Driveability Archives - Page 8 of 13 - UnderhoodService
Perspectives: Positive Service Implications from a Sophisticated Aftermarket

Arming consumers with vehicle information gives them a better understanding of the importance and complexity of the various automotive systems

Tech Tip: Kia Throttle Body Cleaning

Some Kia drivers may complain of an engine that is hard to start, or that won’t start at all. DTCs P2110, P2118 or P2119 (throttle valve stuck closed) may be present on Theta 2.0L/2.4L engine-equipped vehicles. The condition may occur from carbon deposits and/or fuel additives accumulated in the throttle body.

Tech Feature: MIL Diagnostics and Driveability

MIL diagnostics continues to be a “hot” topic for many import shops simply because the definition of the word continues to change. Looking at the history of modern vehicle diagnostics, most veteran technicians can remember the days when vehicles had no on-board diagnostic systems and, subsequently, required time-consuming pin-out procedures to diagnose electronic systems failures.

Tech Tip: Infiniti DTC P0505 Due To Incorrect Idle Speed

If one of the applied vehicles above has a DTC P0505 AAC/V stored, with no customer driveability incident, it may be caused by an elevated or incorrect engine idle speed setting. In some of these cases, the Idle Air Volume Learning (IAVL) procedure should be performed to resolve the incident. Use the Service Procedure outlined in this Tech Tip to identify and address this incident.

Tech Feature: Diagnosing Automotive Lab Scope Dilemmas

Although digital storage oscilloscopes or “lab scopes” have now become standard equipment for most modern automotive repair shops, they still possess a mystique that tends to intimidate many technicians. Right off the top, a lab scope is basically a voltmeter that displays voltage signals along a time base. The vertical scale measures the amplitude or amount of the voltage and the horizontal scale measures an incremental time line along which the signals are displayed.

Using OBD II Diagnostics to Communicate with Your Customer’s Volkswagen

This article is about communication faults and problems that have occurred on Volkswagens over the last 10-plus years. Many of the same problems still exist on the newest models, but as these vehicles age, get repaired or damaged, problems come up that can challenge even the very best technicians.

Directions: Will Driver Awareness on Recalls Drive Up Shop Stops?

While new car recalls have been among the biggest news stories of the year, an analysis by, assures consumers that despite these recent headlines, recalls were much more of a concern in decades past.

Finding Check Engine Light Culprits on Nissan Models

This month, we’ll be taking a look at the Nissan line and some of the common causes for the check engine light to be lit, as well as some of the driveability problems that may result.

Tech Tip: Nissan Altima, Sentra with MIL On and DTCs P0100/ P0102/P1102 Stored

If you confirm that an applied vehicle has DTCs P0100/P0102/P1102 stored and may also exhibit a rough-running engine, slight engine speed variation while driving or low engine power, follow the procedures outlined below.

Mitch Schneider: How to Pass the ‘Reasonable Man’ Test

We’ve been doing a fair amount of restoration work lately. Certainly, more than we’ve done in a very long time: a 1962 red Corvette convertible (Like there is another color…), a number of vintage ’50s and ’60s Cadillac Coupes and Sedan De Villes, a few early ’50s Roadmasters, a couple of classic ’60s Mustangs, a 1931 Oldsmobile (I know…How did that one sneak in there?) and more.

Tech Feature: Diagnosing Ford Exhaust Gas Recirculation System Problems

To diagnose and repair Ford exhaust gas recirculation (EGR) systems properly, it is important to understand how they work and what is unique to the product line.

Tech Feature: Lack of Power Leads to Exhaust Restriction Analysis

In the early days of carburetors and mechanical fuel pumps, most lack-of-power complaints stemmed from vapor locking on the fuel pump or the fuel filter clogging. But that’s becoming the exception rather than the rule.