Chevy Silverado and GMC Sierra HD trucks with the Duramax diesel are built to tow — and they need a shop that knows the fuel system, turbo, emissions and Allison transmission inside out. C.C. Automotive has worked on Tucson diesels since 1981.
Whether it's an early LB7 with injector problems, an LML with a CP4 fuel pump you're worried about, or a late-model L5P throwing DEF and regen codes, we have the scan tools, rail-pressure and injector balance testing to find the real problem — not throw parts at it. Hard starts, smoke, low power, reduced-power mode, turbo and cooling issues: we see Silverado 2500HD, 3500HD and Sierra HD trucks from Tucson, Marana and Sahuarita every week.
We also take care of the truck around the engine — Allison transmission service, heavy-duty brakes, front-end and steering, and lift kits with the alignment to match. Every repair is backed in writing by our 12-month / 12,000-mile warranty, with a free shuttle and financing available.
CP3/CP4 pump testing, injector balance rates, lift pump and fuel filter service — the most expensive part of a Duramax to get wrong.
VGT turbo vane and actuator faults, boost leaks, intake and charge-air cooler testing for low power and smoke.
Regen problems, DEF quality and NOx sensor faults, EGR valve and cooler — diagnosed properly and repaired to keep the truck legal.
Allison 1000 and 10-speed service, transfer case, heavy-duty brakes, front-end parts and lift kits with alignment.
Often a weak lift pump, air in the fuel, a failing glow plug system or injector return flow out of spec.
Rail-pressure faults, turbo vane sticking, a boost leak or an emissions derate — each needs a different fix.
Each color points somewhere different — injectors, oil or air — so we test rather than guess.
A warning sign of CP4 pump failure on the LML. Catching it early can save the injectors and rails.
Frequent regens, DEF quality codes or a speed-limit countdown need attention before the truck limps you home.
Radiator, fan clutch, EGR cooler or a clogged charge-air cooler under Tucson summer heat.
Early common-rail. Known for injector wear and fuel leaks — we test balance rates before replacing.
First Duramax with a VGT turbo. Runs hot when towing — we check the cooling system and turbo carefully.
Strong engine with no DPF. We keep the fuel system, turbo and Allison healthy for the long haul.
First with a DPF. Regen and EGR issues are common — diagnosed with the right scan tools.
DEF/SCR system and the CP4.2 fuel pump. We watch for metal in the fuel before it spreads.
Most powerful Duramax. DEF, NOx sensor and regen faults — plus the 10-speed Allison on newer trucks.
Also the 3.0L Duramax inline-six in the Silverado 1500 and Sierra 1500. Not sure which engine you have? It's on the sticker under the hood, or just call and we'll tell you from the VIN.
Our crew tells you straight what your car needs — never an upsell, never a runaround. Just quality parts and repairs done right.
We stand behind every repair — in writing.
Drop your car off — we'll get you to work or home and back.
Domestics, trucks and imports — Chevy, Ford, Dodge, Toyota, Honda, Nissan, Lexus and more.
A Tucson family shop that treats your vehicle like our own.
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Lease-to-own and flexible plans — a fast path to yes on bigger repairs.
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They tell you straight what your car needs — no upselling, no runaround, just honest answers.
30 years in the auto business and this shop finally earned my trust — top quality in every respect.
Same-day diagnosis and repair, honest pricing — I'd give 100 stars if I could.
We scan and inspect with the latest tech to find the real problem — fast, no guesswork.
We tell you exactly what your car needs and what it costs — before we touch a wrench.
Quality parts, careful work, and a 12-mo / 12K-mi warranty in writing. Free shuttle included.
Fastest way to book is a call. Online requests may take up to 24 hours.
Thanks — we'll be in touch soon. Need it faster? Call (520) 624-9250.
All of them — the 6.6L LB7, LLY, LBZ, LMM, LML and L5P in the Silverado and Sierra 2500HD/3500HD, plus the 3.0L Duramax inline-six in the half-ton trucks.
Yes. We test rail pressure and check the fuel for metal before anything is replaced, and we explain the options if the pump is on its way out.
Yes. We can command forced regens, test NOx and DEF quality sensors and diagnose the DPF and SCR system properly — no dealer trip needed.
Yes — fluid and filter service, diagnostics and repair on the Allison 1000 and the newer 10-speed Allison behind the L5P.
Usually yes at low speed, but if it's overheating or a DEF countdown is near zero, call us first at (520) 624-9250. We're right off N Stone Ave near I-10.
Every repair at C.C. Automotive is backed by a written 12-month / 12,000-mile warranty.
