures reduce battery chemical activity and increase heating demand, cutting an electric delivery van’s range by 20‑30%. Preconditioning the cabin while…
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Why does my electric delivery van's range drop 30% in winter and how do I fix it?
Cold temperatures reduce battery chemistry efficiency and increase heating demand, cutting EV range by 20-40%. Precondition the van while plugged in, use…
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Why does my heavy-duty diesel truck keep going into limp mode after a DPF regeneration?
Your truck enters limp mode after DPF regeneration because the soot load didn't drop enough, often due to a clogged filter, failed…
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