What Scanner Do I Need For A Duramax? GM mechanic says… – Rustyautos.com (2022)

Working on a Duramax is not for the faint-hearted, but you already know that. I’m a GM-trained technician, and I’ve worked on a ton of Duramax trucks. Most days, I love them, but some days…. aghhh …they make me so grumpy.

The best scanner for a Duramax is the Autel MaxiCOM Mk808. The MaxiCOM performs simple tasks such as reading and clearing fault codes, resetting service intervals, codes injectors, keys, performs relearn procedures for transmission, throttle, steering angle sensors, codes new batteries, performs DPF regens.

In this post, you’ll learn why I like the Autel MaxiCOM for the Duramax. You’ll also learn some of the common issues I met as a Duramax mechanic working at the dealership.

What You Need From A Scanner

Duramax is a no-nonsense get her done kind of engine, and in my experience, the owners tend to be of a similar build – hard-working, DIY, salt of the earth, no BS, get her done types.

Tools that are up to the job are important. At the dealership, I used the bulletproof GM Tech2 handheld scanners for the older trucks. The newer vehicles used the wireless MDI system.

The old GM Tech 2 scanners were tough, no doubt about it. I witnessed an apprentice test drive a truck with a Tech 2 trailing from the door jam. Nice!

But the problem with the old Tech 2 is they were clunky and slow to use, the new system is great, but it’s a laptop/desktop-based system with a wireless interface and spendy to buy.

The tool I recommend for your Duramax is the Autel MaxiCOM MK808, it’s competent, does almost everything a DIYer needs to do, it’s robust, and is easy to use.

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If you simply want to read powertrain fault codes, that’s fine. Autel has a less expensive reader for that too.

But, if you need to go delve deeper and run more sophisticated tests and adaptions, you’ll need a bidirectional scanner.

You can check out all scanners here on the Mechanics tools page.

Why I recommend the Autel

The Autel MaxiCOM has a good range of functionality without costing a ton. I’ve used their tools for years and trust them.

That said the MaxiCOM won’t solve all your Duramax problems. If you are dealing with a more complex problem you’ll need a bidirectional scanner. Bidirectional tools are pro tools and you already know these guys are typically not cheap.

The extra functionality of the pro-type bidirectional tool allows you to operate components from the scan tool, capture live data, and adapt components after fitting.

For most DIYers the Autel MaxiCOM is great.

  • Strong and reliable – I’ve been using Autel products for years and have yet to break one
  • Easy to use – Hook up and finds your vehicle automatically, color touch screen with big clear buttons
  • Range of functions – It reads codes and live data on all systems not just the powertrain. Resets service intervals, codes injectors, keys, performs relearn procedures for transmission, throttle etc. steering angle sensors, codes new batteries, performs DPF regeneration and a ton of other good stuff.
  • Range of vehicles – Works on nearly all vehicles, new and old and that’s important. It means you can work on multiple family vehicles without buying another scanner.

Common Duramax Problems

The Duramax engine is a serious tough unit, but it does have some weaknesses, and like all motors, it needs love from time to time. In our dealer workshop, the harder working Duramax engines were actually less trouble.

The most problematic Duramax tended to be the barely worked school-run truck. This content is owned by moc.sotuaytsur. They would typically come in with blocked EGR cooler issues or DPF and SCR sensor issues.

Your Duramax is a great engine, well designed, tested, and fit for purpose. But use caution if tuning the motor. I’ve worked on a few coal burners, and it hasn’t ended well. I’ve stripped motors with cracked pistons and broken cranks. These are expensive failures that could have been avoided.

Here are some common Duramax problems I would regularly see. Some issues are very common, and as a Duramax owner, you may already be familiar with one or two of them.

The most common failures include:

  • Injector failure
  • Fueling issues
  • Head gasket failure
  • Water pump failure
  • Egr cooler failure
  • Fuel pump failure
  • SCR system faults
  • Manifold faults
  • Engine harness failure

The Autel MaxiCOM will be invaluable when diagnosing and repairing these types of Duramax issues. However, for some, you may need a bidirectional scanner. You can check out the MaxiCOM along with a ton of other tools here on the Mechanics tools page.

Fuel Injector Failure

Fuel injector leaks internal and external. That’s not unusual. Having the tools to diagnose the root cause of the fault is crucial to nailing the repair the first time out. Incorrectly calling failed parts on these trucks can be expensive. A single injector alone can cost $400 plus.

But not finding a leaking issue can be even more expensive. A leaking injector will dilute the engine oil and possibly cause a catastrophic engine failure.

Running an injector balance rate test is easy with the Autel. The balance rate is a measurement of fuel delivery across all injectors. A significant difference between the cylinders means you likely have an injector issue.

Injector issues are common across the LB7 and LBZ engines.

Fueling Issues

Duramax employs a lift pump, also known as a low-pressure pump, to move diesel from the fuel tank to the high-pressure pump. The fuel filter housing seal lets go and allows air to sneak in, this commonly contributes to fuel starvation.

Water pump failure

Water pump leaks are common, too, across all the engines. Replacing a water pump is a maintenance issue with all engines. But with these big V8s, we need to be careful of overheating the motor, especially when towing.

Faultyfans and dirty, clogged-up radiators are common causes of overheating too.

Head Gaskets Faults

Blown head gaskets are especially common in tuned engines. The gasket commonly fails across the back of the motor at the firewall, where exhaust heat increases gasket stress.

EGR cooler failure

EGR cooler leaks are a motor killer. The EGR cooler can fail to allow coolant to enter the intake and the motor, which doesn’t end well. Keep a sharp eye on coolant levels, investigate coolant loss immediately.

