Driveability Archives - UnderhoodService
Drivability Issues Fuel Trim Diagnostics

No code diagnostics are some of the most challenging drivability issues.

Driveability Diagnostics And Direct Injection

Direct injection can be a diagnostic challenge, but with the right foundation, problems can be solved profitably.

Turbo Tools: Boost Drivability, Diagnostics

The two most important parameters to look at are the desired boost pressure and actual boost pressure during a test drive.

VIDEO: The Most Overlooked Brake Master Cylinder Replacement Part

If the seal or O-ring is leaking, it can cause a driveability issues with poor idle quality and lean DTC codes. Sponsored by Auto Value and Bumper to Bumper.

Ford: Driveability issues due to water in the PCM

                Some 1999-2003 Windstar and 2004-’07 Freestar /Monterey vehicles built prior to June 22, 2006, may exhibit engine/transmission driveability issues due to water entering the powertrain control module (PCM) or transaxle vent. The water leakage may be due to the PCM connector cover not seating completely and water

Ford Taurus PCM
Driveability Diagnostics and Direct Injection

Direct injection is becoming standard on more and more late-model vehicles. These systems can be a diagnostic challenge, but with the right foundation, problems can be solved profitably. Years ago, all a low-level technician needed to diagnose a fuel problem was a set of “noid lights,” a fuel pressure gauge and maybe a meter. These

Direct Injection Fuel System
Nissan Diagnostics: Check Engine Light And Misfire Issues

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.

Secret Diagnostic Trick: Hint? You Are Doing it Right Now

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.

Mazda Feature: Driveability And Check Engine Light Diagnostics

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.

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.

Pulling Codes: A Mercedes-Benz Story – A P0300 Analysis Using Exhaust Waveforms

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.