Diagnosing Variable Valve Timing
Fully variable valve timing can be achieved only by using computer-operated solenoids to precisely control the intake and exhaust valve opening and closing events. Although the various combinations of valve timing events are theoretically infinite on an electronically controlled system, their applications are limited due to issues of cost and, in some cases, reliability.
Diagnostic Dilemma: 1999 Dodge Dakota Intermittent Stall Complaints
Diagnosing intermittent stalling complaints is a challenging experience for any diagnostic technician because any number of electrical and mechanical failures can cause an engine to intermittently stall. Most of us immediately narrow this laundry list of potential failures down to the most common few, which include components like the crankshaft position sensor and electric fuel pump.
Cold Weather Diagnostics: Modules Go Down With The Temperature
The subject vehicles were 2002-2006 Ford trucks – the first was a 2002 Ford F-150 with a 5.4 liter, second was a 2006 Lincoln Navigator with a 4.6 liter and finally a 2004 Ford F-250 with a 5.4 liter engine. All of the customer complaints with these vehicles were the same: “The vehicle will not crank/start when cold.”
Audi Tech Tip: MIL On With P1545, P0121, P0123, P0221 Or P0222 Stored In ECM
The MIL is on, with a number of incident memory entries with regard to the throttle valve are stored in the ECM. In most cases, the entries are sporadic. This may be the result of contact resistance in the ECM wiring – throttle valve.
Tech Tip: Nissan Xterra Hesitates Upon Acceleration
The technician connected a scan tool and found code P0102 – Mass or Volume Air Flow “A” Circuit Low. He then performed an inspection of the mass airflow (MAF) sensor and related wiring harness, but found no obvious faults.
PCM Diagnostics Case Study: No-Code Misfire Diagnosis On A 1998 Toyota 4Runner
When doing mobile diagnostic work for other shops, contributing writer Gary Goms usually sees more than his share of random no-code engine performance complaints. In the following case study, the customer of a client shop complained about an intermittent rough idle on his well-maintained 1998 Toyota 4Runner, but only when it was driven in hot weather. The client shop couldn’t duplicate the complaint, no matter how long the engine ran. Of course, the lack of DTCs didn’t help the diagnostic process.
De-Coding Diagnostic Scan Tool Codes
I like to take full advantage of the codes the manufacturers offer. One of the ways to do that is to understand what all those letters and numbers represent that are in a diagnostic trouble code. Each of the five digits actually has a purpose and can make the job of diagnosing a vehicle’s problem much easier for import technicians if they understand the breakdown of the code’s letters and numbers.
Maximizing Tools: Unconventional Diagnostic Methods, Part I
Explore some unconventional uses of a digital multimeter that will allow you to diagnose problems without a significant investment of time and effort.
CARDONE Now Offers More Than 290 Previously Dealer-Only SKUs
CARDONE now offers more than 290 SKUs that were previously dealer-only, providing a high-quality, low-cost alternative to OE, the company says.
Tech Feature: Dissecting The Control Module – PCMs, TCMs And BCMs
With the complexity of automotive electrical systems increasing steadily, manufacturers have developed troubleshooting trees and strategies to make it easier for technicians to diagnose problems. These steps and strategies are very helpful for technicians when followed, but they can also prevent them from using their cognitive skills.
Mercedes: Diagnosing a P0301 Misfire Code Harnessing the Benefits of an Amp Probe
Electronics Diagnostic Specialist Sergio
Tech Feature: Controller Area Network (CAN) Bus Topology
At the typical repair shop, six-year-old vehicles (and there are 184 million of them on the road today) are some of the most common vehicles driving into the bays. And, since these vehicles are out of warranty, they will fuel service opportunities for the aftermarket and require more attention from independent repair shops like yours. In particular, one growing service area is diagnostics, especially as it relates to the expanding electronic content in today’s vehicles.