By Larry Carley. Diagnosis is often the biggest challenge, especially if the cause of a no-cooling problem is not obvious. Is it the refrigeration circuit, an electrical problem or a control issue?

Air-conditioning service stinks sometimes. Let’s face it. I mean it sometimes stinks literally – like bad odor stink. Those of us in the warmer and more humid climates regularly run into customers complaining of a foul odor that emanates from the dash. Your customer today is driving a 2003 Chevy Trailblazer and describes their complaint as this terrible musty odor. When you climb inside the vehicle to confirm the complaint, your nose causes the rest of you to want to do a 180, but you know it’s going to be your job to turn this foul odor into a profitable job. You are all too familiar with the cause and the fix.

According to the new refrigerant’s developers, there are chemical differences between HFO-1234yf and the current R-134a system. As a shop owner, you’ll need to learn the Safety, Equipment and Charging Issues surrounding this new refrigerant.

Gasoline direct injection has been gaining momentum in the industry for some time. BG recently published an article recognizing GDI, and the fact that it will be around for some time. Gasoline direct injection (GDI) was first used in 1925 on the Hesselman engine. Jonas Hesselman designed the engine to start on gasoline and then switch over to run on diesel or kerosene. But in 1952, Bosch developed the first automotive direct injection system that actually ran on gasoline. Mercedes Benz wasn’t far behind in 1955 with the first direct injection sports car, the 300SL.

Airtex offers the following Tech Tip to assist technicians in performing a fuel system voltage drop test. Misdiagnosis is the leading cause of fuel pump problems and returns. Often times a voltage drop test is the only effective way to find excessive resistance in high amperage circuits. It’s a quick and easy test that doesn’t require any dis assembly, and will give you immediate results on whether you’ve got a good connection or a bad one. Check out this tech tip from Airtex offering a step by step procedure to assist technicians in performing this valuable and easy test.

We see it happen all the time. A driver complains about poor gas mileage. No codes are set. Is there a problem that can be fixed? Or, is the driver just hoping for a solution we can’t provide? Extensive testing of the engine, fuel system and ignition system may reveal that fuel injector service, a tune-up, or some engine repair is needed. However, it is much faster and easier and more professional to simply probe the tailpipe exhaust gas and know how to proceed without even raising the hood.

There is a rapidly growing trend for dealerships to suggest that having oil changes done by independent or other non-OEM service providers could compromise warranty coverage. Consumers are listening and increasingly opting to have all routine maintenance performed by OEM dealerships. If you are not concerned about this, you need to wake up and smell the coffee!

As a once-familiar gas jockey greeting passes into history, now-mandatory TPMSs have made it easier for drivers to monitor tire pressures. Servicing these systems is somewhat more complicated than operating a tire pressure gauge.

The problem most automotive technicians face when trying to select an appropriate labscope is reading and understanding labscope specifications and then matching those specifications to the test requirements. Our objective is to explain bandwidth and sampling specs as they apply to automotive testing. Once you’ve read the labscope spec data and compared that data to your requirements you can make a better decision.

“Hybrid vehicle electronics are dangerous and only the dealerships will be able work on them.” “The independent garage is on its way out.” Have you heard statements like these before? I have, and I have to disagree with these opinions, based in part on history.

Powertrain engineers continue to extract more power from and reduce emissions on conventional internal combustion engines. When both intake and exhaust camshafts get involved, GM’s variable valve timing system meets both goals.

By Peter Meier. Fuel flow and injector faults can result in drivability problems. Some OEM scan tools, as well as some high end aftermarket tools, allow you to perform power […]

By Drew Technologies. The days of diagnosing and repairing automobiles without a laptop beside you are quickly fading. Newer vehicles include a large number of onboard computers that are each […]

By Richard McCuistian. Diesel engines all fire their mix using high compression, and they need precisely controlled fuel delivery, both in regard to timing and volume. Diesels typically spin slower […]

I sure hope the average tech prepares very well before he or she starts to work on a hybrid car. A large spark that would sometimes make a tech jump and a co-worker laugh may not seem so funny if the technician is hurt or, worse yet, dead. The safety issues are real. Read this carefully and pass it on to each associate in your shop.

