The late-model Nissans have proven to be quite reliable when it comes to serial-type problems that would get them to your bay with check engine lamp issues. Nissan has done a good job of addressing some of the problems we’ve looked at in the past. But that doesn’t mean you won’t be seeing Nissans looking for attention, and that spells service opportunities for you.
I was fortunate to have been raised in my father’s auto shop. From the early age of 11, I could be found performing various tasks around the shop from cleaning to observing and helping the technicians whenever an opportunity would arise. I now have my own one-man auto repair facility where I am the only person involved with the repair process of the vehicle. This mandates me making the most efficient use of my time. So, over the next several articles, it is my plan to share with you some of my time-saving diagnostic strategies.
Import Specialist Bob Dowie takes a look at some of the more common ailments that will bring your Mazda customers into your service bay with a check engine light complaint, as he covers common DTCs, stalling and ignition issues and new technology.
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.
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.
This article will document the P0300 code for a 1996 Mercedes-Benz. A single cylinder misfire has occurred, and the technician decides to clear the code in my presence. I advised that it is a good strategy to maintain the code information for review. It’s clear that misfire activity can be challenging on some ignition systems, and I’ve found through my research that all of the car manufacturers appear to run their monitors in a similar fashion, but it’s still wise to review their service information for the differences and details of their systems.
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.
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.
When you hear the name Cummins, what is the first thing that comes to mind? Most of the time, if you have any knowledge of trucks, a Dodge truck is the first thing that comes to mind. The Cummins diesel engine has always had a great reputation for reliable diesel power. Though the Cummins diesel engine can be found in many applications, it seems to obtain most of its credit from drivers of over the road trucks.
If you encounter a Dodge with a P2767 trouble code set, check the wiring between the transmission and the transmission control module. Make sure the #2 signal wire is not open, shorted to ground, or shorted to any other circuit. If the wiring checks OK, raise all four wheels off the ground, start the vehicle and place the shifter in drive. While lab scope testing the #2 signal wire, obtain second gear. When the transmission is in second gear, there should be a 5-volt square wave pattern being produced by the #2 sensor. If not, replace the sensor.
Hall effect crankshaft position (CKP) and camshaft position (CMP) sensors are critical components of an engine management system. The inputs they provide enable the powertrain control module (PCM) to determine engine speed and position including where a given cylinder is within the four-stroke cycle.
The misfiring cylinder must be identified through Self-Test misfire codes or through WDS Power Balance. Rule out base engine problems; rule out fuel problems; and then look at ignition problems (be sure to rule out coil primary circuit issues).