POWER CONTROL

ELECTRONIC POWER CONTROL EXPLAINED

As I mentioned in a previous, blog German Automotive Technology is really, really cool. German car design and automotive technology is currently at the forefront of going green, with the result that all other motor manufacturers are turning green with envy. Pardon the pun. German car design technology doesn't flaunt the colour green as eco-friendly but rather blue. 

Mercedes is pushing Blue Efficiency as their future technology and VW is flaunting Bluemotion as their new technology.  Polo de Volkswagen Bluemotion technology started out with the 2007 Polo (not my 2007 Polo Classic) and may be seen in some of their new vehicles. It's futuristic in the sense that it saves fuel. It saves all the fuel that would have been used, if the car was allowed to idle. Blue Efficiency and Bluemotion fuel technology doesn't allow the car's engine to idle, so when you start the car, it doesn't actually idle but the dashboard lights indicate that the engine has started. Logically there is no engine noise since there are no revs. The moment the car is engaged into gear and you remove your foot from the brake pedal, the engine starts instantly and pulls away as if it has been idling all the time. Exactly the same happens when coming to a compete stop at a traffic light or stop street. The engine switches off when the car comes to a halt, and remains off whiles you foot keeps the brake pedal depressed. However, the moment the pedal is released, the engine starts and the car moves off as if the engine was never switched off. There is no delay.

Having  said that, can you contemplate or just imagine the complexity of the electronics, both hardware and software employed in Bluemotion Technology, considering that many of the service agents are even stymied by the current German technology used in cars prior to 2008. The EPC on Volkswagen, Audi, Skoda, is just one of them. Central locking is another, ABS is a third and airbag a fourth. Intermittent reverse light whilst driving a fifth, brake light is on, blowing brake light fuses is a sixth and the list goes on. The repair and service charges for the non-Blue motion vehicles are already over the top so what can we expect to pay for repairs to Bluemotion technology vehicles. Besides who is going to repair them? Currently service agents are trowing spare parts at each electronic problem hoping that it would solve the problem but in most cases doesn't solve the problem.

Anyway, it appears that quite a few visitors who viewed my Electronic Power Control - EPC solution blog have no idea what a potentiometer (sender)  is, so let me explain and use the VW Polo accelerator pedal [accelerator position sensor (G79 & G185)] as a basis for understanding. Below is a picture of a potentiometer marked "A" that may be used in an electronic circuit. It specific one could be used as a volume control in an amplifier, or a sensitivity control on a disco strobe or a brightness control for a lamp dimmer. The uses for potentiometers are endless and has been used in cars for quite some time.

An overview of the  Electronic Power Control Circuit - EPC  in Volkswagen, Audi, Skoda.

The accelerator sender marked B and the throttle body housing marked C as seen above each have a gang potentiometer (meaning more than one potemtiometer in the same housing)  VW calls these both these potentiometers senders since they provide input to the ECU - Engine control Unit.  The ECU controls  the Drive-by-wire and any problems with it causes the car to go into "Limp Mode" resulting in the EPC warning light or other dashboard lights to come  on. Have a look at Electronic Power as to how the entire accelerator throttle  circuit is controlled and interfaces with the OBD2 /OBD II and Can Bus network.

ENGINE TROUBLE, CAR PROBLEMS

VOLKSWAGEN, POLO CLASSIC CAR PROBLEMS

This blog is about my 2007 VW Polo Classic 2.0L Highline and other VAG cars in general. I have always been fond of good, solid, precision German engineering and I stand firm in my conviction that my VW Polo facelift  fits the bill. It therefore makes me wonder what happened in the manufacturing process? I often ask myself, - Was my VW Polo manufactured on a Monday that I'm having so much car problems and have to visit auto repair so often?

With the amount of issues I've had with my VW Polo, it rather looks like it was manufactured on a public holiday. It makes no sense why I am having so much car problems with it. I have had a Mercedez Benz which was German engineered, I loved it. I also had an Opel Kadett GSI 1.8 with digital dashboard that was German engineered, I simply adored it.  I had three company cars all of which were German engineered VW Passats.  I've also owned two VW Golfs, both of which were German engineered. The first VW Golf was a 1100 Golf-1, the second was a 1600 VW Golf -2 CLI with large bumpers. All of which hardly needed  automotive repair. My VW Polo 2.0L Highline 2007 model is however is very different from all the VAG cars I have owned before.  For example, the electromechanical system of the VW Polo ascribes to the OBD-II standard as well as CAN-Bus and its certainly not the easiest VAG car to repair.

This Volkswagen  Polo has an on-board computer which interfaces with an ABS module, the Interior Electronics Module, the Engine Control Module, the  Immobilizer Control Module among so many, many other electronic modules. Ostensibly it could be said that each of these modules, is a computer in its own right and they are all daisy-chained on the same OBD2 / OBD II or CAN Bus network.

Auto repair :-

The above 16 Pin DIN J1962 socket is provided  for a diagnostic tester to interface with these Electronic Modules, and is the only way to communicate with the car. This socket is situated in various places on different models and makes of cars. For instance BMW's normally have them under bonnet in the engine compartment. Most Volkswagen's have this socket under the dashboard on the driver's side. Some cars have it in the glove compartment, some have it in and around the ashtray.

My VW Polo had an idling problem, it was idling around 1200 rpm which progressively increased and hovered about 2000 rpm. There is no adjustment because there is no accelerator cable / throttle cable - it has Drive-by-wire (DMW) also known as Electronic Throttle Control (ETC). It  is the latest automobile technology that replaces the conventional cable linkage system between the vehicle's accelerator pedal and the engine throttle body.

Anyway, the high rev drove me crazy, especially when changing gears, the revs just wouldn't come down or took forever to do so. After two days, the EPC light came on and I took my car  off to the agents who reset the throttle-body valve. It was fine for just two days until the the rev counter started hunting between 800 rpm and 1200 rpm and the EPC light came on again. I took the car back to the agents, only to be told that the throttle body was effectively faulty. The cost was equivalent to one monthly car installment and that excluded their labour charge. So I decided to get a second opinion  before I forked out so much money, since I don't have a motor plan.

My new auto mechanic plugged in his Auto Boss Automotive Scanner and a few minutes later he said its the accelerator pedal that was faulty or rather the sensors that control acceleration which is part of the accelerator pedal. I asked about the possibility of the accelerator throttle-body being faulty and he says "no ways,  who even thought that? Your car revs higher than 1200 RPM". He the asked "does your EPC light come on?" and I said "yes". He then leaned into the car, grabbed hold the accelerator pedal with his hand and pulled the accelerator pedal upward. Immediately the idling seemed right, or at least to me it sounded right because it was idling at 950 RPM. By demonstrating this, even the data that was missing from one of the cells on the diagnostic tester's display came back and flashed the word NORMAL. He then released the pedal, the revs once again increased and the data cell  on the diagnostic tester's display went blank once again. After replacing the accelerator pedal with the Drive-by-Wire potentiometer (G79 & G185 sensors) attached, the idling was perfect and the EPC light stayed off.

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