Virtualmechanix.co.uk Diagnostics

Onboard Diagnostics - An Introduction

Sun, 09 Nov 2008 22:07:46 +0100

Diagnostic fault finding. The good news is Diagnostics can be carried out by anybody who can grasp a basic understanding of how electricity flows and the ability to follow a logical set of steps. When practiced, those simple steps will become your Diagnostic routine and when carried out correctly successful repairs will duly follow. Throughout the sections of the site you will find a brief description of the system to be tested and a set of...

Diagnostic Testing

Mon, 10 Nov 2008 00:00:00 +0100

Diagnostic fault finding isn’t just for the highly skilled. It is for anybody who can grasp a basic understanding of how electricity flows and the ability to follow a logical set of steps, that if practised will become your Diagnostic routine and when carried out correctly successful repairs will duly follow. Throughout the sections of the site you will find a brief description of the system to be tested and a set of techniques to successfully...

Health and Safety When working on a Motor Vehicle

Tue, 11 Nov 2008 00:00:00 +0100

When carrying out any work on a vehicle no matter were it is, you should always keep a thought for safe working practices. Garages, Workshops and vehicles all have their dangers and accidents are always waiting to happen. Fuel, Gas, Oil,Electricity, water, running engines and fast moving parts are all lethal when not treated with respect. The following are some simple points. It i by no means a complete list but you get the idea....

Engine Sensors

Tue, 11 Nov 2008 00:00:00 +0100

Air Flow Meter - Air Mass Type

Wed, 26 Nov 2008 20:40:11 +0100

The Mass Airflow sensor is used to measure the amount of air drawn into the engine. It consists of 3 main parts a Thermistor, a platinum wire and a control unit. Platinum hot wire. This is kept at a constant temperature by the control unit. The hot wire is cooled by the incoming air and the control unit increases the current to maintain it's temperature. The change in current is used as...

Air Flow Meter Vane Type

Wed, 26 Nov 2008 21:24:02 +0100

The Mass Airflow sensor (Vane Type) is used to measure the amount of air drawn into the engine by means of a hinged Flap. It has the following parts. Hinged Flap. This is connected to a potentiometer. The incoming air moves the flap and this moves the contact along the potentiometer. The different resistance is converted into a signal voltage and is sent back to the Engine Control Unit....

Distributor Hall Effect Type Used to show Engine Speed and Cylider Recognitionr

Sat, 29 Nov 2008 21:47:03 +0100

The Hall effect type Distributor Provides the speed and the cylinder potion of the engine. This type of Distributor replaced the earlier Points type Distributor. The Hall effect sensor is a simple switching circuit. The circuit is switched by a hall chip. The Hall Chip is located adjacent to a magnet and a drum mounted to the Distributor shaft rotates between the magnet and sensor. There are cut outs in the...

Engine Coolant Temperature Sensor

Sat, 29 Nov 2008 22:46:28 +0100

The Coolant temperature sensor is often a 2 wire type. It is a Negative Temperature Co efficient Sensor. Meaning when the temperature of the engine increases the Resistance in the sensor decreases. The Coolant sensor is a Resistance circuit. It provides a signal voltage back to the Ecu which is mainly used for fueling. The are the 4 terminal type sensors which are 2 Resistance circuits in 1 sensor. 1 circuit may...

Crankshaft Sensor, Crank Angle Sensor or Engine speed sensor

Mon, 01 Dec 2008 20:47:54 +0100

The Crankshaft Sensor is used to measure engine speed and Crankshaft position. It can be seen fitted into the block of the engine adjacent to the crankshaft, towards the Flywheel, by the front pulley or inside the distributor. The crankshaft Sensor is critical to the stating of an engine. A failed sensor will give you a no start situation. The Crankshaft sensor is an inductive type sensor. It consists of a...

Lambda Sensors Zirconia and Titania type Sensors

Thu, 04 Dec 2008 23:07:33 +0100

The Lambda Sensor is responsible for monitoring the oxygen content in the exhaust gasses from the engine. It is used mainly for 2 functions. The first is for fuel economy and the correct running of the engine. The second is to ensure the catalytic converter is operating correctly.There is little point in an engine burning more fuel than it need to. A Rich fuel mixture is very damaging to the Catalytic converter and a lean mixture...

Manifold Absolute Pressure Sensor - Map Sensor

Fri, 05 Dec 2008 21:45:19 +0100

The Map sensor - Manifold absolute pressure sensor is used by the Engine control unit to measure the air intake vacuum and pressure. The Map sensor sends a signal voltage back to the Engine control unit which it uses to help calculate the fueling and ignition for the engine. The Fueling is altered my means of the injection duration and the ignition is either advanced or retarded. The Manifold Absolute Pressure...

The History of Onboard Diagnostics OBD1, OBD 1.5 & OBD11

Sun, 07 Dec 2008 21:38:08 +0100

In 1970 The United States Congress passed the Clean Air Act to help reduce the worlds smog problems. Car manufacturers started to introduce electronic components in to carburetors in a bid to achieve the lower emission standards and maintenance free ignition systems were entering mass production. Diagnostic Link Connectors (DLC's) were being introduced to vehicles so sophisticated test equipment could be connected. This enabled a mechanic to monitor the running of an engine and also to...

OBD2 Diagnostic Socket (DLC) Information

Wed, 17 Dec 2008 22:51:18 +0100

The OBD2 Diagnostic Socket (J1962) referred to as the DLC (Diagnostic Link Connector) is now the most common type of diagnostic connector used. It can be seen fitted to most vehicles from 1996 onwards. As seen below it consists of 2 rows of 8 pins and is normally located within approximately 90 centimeters of the driver. It can be located under the steering column, in one of the kick panels or around the center console...