My EPC light came on

My epc light came on

Virtually every  motoring enthusiasts who owns a Volkswagen Golf TDI  simply loves its torque; its drive, its racy performance, its braking, its fuel economy and especially its manual transmission model. Be that as it may, 6 out of 10 Volkswagen and Audi owners are unhappy about Volkswagen as a whole. Unhappy about their cheating devices, unhappy about the emission scandal, unhappy about the entire VW TDI buy back claims processes, but more specifically unhappy about having to give back the car that they love so much.

According to the 225-page court document that outlines VW’s settlement, which reads,

“At the present time, there are no practical engineering solutions that would, without negative impact to vehicle functions and unacceptable delay, bring the 2.0 Liter Subject Vehicles into compliance with the exhaust emission standards.” 

This is so wrong on so many different levels hence most VW and Audi owners are completely pissed-off -pissed-off at Volkswagen. Event hough most VW TDI enthusiasts haven't returned their cars, they are already missing them, even before it's taken back; all of them very unhappy about it. It's always good to be optimistic about the buyback outcome but pessimistically speaking, VW, Audi, Seat and Skoda owner's are all complaining about their cars, ranging from, 

"My epc light came on and I lost power",  to 

"I got stranded on the side of the highway today for  almost an hour when my EPC light went on",  to 

"The first time it happened, the EPC light turned on and loss of  power lasted for a day and then it went away on it's own",  This is now the third time this happened, the EPC light comes on and then my car just loses power", 

"I took my car to the VW agents for a EPC problem who then said they  found a few error code but they didn't know what was wrong, so they just reset them",  

"Totally disgusted, by the dealer's complete and utter  disregard to accept responsibility for their pathetic  workmanship. They threw a dozen parts at the problem at my cost and the EPC problem is still not solved", 

I've kept track of all the faults on my VW Polo, and it fills a foolscap page.  It ranges  from interior parts falling off, the foot rest lodging itself under the brake pedal whilst driving, the brakes randomly engaging and causing under steer, to continual  creaks from the suspension, the gearbox is crap, not to mention my daily battle with an EPC issue. My Polo's been back to VW a full 58 days during this  year, yet they still haven't fixed all the issues and  as a result I very nearly caused 2 accidents due to  the on-going braking issue, and the EPC going  into limp mode on an on-ramp,  

I've spent more than a  year trying to solve  the problem “EPC” light problem, I've already  replaced  the Acceleration pedal, Two sensors located  under the engine, Cambelt kit, Throttle Body, all the  injectors and the ignition coils and the ECU,   but the light still regularly comes on,  

The VW guaranteed future Value a Rip-Off! I have never  been so dissatisfied with help from customer service and  will NEVER EVER purchase another Volkswagen nor recommend it to anyone I know, because of the shoddy  way we were treated. The staff working in VW credit and financial are rude and disorganized, no wonder they losing all their customers.They charged me for items covered by the warranty.

And the list goes on. These are only a few of the nice clients  I wouldn't want to repeat what some of the other "not so nice" clients said about Volkswagen and their cars, especially about the EPC light and limp mode. Electronic power Control (EPC) has become part of every VW, Audi, Skoda and Seat owners vocabulary, yet few understand what it really is. So allow me to put you in the picture.

Electronic Power Control

The EPC warning light is just a regular warning indicator light, much like your handbrake light or your oil indicator light.  The handbrake light just tells you that the hand break is engaged, alternatively that it hasn't been released. Likewise the oil light is a warning indicator that alerts the driver to the fact that the oil is low. In the very same vain the EPC warning  light is just an indication that something awry has happened in your Volkswagen's torque system, which is a sub-circuit of the Electronic Power Control Circuit.  

So what exactly is the torque system ? you may ask. Well is consists of various interlinked components, where the functionality of one is subject to another. These components are your  Volkswagen's entire drive-by-wire system, incorporating the  accelerator pedal, the throttle body, the cruise control, the traction control, the breaking system, the fuel pressure system, the knock sensors and the ECU, along with the wiring harnesses that inter-connects all these components. The wiring harness is a safer substitute for accellerator cable in all drive-by-wire systems.  

The accelerator pedal

The accelerator pedal for that matter, has 2 independent potentiometers inside a module that's permanently bonded to the pedal itself. These 2 potentiometers are call senders by Volkswagen and known as G79 and G185, but I will use these terms interchangeably.  This module is connected to the ECU via a 6 wire harness, essentially 3 wires per senders. Before, I continue, let me tell you what a potentiometer is, if you not familiar with the term. Another name for a potentiometer is variable resistor or a rheostat. It is most commonly used as rotary the control knob on a radio, with which to control the level of its volume. It is also commonly used in  the bedroom light dimmer to adjust the level of light needed. 