SCR system faults

The SCR (Selective Catalytic Reduction) system is designed to make our world cleaner…well, it certainly made GM technicians a touch grumpier. The system was fraught with issues from NOx sensor failure to DEF fluid freezing, DEF pump, and fluid level sensor failure.

The Autel MaxiCOM, unfortunately, does not command test SCR heater circuits.

Fuel pump failure

High-pressure fuel pump failure is uncommon with the exception of one pump. The Cp4 Bosch pump fitted to LML engines. It’s particularly prone to granding, lack of lube, usually poor quality diesel.

Replacing the pump may not be the end of the expense, metal filings from the pump are distributed throughout the fuel system – rail, injectors and it can cost a packet to put right.

Engine harness failure

The V8 vibration has a knack of chafing the wiring harness loose and eventually rubbing a wire and shorting to chassis ground. Engine bay real estate is tight in a Duramax. Harness rubbing is not unusual as no matter which path a loom takes, it’s never far from a chafing hazard.

Motors that have had significant work seem to be more prone to chafing as looms may not be secured or routed correctly.

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What scan tool does GM use? ›

GM Tech 2: This is the GM factory scan tool used in all GM dealers since 1996. Model coverage includes all makes and models of GM vehicles including passenger cars, trucks and vans.

How do I connect my scan tool to my engine? ›

In powering this one up you just press the button like this this one is externally powered not all

What is a GM Tech 2 scan tool? ›

The Tech 2 is a powerful, versatile hand-held diagnostic computer, designed to help diagnose and repair today's automotive electronic systems. The Tech 2 supports the changes in the on-board electronic systems for model years 1996 and beyond.

Does GM still use Tech 2? ›

Tech 2 has been replaced by a newer one and it's GM only. No worth spending money on a tool that is now obsolete and can't be upgraded to work on a car you may get next year.

How do I check my engine codes without a code reader Chevy? ›

A. Using The Ignition Key
  1. Step 1: Turn The Ignition Key. Switch ON and OFF the ignition key without running the engine. ...
  2. Step 2: Check Your Dashboard. Right after the dash lights come up, they'll turn off, except one—usually the service engine light. ...
  3. Step 3: Note And Interpret The Check Engine Codes.
27 Oct 2021

Can you damage your car using an OBD2 scanner? ›

It's completely safe to leave an OBD2 scanner tool plugged in while driving. In fact, it's important to have your car running while you diagnose an engine code to avoid damaging the scanning software.

How do I choose an OBD2 scanner? ›

Characteristics of an ideal OBD-II scanner
  1. The delay in producing the reading should be as small as possible i.e. the diagnostic system should produce a result with great accuracy instantaneously.
  2. The compatibility should be there for any model or make. ...
  3. The system should be user friendly and easy to understand.
17 Jul 2019

What is GM MDI used for? ›

The GM MDI 2 is the Global Diagnostic Interface tool for both current and future GM vehicles. It replaces the MDI introduced in 2007 and offers a compact communication module with increased processing power and security to offer faster transfer of data between a vehicle's onboard ECU network with an auxiliary CAN bus.

What can you do with a Tech2 scanner? ›

The Tech2 is a scanning device which is able to let you deep dive into the internals of the various systems in your vehicle. While generic scanners can show and decode error codes, the Tech2 has the ability to get into the details of the error. Also the Tech2 is able to set brand/type specific settings.

When did Tech 2 come out? ›

id Tech 2. Originally known as "Quake engine", it was originally written to power 1996's Quake. It featured true 3D real-time rendering and is the first id Tech engine to use the client–server model. The source code was released on the 21st of December 1999 under GPL-2.0-or-later.

What scan tool does AutoZone use? ›

Code Reader - OBD2 Scanner & Car Diagnostic Tool | AutoZone Scanning Tools.

What is GM GDS2? ›

The GM Global Diagnostic System 2 (GDS2), a PC-based software application, is designed to diagnose and repair on-board automotive electronic systems. The software application is used with a personal computer and a GM MDI (or J2534-2 equivalent).

What is global B GM? ›

The advanced “digital vehicle platform,” known internally as Global B debuted with the 2020 Cadillac CT5 sedan. It serves as the electrical foundation for the 2020 Chevrolet Corvette Stingray and the 2021 Chevrolet Tahoe and Suburban, GM Yukon and Cadillac Escalade.

What is GM MDI? ›

The GM MDI 2 is the Global Diagnostic Interface tool for both current and future GM vehicles. It replaces the MDI introduced in 2007 and offers a compact communication module with increased processing power and security to offer faster transfer of data between a vehicle's onboard ECU network with an auxiliary CAN bus.

What cars does Tech 2 work with? ›

  • This Vetronix Tech II Diagnostic Scanner is designed to work with the cars of different brands such as GM, Saab, Opel, Isuzu, Suzuki, and Holden. ...
  • If you want to perform the trucks diagnostic with this tool, you will need to obtain the Truck Adapter, which is not included in this set.

How do I download Tech2Win? ›

Installing the Tech2Win Driver.

Open your internet browser and type in the address bar www.drewtech.com. Once on the home page, scroll to the bottom and click the “Download Link” Page 2 2. Scroll to “Support Applications” and click the DrewTech_Tech2Win Driver link. And choose “Run” Page 3 3.

Is there a OBD1 scanner? ›

Innova 3123 OBD1 scanner is an ideal code reader for the US-GM cars and trucks manufactured from 1982 to 1996. It is a friendly and modern device to find out the problems in the vehicles. It is an affordable device for the common people. Anyone can use it after reading the some instructions on the manual book.

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