Diagnostic Dilemmas: The Effects of Warm-Up Laps on a Running Engine
Most diagnostic technicians have experienced the frustrations of troubleshooting temperature-related engine performance problems. All too often, the true nature of the problem is concealed by the very fact that it occurs only at specific engine temperatures. If the engine quickly passes through the critical temperature range needed to duplicate the problem, the problem can easily
Checking into Mode $06
Mode 06 is the actual system test data that OBD II looks at when it decides to set a pending code or a current fault code. If the test data is within the limits established by the vehicle manufacturer, the item gets a PASS and no codes are set. But if a value is out of range, OBD II flags it with a FAIL and keeps an eye on the component until the system monitor has run at least twice. Then, if the problem is still there, a DTC is set and the MIL light comes on.
Selling Service for Low-Maintenance Ignition Systems
ition system maintenance as long as it feels like it’s “running good.” In reality, spark plugs eventually develop high electrical resistance because the electrodes wear away. When this happens, the secondary ignition voltage will increase until the ignition coil, ignition cable, spark plug boot or spark plug develops a high-voltage leak. When a high-voltage leak
Flash! Reprogramming Vehicle Computers
Typically, when someone brings up the subject of “flashing” you get two reactions. The technologically informed service professionals think about added revenue and service, while rowdier folks think about doing something that could land them in front of a judge. I think we can all agree that the first group is far better off, and
Selling Oxygen Sensors
As modern OBD II technology marches on, it’s clear that the zirconia-based oxygen sensor now is being sold more as a basic repair part than as a preventive maintenance part, and it changes the way we diagnose and sell oxygen sensors. To illustrate the difference, let’s remember that an oxygen sensor replacement used to be
OHC Engine Repairs and Service on Chrysler’s 3.5L V6
Chrysler’s 24-valve 3.5L single overhead cam V6 engine was introduced back in 1993 in their LH platform cars (Chrysler Concorde, Dodge Intrepid and Eagle Vision). Since then it has been used in a variety of Chrysler models. The 3.5L engine is an even-firing power plant with aluminum cylinder heads, a single camshaft in each cylinder
Searching for the Diagnostic Path
Most recently, I’ve found myself dealing with an increasing number of random, multiple-code complaints that involve computer operating strategies and networking communications issues in which the multiple trouble codes or DTCs tend to be symptomatic, rather than indicative, of a component failure. A basic illustration of what I’m talking about is a simple DTC 44,
The Lube, Oil and Filter Market
As with everything else under the automotive sun, technology is changing the lube, oil and filter market. To be more specific, modern technology is making it possible to use the vehicle’s on-board engine management system to mathematically determine the length of an oil change interval. At the most basic level, the PCM simply adds up
Diagnostic Dilemmas: Playing the Diagnostic Shell Game
More often than not, deciphering diagnostic trouble codes is like playing a high-tech version of the old circus sideshow “shell” game. In the trouble code shell game, we are led to believe that the pea (diagnostic solution) is hidden under one of the shells (DTCs) stored in the diagnostic memory. Unfortunately for the diagnostic technician,
The Fuel Injector Market and System Configurations
Looking back into automotive history, it’s hard to believe that carburetors were still being installed on import vehicles as late as 1989! But carburetors require all sorts of external vacuum and electronic gimmickry to control the cold-starting, fast idle, hot idle and low-speed cruise functions. Electronic fuel injection has since replaced carburetors in all import