Each sender has 3 pins, 1 for each end of its resistor and 1 pin for its wiper. All three pins of each sender are connected to 3 pins specific pins of the ECU. The ECU sends each sender a high and a low voltage across their resistors and receives a difference fed back voltage from each sender's wiper. The 2 wiper feedback voltages are referenced and inverted to one another and translated by the ECU as how much the accelerator pedal is depressed.  Should  the ECU loose either of the wiper inputs for even a fraction of a second, the ECU limp mode program will execute, the EPC light will come on and the engine wont rev higher that 2000 rpm any longer. When my EPC light came on, I traced it back to a fault/ intermittent accelerator pedal due to error codes P1630  to P1634 and P1639.

The throttle body

Much like the accelerator module, the throttle body also has 2 integrated potentiometers called angle sensors known as G186 and G187. They inform the ECU how wide open or closed its butterfly is. The throttle body also has a built-in stepper motor known as an actuator. The ECU essentially translates the accelerator pedal position to a voltage / pulse train that drives the stepper motor, that in turn opens and closes the throttle body butterfly, controlling  air flow between air filter and intake manifold.  In a nutshell, a remote control system that mimics the operation of an accelerator cable. If for any reason the throttle body is removed or dismantled, it would be necessary to perform the adaptation procedure. When my EPC light came on, I traced it back to a  throttle body problem with error codes P1171 - Angle Sensor 2 for Throttle Actuator (G188) Implausible Signal.

The cruise control

When the cruise control is enabled, a signal is sent to the ECU to this effect, which in turn sends the necessary voltage / pulse train to the throttle body stepper motor to keep it steady and received feedback from G186 and G187 to further control the process., ignoring the accelerator pedal until the brake is applied or receiving a signal change from the accelerator pedal. Should something go awry in this process, cruise control will be canceled, the ECU limp mode program will execute, the EPC light will come on and the engine wont rev higher that 2000 rpm any longer. When my EPC light came on, I traced it back to a  cruise control switch problem with error codes  00895 - Cruise Control Switch (E45) Defective.

Volkswagen Ignition System

Did you know that the electronics industry has had the fastest growth in the shortest amount time, compared to all other industries worldwide? But  before I expound on that, let me just say that, the invention of numerous mechanical contraptions during the late 1800s, like James Watt's steam engine for example, started the transition towards new manufacturing processes which collectively gave rise to the industrial revolution. Much later Samuel Finley Breese Morse invented the single-wire electric telegraph system and developed the Morse Code. And sometime thereafter Alexander Graham Bell invented the first practical telephone system and their collective efforts, without discounting anyone else's efforts, changed telecommunications forever. 

Added to this, ancient records show that the first streets of Baghdad were paved with tar, and that the Babylonians used asphalt to construct the walls and towers of Babylon. Even The I Ching bears testimony to the fact that the cites of China used oil extracted in its raw state before refining was first discovered, during the first century BCE. By implication, tar, crude oil and pitch, were used as a sources of fuel for a very long time before paraffin was distilled from it. When this finally happened, the thin distilled paraffin was commonly used as fuel for lamps whereas the thicker residue was used to lubricate machinery. Soon after or in and around this time, when oil/fuel was extracted from coal, Étienne Lenoir successfully innovated the internal combustion engine followed by Nikolaus Otto who became famous for successfully developing the compressed charge internal combustion engine - the Otto engine. 

Now Henry Ford on the other hand wasn't an inventor nor an innovator, by any stretch of the imagination, as many are led to believe. He was rather a  business magnate and a captain of industry, who formed the Ford Motor Company, and sponsored the development of the "assembly line technique" for vehicle mass production. One could clearly say that their collectively efforts, without diminishing any other contributor's efforts by the very least, over a period of some 200 years, are partially responsible for the social changes and economic development that shaped societies that we live in today. 

Electronics

However, when the mechanical inventions of the Industrial revolution, is compared to modern day electronics, it stands out like a global coup. Initially there was the vacuum tube aka the electron tube, colloquially known as a valve. It gave way to semi-conductor devices as a whole. Transistors and gave rise to the analogue Integrated Circuits (IC) aka chip, followed by Transistor/Transistor logic TTL chips, followed by  digital semiconductors like complimentary metal oxide  semiconductors (CMOS) chips, ROM (digital read only memeory), RAM (random access memory) chips, EEPROM (electronically erasable programmable read only memory) chips. 

