Last month, we outlined how to install and program a powertrain control module (PCM) on a Ford vehicle where the original PCM did not communicate using the PCM label. This month, we will cover using Fords As Built data from the Ford website. As Built
In this month's column, we will be covering tips, tricks and difficulties of some Chrysler V6 Crankshaft (CKP) and Camshaft (CMP) position sensor pattern relationships. Chrysler has used several different ECMs and PCMs on its 3.8L, 3.5L, 3.2L and 2.7
This month, we will take a look at those devilish defects known as "sneak circuits." A sneak circuit is any defect in a certain circuit or component system that affects another seemingly unrelated circuit or component system. Most of us have experien
This month we are going to share some real world lessons learned during extensive use of several different types of electrical test probes. I have used many different probes over the years and come to the conclusion that no one probe is best suited f
Airbag and seat belt detonator assemblies don't use a separate removable resistance sensor. However, they do have an intrinsic resistance value that the airbag ECU uses to sense a defective airbag circuit. With that in mind, we can substitute a pot i
Many shops are delving into ECU programming work these days. Beginning here, we are going to run a series of tips and tricks I have learned that will help you through some rough spots in these programming procedures.
This month, we are going to cover a specific test for analog output style Mass Airflow (MAF) sensors utilizing our test potentiometer (pot). We often need to find out if a MAF sensor is floating in and out of calibration causing an unsteady or surgin
Every vehicle has quirks about it. Some just have more than others. Check out these stories about higher-end vehicles, a BMW and a Jaguar to be specific, and the lengths these techs went to for a proper, accurate diagnosis.
Checking for power at panel mounted fuses and relays sounds like a straight forward proposition, right? What follows is some of the information you need to be aware of when playing the find the power game on modern vehicles.
The first time I ran into this doozy of a problem, I was lucky in that a friend and fellow mobile diagnostics professional knew exactly what the problem was. John Thornton out of Chicago saved my bacon on the first one. I have since seen this defect
This is one timing belt job you don't want to cruise too quickly through. It is extremely common for technicians to misalign the crankshaft and camshaft gear timing because of poorly represented timing mark diagrams in some service information source
Airbag and seat belt detonator assemblies don?t use a separate removable resistance sensor, however they do have an intrinsic resistance value that the airbag ECU uses to sense a defective airbag circuit. With that in mind, we can substitute our pote
When it came to knowing exactly how fast our vehicles were traveling down the road, the technology went from gear and cable driven speedometers to electronic speedometers based on a Vehicle Speed Sensor's (VSS) electronic signal output. The VSS was t
This month we will cover testing techniques used to diagnose three wire sensor circuits that vary their resistance in order to output information to an ECU. While there are several types of resistance based three wire sensors that operate differently
Many shops will attempt to save the owner of an older vehicle a few dollars by installing Engine Control Modules (ECMs) acquired at a salvage yard or rebuilder. The unknown history of these parts can present challenges to the repair shop. A difficult
Many sensors correlate physical changes in the position of vehicle components to changes in the resistance of the sensor itself, there by changing the amount of signal voltage in the sensor circuit outputs to the ECU.Knowing this, we can use a simple
Probably since there have been spark ignition engines, there have been ways to set and/or measure when the spark happens inside the combustion chamber. Using a light shining on the crank balancer was the easiest method to check spark timing once. Usi
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