Category: TechAssist

Fundamentally, the anti-lock braking system (ABS) prevents skidding and loss of control under harsh braking. The Anti-lock braking system uses ABS Sensors (also known as wheel speed sensors) to sense conditions in the wheel which could result in a skid or loss of traction. But ABS sensors are also used by other vehicle systems aside from the ABS system including:

• Stability control
• Traction control
• Hill descent control
• Collision avoidance.

The rapid and accurate feedback from the ABS sensor is vital to an effective anti-lock braking and other safety systems.

The ABS sensor works in conjunction an ABS ring (sometimes referred to as a tone or pulse wheel) that is mounted to a component moving at the same rotation as the wheel. This is often the wheel hub but can also be the brake disc, CV joint or the drive shaft. The ABS sensor is mounted next to the ABS ring and communicates the rotational speed back to the ECU. The way in which rotation in measured depends on the type of sensor and ring in use. The most common sensors are either passive or active.

Lambda sensors were first fitted to cars in 1977 to improve the efficiency of combustion engines and help to reduce harmful exhaust emissions such as carbon monoxide.

Lambda sensors operate by measuring the amount of oxygen in the exhaust. An efficient engine requires a specific amount of air and fuel in it’s cylinders at combustion. The perfect ratio being 14.7:1 (14.7 parts air to 1 part fuel). This perfect mixture is called Lambda and this is where the unusual name originates. However, they are often also called oxygen sensors or O2 sensors due to their fundamental role of measuring oxygen. The levels calculated by the Lambda are sent as data to the ECU which then calculates and determines how best to achieve the ideal mixture of air and fuel at combustion.

An incorrect air/fuel mixture will be either rich or lean:

• In a rich mixture the air is high in unburned fuel, though low in oxygen.
• A lean mixture has the opposite balance and is high in oxygen due to not enough fuel being injected.

Many vehicles now feature a pre-cat Lambda Sensor and a post-cat Lambda Sensor. Whilst the pre-cat Lambda Sensor communicates to the ECU regulating the air/fuel ratio; the post-cat Lambda Sensor performs a diagnostic role, monitoring the Catalytic Converter.

Although seen on a daily basis, brake shields, otherwise referred to as dust covers, back plates or splash panels, are largely considered an irrelevance and generally ignored by technicians, as they undertake their regular service and repair responsibilities. Perhaps the only exception is when they are sometimes removed on the misconception that without them brake cooling can be improved or benefit the vehicle’s aesthetics.

Wiper blades may not be something that we rely upon every day (especially through the summer months) but when we do need them, we need them to perform. Your wipers are all that stand between the assault on your windscreen and your driving vision, making them a critical safety component. However, the performance of your blades hangs in a delicate balance. The soft, supple rubber that sweeps away water so effortlessly is not so great at battling other environmental factors. Faced with an onslaught of road tar, tree sap, cleaning chemicals, insects, oils from exhaust gasses and damaging UV rays, wiper blades can quickly deteriorate and that simple, easy-going component becomes the bane of your driving experience. Streaking, chattering, smearing and noise are all common and whilst replacing the old blades can often cure all of these complaints, it is not always the answer. Garages and motor factors frequently report new blade customers returning and reporting the same issues. ELTA believes that in these cases, the root causes of the symptoms have been missed. Here we look at some of the most common wiper blade complaints and identify possible causes and recommended solutions and additional checks to ensure that higher levels of customer satisfaction are achieved.

The Fuel Vaporizer is a relatively new component designed to improve the DPF regeneration process and further reduce harmful emissions.

The brake pad wear sensor is a simple component that plays a critical role in vehicle safety. In this bulletin we look at the brake pad wear sensor in depth.

There is a multitude of factors that affect how quickly brake pads wear. Varying driving conditions, speeds and pad compounds make it difficult to predict the lifespan of the brake pad. What we do know,is that below a certain level of wear, the effectiveness of the brake pad reduces significantly. The challenge faced by vehicle manufacturers is how to alert the driver once brake pads reach this point.