This was followed up by large scale integration (LSI) chips and Very Large Scale Integration Chips (VSLI ) chips. With the advent of multi-layer circuit boards and surface mounted technology, microcontroller (system on a chip) SoC and  microprocessors (µP) became pervasive. Assembler language for chip families was developed and compiled to high level languages for programmable chips while software programming sat at the heart of most electronic devices and electronic systems. Communication protocols were developed and networks of various types became mainstream. All of this happened in 50 years as opposed to 200 years as mentioned above.

Volkswagen Ignition System

So you may ask, what has all this history to do with Volkswagen, Audi, Seat and Skoda and for that matter all vehicles from plains to trains? Well the short answer, everything! Much like the industrial revolution with its mechanical enginuity;  cars and planes were also predominantly mechanical since its inception, its mechanical Ignition System was prone to imprecise ignition timing, resulting in improper fuel mixture burn, thus increasing its exhaust pollution. With the rise of telecommunications of old, so did the electric wires, and electrically controlled gauges, and relays switches in cars and planes multiply.

The ever inflating cost of gasoline then triggered the invention of CDI (Capacitive Discharge Ignition Systems) which is in fact the first type of electronic contraption integrated into the Ignition System of a vehicle in order to, more precisely control its ignition timing making it more fuel efficient. These devices were available as add on kits and not produced as standard equipment in cars at the time. The preferred standard equipment was the IDI  (Inductive Ignition System) and is the most common Ignition System found on all cars built prior to 1980. It used a coil, distributor incorporating breaker points in its Ignition System that was prone to ware-out due to arcing on contact.

During the 80's engines still used a coil and a distributor but was computer controlled, and by the 90's the computer evolved to an ECU, replacing the coil with a power pack. However, with the constant and ever increasing price of gasoline and looming environmental concerns about vehicle exhaust pollution; the automotive industry then accelerated its R & D into newer and denser, more fuel efficient engines and power-train systems capable of higher power output with enhanced robustness. 

With the demand for higher-km/litre vehicles, Auto Ignition System needed to undergo an extreme revolution to produce a more  advanced Ignition Systems. So, by the 90's an Insulated-Gate Bipolar Transistor (IGBT) was introduced into the Ignition System as a discrete component connected to the ECU. It essentially replaced the bi-polar transistor used in older systems. 

Insulated-Gate Bipolar Transistor 

An Insulated-Gate Bipolar Transistor (IGBT) is a fancy transistor, a semiconductor that functions like a switch.  Unlike mechanical points, a semiconductor switch doesn't have moving contacts and is thus referred to as a solid state switch capable of handling Voltages between 600 Volts and 3300 Volts. So in a nutshell and IGBT is a fast solid state switch capable of switching speeds between 6 ns and 125 that and can be remotely controlled.  It is thus controlled by the ECU via a driver module. The 12V DC traverses the coils winding and its negative side is connected to the collector of the IGBT which switches it to earth giving rise to induction in its secondary winding that produces the spark. Switching on and off also creates heat in the collector/ emmiter junction, cable of withstanding maximum junction temperatures of 150°C and 175°C. So as can be seen, an IGBT its just a fancy transistor, it is the latest technology needed for engines to operate at higher compression ratios that need higher spark plug voltage that can emit greater energy to ignite lean air and-fuel mixtures.

Post Y2K  technology

Starting from Y2K Ignition Systems were all ECU based, but the power packs of the 90's were replaced by dedicated coils per engine cylinder,  yet making use of an Insulated-Gate Bipolar Transistor (IGBT) as discrete component but connected to the ECU. From 2004 to 2010 the discrete Insulated-Gate Bipolar Transistor (IGBT) integrated into individual Ignition Coils evolved to the all new Smart IGBT connected to the ECU. In later technologies the discrete / Smart IGBT evolve into a IGBT Module also integrated into each of the individual coils. 

What this implies, is that each spark plug have its very own coil completely independently switched by a Smart IGBT module driven by the ECU to an extremely tight tolerance. The ultimate objective is, that the ECU, whilst maintaining absolute  stoichiometricity,  triggers the Smart IGBT module that in turn fires the spark plug at the precise moment to attain  absolute combustion.

