Auto Diagnostic Codes
Breaking Out the Box: DLC Diagnostic Strategies

An OBDII connector or DLC is designed to test emissions and create a standardized method and language of communicating with the emission control system. The connections in the OBDII DLC represent networks, power and sensor (signal) grounds.

Maximizing Tools: Simple Answers to Difficult Questions: Troubleshooting Complex Systems

A good diagnosis and repair relies on the experience, knowledge, flexibility of mind and logical thinking skills of the technician.

Using a Scan Tool and Meters To Diagnose Toyota Charging Systems

If, after replacing the alternator, a customer’s Toyota returns to your shop with the battery warning light on, contributor Gary Goms advises, “connect a scan tool to determine the charging system configuration and help analyze charging output.”

Humble Mechanic Volkswagen Check Engine Light Diagnosis

Check out Charles’ diagnosis on his own VW Passat when the check engine light came on recently.

Maximizing Tools: Using the CSS Script for Unconventional Diagnostic Methods

In order to successfully diagnose and repair different engine designs, a shop needs access to many different pieces of diagnostic equipment. In this article, the authors show and analyze examples of using your tools’ CSS script to diagnose vehicles.

U0100 Code: ECM/PCM Communication

In this Pulling Codes case, we document a U0100 code – a no communication issue with the PCM on a 2010 Dodge Caravan. With scan tools and scopes, contributor Carlton Banks diagnoses and solves the vehicle’s mysterious issues.

Maximizing Tools: It’s Just A Phase; Oscilloscopes Help Find Intermittent or No-Code Problems

As cars become more technologically advanced, the number of electronic units, sensors and actuators steadily increases. However, control modules may not recognize all faults. In order to accurately and correctly diagnose problems, it may be necessary to rely on data from a DMM or an oscilloscope.

Failed Honda PCMs And CAN System Diagnostics

In early 2014, Gary Goms received one of his most challenging e-mail requests from a shop foreman of a Honda dealership. This service manager had read a column he’d written on PCM diagnostics for ImportCar and was asking his opinion about why three PCMs would consecutively fail on a 2002 Honda Civic equipped with an automatic transmission with 137,000 miles on the odometer.

Sorting Through Multiple Codes On A Chevy

Gary Goms looks at a vehicle with 11 DTCs to find the root cause of the problem. This article discusses the art of deciphering codes and physical problems that may generate multiple codes and hide the real source of a problem.

Pulling Codes: P00C6 – Direct And To The Point

In this month’s Pulling Codes case, Contributing Writer Carlton Banks addresses a direct injection fuel pressure code (P00C6-Fuel Rail Pressure Low during Engine Cranking). The owner of a 2012 Chevrolet Impala states it appears to lose power at times. After the vehicle runs for quite some time, the power issue appears to go away.

Using an Oscilloscope to Diagnose DTCs

When our writers found that the P2716 Pressure Control Solenoid “D” Circuit DTC was common on Toyota Corollas, they decided to share their diagnostic journey with our readers.

Pulling Codes: 7 Common Causes of Misfire Codes

A flashing check engine light and a P0301 to P0312 DTC is a surefire indication that one or more cylinders are misfiring. Occasional misfires may pass unnoticed, but a steady misfire is hard to miss.