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Vehicle Type

Diesel Truck Lemon Law

Powerstroke stuck in limp mode. Cummins DEF countdown to no-start. Duramax regen that never completes. California's lemon law covers new diesel pickups and the emissions systems the EPA forced onto them. If the dealer can't fix it, we can.

Diesel Emissions Systems Break

Modern diesel pickups are saddled with three interlocking emissions systems: exhaust gas recirculation (EGR), diesel particulate filtration (DPF), and selective catalytic reduction (SCR) using diesel exhaust fluid (DEF). Each is complex. Each is failure-prone. And each is engineered to shut your truck down if it detects fault conditions, first by throwing a check-engine light, then by limiting speed, then by blocking the engine from starting altogether.

When a Ford Powerstroke, Ram Cummins, or Chevrolet/GMC Duramax keeps failing the same repair, California's Song-Beverly Consumer Warranty Act entitles you to a buyback, a replacement, or a cash-and-keep settlement, with attorney fees paid by the manufacturer under Civil Code 1794(d).

Typical Diesel Defects We Handle

01

DEF System Failures

NOx sensor failures, DEF pump and injector failures, DEF quality sensor faults, heater element failures, recurring countdowns to no-start.

02

Regen Cycle Issues

Failed regeneration cycles, DPF saturation, manual regen that will not complete, repeated soot loading faults.

03

Limp Mode

Reduced engine power, speed limiter engagement, sudden power loss while towing, intermittent no-start conditions.

04

Turbocharger Failures

Overboost, underboost, variable geometry turbo failures, turbo replacements that fail again within warranty.

05

Fuel System

CP4 fuel pump failures, injector failures, fuel contamination warnings, high-pressure fuel leaks.

06

Transmission

10-speed and Allison transmission shift problems, torque converter shudder, hard shifts, flare shifts under load.

07

EGR Failures

EGR valve failures, EGR cooler leaks, coolant loss into the intake, overheating from EGR-related issues.

08

Dashboard and Wiring

Persistent check-engine lights the dealer cannot clear, body control module faults, CAN bus communication errors.

09

Oil Dilution and Coolant

Fuel-in-oil dilution, coolant crossover into oil, head gasket failures under warranty.

Brand-Specific Issues

Ford Powerstroke (6.7L): DEF pump failures, NOx sensor faults, turbo VGT issues, transmission shift-quality complaints on the 10R140, and intermittent no-start conditions tied to the emissions stack.

Ram Cummins (6.7L): CP4 fuel pump failures on emissions-era Cummins, DEF heater and injector failures, turbo actuator issues, and lift-pump complaints.

Chevrolet/GMC Duramax (6.6L L5P): CP4 pump failures, fuel injector replacements, NOx sensor faults, DEF system failures, and Allison 10-speed shift complaints.

Why "Reasonable Number of Repair Attempts" Gets Reached Fast on a Diesel

Diesel emissions systems are interconnected. A failed NOx sensor can drive DPF regen failures, which can trigger DEF dosing faults, which can cascade to a full limp-mode event. Dealers often swap sensors one at a time over multiple visits. Each visit is a repair attempt. Under Civil Code 1793.22(b), four same-defect attempts within 18 months or 18,000 miles create a statutory presumption in your favor. Most owners of defective diesels pass that threshold quickly. Out-of-service time stacks up too. A cumulative 30 days out of service within that period is a separate statutory trigger.

Your Remedies

Evidence That Matters

Related Lemon Law Resources

Diesel Keeps Failing?

Free consultation. No fee unless we win. Manufacturer pays your attorney fees under Song-Beverly.

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