The accurateness of the entire ignition timing process is  determined by the ECU. Its internal programming tightly controls  ignition timing process yet subject to inputs from several engine sensors as well as engine speed, torque and  temperature. Should the spark occur too early, the resulting combustion chamber pressure, then applies force to the crankshaft before its force can be transformed into continued rotation. This could cause pre-ignition. Should the spark occur too late, the combustion chamber pressure peak weakens rapidly as the chamber volume rapidly increases as the piston moves downwards. This normally results in  incomplete combustion, causing possible  knocking.  Both pre-ignition and knocking are totally undesirable and the most common cause of hydrocarbons - unburnt fuel exhaust white smoke. This unburnt fuel igniting in either the intake manifold or the exhaust system would result in back-firing.

Ignition Error Codes

Any such undesirables would trigger a DTC error codes in the P0300 range. P301 misfire cylinder 1, P302 misfire cylinder 2, P303 misfire cylinder 3, P0304 misfire cylinder 4. This can be extrapolated up to P0312 for a 12 cylinder engine. In the same vane, every component involved in delivery of a spark to the relevant combustion chamber can cause misfires. The coil can present a misfire, the spark plug can cause a misfire, the  wiring  between the ECU and the coil can cause a misfire, the Smart IGBT module can cause a misfire, the IGBT driver can cause a misfire and even the IGBT itself can cause a misfire.

Volkswagen_Polo

Volkswagen_Polo

During the winter of 2018, the Western Cape hasn't received a similar volume of rainfall as it did in previous years, thus draining its reservoirs to its last 10%. So, due to water scarcity a drought alert  was raised, along with the price of water. Water restrictions were implemented, water was denied, rain water was caught in Jojo tanks by many. Grey water became a buzz word and people lined up at the aquifers to collect drinking water.  In a nutshell we had a water crises and much like the price of water, the price of fuel in South Africa is also staggering.

Staggering isn't perhaps the most appropriate word  to use in this case because in essence, staggering  implies stumbling, almost falling rather than constantly rising. So I'm going to resort to words like astonishing, outrageous even scandalous. Yet this hasn't impeded car sales in the very least because cars are being sold in huge numbers monthly, despite the economic situation in SA. Not to mention that President Zuma was impeached and removed from office causing both Moody's and S&P to downgrade South Africa's foreign and local currency to junk status. Then there is also South Africa's unemployment rate that borders on 27%, followed by its  crime statistics that has somewhat decreased by 1.8% comparative to 2015/16, inclusive of vehicle theft.

Meanwhile the VW Polo reigns supreme, as the most popular and best-selling passenger  car in South Africa, closely followed in second place by its cousin,  the Polo Vivo.  The Toyota Corolla, Auris and Quest sales comes in third place, closely followed by its cousin the Etios that took sixth place.  Then there is the Kia Picanto followed by the Renault Kwid followed by the Hyundai Creta. 

The importance of this observation is that all these cars are smaller  than the average medium sized family car. The expectancy is that being smaller, they would also be more fuel efficient but that's certainly not the case. It turns out that the Ford Fiesta 1.5 TDCi Trend, the the Fiat Tipo 1.3 Multijet Easy, Fiat 500, the Peugeot 2008 1.6 HDi Active and the Fiat Panda 0.9 TwinAir Easy are the most fuel efficient smaller cars on the road respectively. But their fuel efficiency is liked to impeded functionality, cramped seating with hardly any boot space.

Why Buy VW Polo

People buy VW Polo's for its sophisticated look and feel, its overall build quality and its youthful appeal, its comfortable seating and its lavish boot space. Polo also delivers superior performance and is more pleasing to drive. They are affordable both new and second-hand and cheap to insure. The Volkswagen Polo brand has been around since 1975 and is now in its seventh generation and is also sold as the Skoda Fabia and the SEAT Ibiza. 

It just makes economic sense to drive and own a VW Polo because its spare parts both used and new are in abundance. The Polo TDI BlueMotion takes fuel efficiency to a new level and is one of the most fuel-efficient non-hybrid cars in SA, employing the same 1,0-litre turbo triple as the Audi A1. Beside VW offers a three-year, 60,000-mile warranty as standard on every Polo. Though not as fuel efficient as the match-box Fiats mentioned above.

So, considering the ever rising price of fuel, its just a matter of time before every household would want to store some in Jojo tanks underground to get a reprieve from paying  these outrageous and scandalous fuel prices. If you want a fuel price alert when it increased .... and possible decreases, click here!