Diagnostics Archives - Page 36 of 41 - Brake & Front End
Time and a Half

One of the hot-button issues in the independent automotive service industry is how to charge for diagnostic time. Currently, the debate is framed by two basic schools of thought. The practitioners of the first school are the shop managers who regard “free diagnostic code reads” as a marketing expense needed to lure potential customers into

Current Trends for Ignition Systems

As automotive technology moves forward, ignition systems are becoming more and more entangled with other systems on the engine. The current generation Nissan Maxima 3.5L V6, which was introduced in 2004, has a fairly conventional coil-on-plug (COP) ignition system. The individual coils are driven by the powertrain control module (PCM) using the input signal from

Wheel Speed Sensors Replacement: WSS, Chevy, GM

By Larry Carley, Technical Editor When engineers came up with the idea of putting the wheel speed sensor (WSS) and tone ring inside a sealed wheel bearing hub assembly, it seemed like a great idea. The sealed environment would help protect the sensor and make it less vulnerable to damage or contamination from the outside

Tech Feature: Engine Diagnostics…What to do When an Engine Won’t Start

In today’s world of high-tech electronics, onboard diagnostics and scan tools, you would think engine diagnostics would be easier than ever. Yet some technicians struggle when confronted with an engine that cranks but refuses to start. Most no-starts do not generate any fault codes, so how do you proceed to find out what’s causing the

Diagnostic Dilemmas: Got a Light?

Every diagnostic technician experiences operational complaints that are more bizarre than they are technically complex. The problem is made difficult when the technician fails to stand back from the problem and look at what I call, “The Big Picture.” As you will see in the following case study, The Big Picture is a collection of

Diagnostic Solutions: COP Ignition Systems

For a number of reasons, the trend of modern engine management technology is leaning toward using coil-on-plug (COP) ignition systems. One reason is that COP ignitions are very compact and are very adaptable to individual cylinder tuning. With the exception of a few designs that incorporate a driver or “module” into the COP assembly itself,

Decoding the Past

“I’d like for you to hook it up to the code machine and see what it says to replace” – anonymous customer Sound about right? It sure does. Of course, as auto repair professionals, we know better. We know that reading the code is not diagnostics, but rather that is where diagnostics might begin. We

Automatic Transmissions: From Mechanical to Electronic to Hybrid

A long time ago in a service bay, preventive maintenance for an automatic transmission was an oil change, band and throttle linkage adjustment. The 1960s saw the end of external band adjustments. In the 1970s, the drain plug went away and the pick up screen was replaced with a filter. In the 1980s, a turbo

Diagnostic Solutions: Cylinder Head Service, Restoring the Engine to Precise OE Tolerances

Although cylinder head repairs have been a staple of the import repair shop for many years, modern technology has changed the way we should sell and perform cylinder head services. In years past, for example, a cylinder head repair need last only 30,000 or 40,000 miles until the vehicle was retired from service. Today, however,

Diagnostic Dilemmas: Temperature Tantrums

Solving temperature-related, no-code intermittent failures can be a frustrating experience for the diagnostic technician because the exact level of heat or cold needed to trigger the failure is often hard to duplicate. It’s also important to keep in mind that all electronic vehicle components are exposed to temperature extremes and thus are vulnerable to temperature-related

Who’s at Fault?…Top 10 Domestic Diagnostic Codes & Fixes

A Check Engine Light that’s illuminated is always a sign that something is wrong. But what? You usually can’t tell until you plug in a code reader or scan tool and read out the code(s) that have turned on the light. At least then you have a starting point for further diagnosis. Some people think

Scan Tools: Scan Tools Offer a Window Into a Vehicle’s Inner Workings

Scan Tools Offer a Window Into a Vehicle’s Inner Workings Larry Carley, Technical Editor [email protected] Technicians who attempt to make driveability or emissions repairs today without a scan tool are troubleshooting in the dark. A scan tool is absolutely essential because it provides a window into the inner workings of the engine management and onboard