ReFlashing Control Modules
You don’t have to be Microsoft A+ certified to flash reprogram automotive PCMs, but the process requires a certain amount of know-how as well as special tools and access to the latest OEM software upgrades. What’s more, it’s not a risk-free endeavor. Certain precautions must be undertaken before you begin, and there are pitfalls that
PCV Service: Helping an Engine Catch Its Breath
I’m certain that each and every one of you have, at some time in your life, experienced the horrific event of having the wind knocked out of you. If you can remember back to the first time it ever happened, before you knew that you would, in fact, breathe again, it was like you were
Update On CAN Diagnostics
Whether you like it or not, Controller Area Networks (CAN) have taken over. CAN technology has been steadily creeping into more and more new vehicles since it first appeared in 1992 on certain Mercedes-Benz models. Thanks to federal emissions rules, it is now required on all 2008 model year vehicles, and will be forevermore. What
Tech Feature: Gaining Access to Perimeter Anti-Theft Systems
It could use the same acronym, but is perimeter anti-theft the same as PATS? No, PATS, which stands for passive anti-theft systems, is a system that is designed to identify the key, and was discussed in the July 2007 issue of Underhood Service. Perimeter anti-theft is a system designed to identify unauthorized vehicle entry. There
Replacing Hubs with Wheel Speed Sensors
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
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
Oxygen Sensors: Pulse Measurement
Watching an oxygen sensor output on an oscilloscope is like watching a sporting event on television. You get to see the action, but can do nothing about it as it happens. Sometimes you miss the action and want an instant replay. It was a bad call. You saw the interference. If the referee didn’t see
Predicting Failures
spect that at one time or another, we’ve all had a customer return with a check engine light on with a new fault code that wasn’t there last time they were in. The events probably went something like this: Customer: “You couldn’t see that when you looked at it last time?” Shop: “No ma’am, there’s
Diagnostic Dilemmas: Symptom Diagnosis…The Journey Begins
When I first began my automotive career way back in 1957, the symptoms of an ailing engine were very apparent. A carburetor with a worn accelerator pump, for example, would characteristically stumble on acceleration and a closed-up set of distributor contact points would cause the engine to become very sluggish. Low fuel pressure caused by
Foreign Affairs: Getting Nissan Engines Back to Peak Performance
/Articles/06_01_2007/60754gif_00000014067.gif” width=”156″ height=”146″ alt=”” border=”0″ align=”right” /> In this article, we’ll take a look at some of the common problems that affect engine performance. With on-board diagnostics (OBD), many of these problems will cause a check engine lamp (CEL) and store a code. With most of us becoming comfortable and proficient while working with OBD
Mercedes: Deciphering Driveability Dilemmas
As the oldest surviving automotive manufacturer on the planet, Mercedes-Benz has developed a reputation for superior engineering and quality. Models with new features and mechanical developments have been consistently introduced for more than a century. For the automotive technician, this line of vehicles has been a source of never-ending education. Innovation after innovation has challenged
Diagnostics Through CAN Networks
Since model year 2003, a growing number of domestic and import vehicles have been built with a new onboard communications protocol called CAN (Controller Area Network). CAN is essentially an engineering standard for how computers and modules talk to one another via the serial data bus in a vehicle’s wiring system. It’s a high speed