Mode $06 continues to be a hot topic with techs. Nevertheless, there are many techs who have not even heard of Mode $06 or do not even use the Global OBD2 side of the scan data. Knowing how to use Mode $06 could really help in the day-to-day diagnostic problems in your shop.

Back in the days of my youth, a new set of tires that offered a different tire circumference meant a slower or faster speedometer and a trip to the dealership for a new speedometer cable gear to prevent a possible speeding ticket.

If you remember the three critical points of a secondary waveform discussed in our previous article (March 2002), it’s time to continue what we learned and apply it to Distributorless Ignition Systems, (DIS) now known as EI systems.

I think of the Ford/International 6.0L platform as a “bridge” because it spans the gap between the 7.3L with electric-over-hydraulic injectors and the coming 6.4L common rail engine. Common rail injection, made possible by today’s powerful on-board microprocessors, will be the industry standard for a long time to come. The fuel rail pressure, ranging from 5,000 to more than 20,000 psi, is controlled by the electronic control module (ECM). The operation of the injectors is very simple: They still pop, but high fuel pressure on top of the injector piston prevents it until the ECM or fuel injection control module (FICM) sends about 90 volts to operate the injector solenoid, which opens a pressure bleed in the chamber above the piston.

Since the laws of inductively charging the primary circuit and capacitively firing the second circuit have not changed much, I can’t help but wonder why a quick secondary scope check is not part of most modern-day technicians’ diagnostic strategy.

Scan tools are only part of the key to the diagnostic process, knowing when to use them is equally important. If a vehicle comes into your shop with a drivability complaint, should plugging in your scan tool be the first step in diagnosing the problem? Probably not — keep in mind that even though modern engines have sensors and computers that monitor just about every aspect of their operation, deep down they’re still machines that require air, fuel, and oil to run. Remember — a reflash won’t fix everything.

What tools do I need to get into hybrid repair? That is a good question. It all depends on what you have now. What should a technically aware shop have at this time for equipment? A pair of Class O 1000 volt safety gloves with leather protectors, a good digital volt ohm meter (DVOM) rated CAT III @ 1000volts, a lab scope with that same rating, good technical information, and the proper scan tool. There are other hybrid related tools for specific models as well.

This is part two of a Mode $06 series. Last issue covered the intro and terms associated with Mode $06. Now we are going to describe changes to Mode $06 with the advent of CAN communication.

By Ryan Kooiman. How many times have you been scrolling through your scan tool, and somehow run across a screen that said something like:
TID $01 CID$11 Min:$01E1 Max:NA Cur Val:$02DC Result:Pass
This was my first experience with Mode $06.

By Scott Holloway. As a vehicle service and maintenance provider, you are no doubt aware that with the model year 2008 all cars and light trucks sold in the United States have a Direct Tire Pressure Monitoring System (TPMS). These systems actually have been in use for better than ten years and have only recently shown up in the repair centers with a resounding thud! We all know that with change comes opportunity, and TPMS represents huge opportunity for the tire service centers and auto repair garages alike.

By Craig Van Batenburg. In the beginning of hybrid car development the air conditioning systems were R143a systems that shared all the same components as a typical gasoline motor vehicle. The early hybrids were the Honda Insight, Civic Hybrid, Ford Escape, and Classis Prius (2001-2003). All hybrid A/C systems are really climate control. Only the Insight had A/C as an option, and it was a climate control system as well. Every other hybrid to date has factory climate control for some very important reasons.

By Dave Hobbs. Car audio? Been more interested in R.P.M.s than in watts R.M.S.? Better rethink that philosophy with today’s factory car audio and entertainment systems. The technology that used to be a handful of simple circuits like “power, ground, speaker and antenna” and totally independent of other electronic systems has given way to vehicles sprawling with wires and data busses interacting with the audio system.