With some of today’s cars diagnosing those supposedly ‘simple functions’ such as power door locks, power seats, or power windows can get overly complicated. For example, I took a call recently on a 2001 Mercedes C-class. The driver’s complaint was that the door locks wouldn’t work after the car sat for more than an hour, but once they started to work again, they would be fine as long as you used them.

Tags: Diagnostic equipment, Service bays, Technicians, Underhood service

Since the start of OBD-II diagnostics, Toyota has used different ways of testing the evaporative emissions system for leaks. The most recent system, starting with 2005 model year, is used on many Toyota, Lexus and Scion vehicles. This system tests for leaks using an evaporative leak detection pump module that is mounted on the charcoal canister under the vehicle. The leak detection pump module reduces the total number of parts.

Tags: Engine Diagnostics, Service bays, Technicians, Underhood service

Air conditioning service and repair can be profitable, with few comebacks, or it can be your worst nightmare. Most technicians know that when a customer walks in and wants a tune-up, it’s time to ask a lot of questions. Customers assume their driveability issue will be solved by the magic of this service. It may be, but don’t count on it. The same issue occurs when they ask for “a shot” of refrigerant to fix their air conditioning.

Tags: Air conditioning, Service bays, Technicians, Underhood service

Do you remember taking your test for your driver’s license? I’ll bet you chose a car and left your truck at home. Good choice. Trucks do a lot of things well, but maneuvering easily has not always been one of them. In 2003, however, General Motors added 4-wheel steering as an option on several of its trucks. This “Quadrasteer” system dramatically reduces turning radius and improves overall handling. Here is what you need to know about it.

Tags: Service bays, Steering, Technicians, Under-car service, Underhood service

From an engineering standpoint, most technicians can see the logic behind module-to-module communication. In theory, it makes sense to have a single input such as a vehicle speed sensor feed just one module, and then have that module share the information over a pair of data bus wires to other modules. Unfortunately for the technicians faced with the challenge of diagnosing and repairing these problems, module-to-module communication often makes our job significantly more difficult.

Tags: Brakes, Service bays, Technicians, Underhood service

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In the late 1990’s, Honda automobiles started using a blower motor power transistor to control the speeds of the blower motor instead of the traditional blower motor resistor. Now, when the blower motor power transistor fails, the air conditioning (A/C) compressor will become inoperable. When the blower motor does not operate on later model A/C systems, the heater control panel will set a code which in turn shuts off the request for A/C compressor operation.

Tags: Air conditioning, Service bays, Technicians, Underhood service

While I was working for a Saturn dealer, a new 2006 Saturn Ion was delivered from the factory with a problem in the electrical system. When the vehicle sat for more than a day or two, the battery would be dead. I checked for any lights or modules that were operating with the key off, and noted that the radio clock display was lit -- though there was no sound from the radio-when the key was not in the ignition. Turning on the ignition switch caused the radio to function normally.

Tags: Electrical Service, Saturn Ion, Service bays, Underhood service