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
Advanced Brake Diagnostic Tools
Brake technicians are only as good as the tools they use. I have lived by this statement for a long time and it only makes sense, right? Well, what if I say the most important tool a brake technician has is his mind. The mind is a powerful tool when equipped with the right information,
Volvo Service And Driveability: Ways to Simplify Repairs and Promote Maintenance
Keeping a record of scheduled maintenance and service repairs is probably the best selling feature when the time comes to trade or sell a vehicle. You know the type: They baby their car, and their friends and family want first dibs when they decide to sell it. In most cases, that level of upkeep is
OBD II Diagnostics: Checking into Mode $06
In this scan tool diagnostics article, we take a look at Mode $06 functions which govern non-continuous monitors (EVAP, catalyst, EGR, etc.)
Mastering Mercedes Multiplexing
“CAN” is the new buzz word in automobile diagnostics. It stands for Controller Area Network and is a protocol for onboard diagnostics and scan tools. CAN is a high-speed data link that provides more information at a faster rate for better communication between onboard electronics and external diagnostic equipment. Many manufacturers have already started incorporating
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.