BMW Rear Defroster on Permanently

People are saying, the right tool for the right job. Its apply for BMW repair to.  Correct?!

Late Model 435 GC BMW’s Battery is Flat Dead

One of our customer ran into a problem. His late model 435 GC BMW’s battery is flat dead. The car has been towed in.

The owner said it goes totally dead in a very short period of time. The car’s battery was 6 years old, it saw better times. Winter is comming and a 6 years old battery is old, this one is shorted and toasted. We replaced it.

A 6 Years Old Battery is a Old Battery

With new battery quickly check for excessive current draw. Tony found 15 amps steady draw at all the time, locked or not. When the ignition key is pulled out, it should go to sleep. But not so this one. Apparently something is draining the battery.

Preliminary checks done, no immediate clue which module cause the problem. Which one is acting out from the 50 or so onboard? Which one is staying on and “cooking” the battery in the process?

Failed Module. Which one?

Here comes the right tool that I mentioned in the first sentence.   Here comes Flir out to see what the human eye cannot see, which is thermal image.

Thermal Imaging To Diagnose BMW's Electrical ProblemFlir Thermal Imaging Read More on Our Facebook

Long behold the rear defroster staying on permanently.  Bingo, the module is staying on for good, she is locked on permanently as you can see on the above Flir image, it’s very colorful  from the heat emanating from the current flowing thru it.

Thermal Imaging To Diagnose BMW’s Electrical Problem

Case closed temporary,  we disabled the rear defroster until new module arrives. Client is happy, issue has been resolved, his BMW back on the road.

It is heard of: If the rear defroster on all the time, it can do more then kill the battery. If a defective defrosters heats the rear windshield all the time, it might explode, because the cold and hot combination. So it worth to keep your eye on it…

You can do several things if something like this happens with you, the first one, give us a call, and we will do the rest.

Call us for details: Telephone: 905.795.0419

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Battery Maintenance

Midtronics GR8-1200 Electrical System Tester


BMW starting & battery charging system

In our automobiles the battery is the one which provides the electricity to start the engine. Long time ago we could just jump start our car if the battery went weak or dead. All was well after, since the alternator kept all going just fine beyond the jump start. Today that is no longer the case.

Jump starting your modern car may have unexpected and costly consequences, some expensive electronics may become permanently damaged, costing serious downtime and money.

A modern, today’s hight tech automobile starting and charging system is as sophisticated as is the modern automobile itself. You may heard the phrase the “efficient dynamics” (BMW) and you may wonder what it means? Let us help you to understand a small part of it. The current management system as intended by BMW and Mercedes-Benz.

In the case of BMW it’s a combination of electronics working together commanded by the engine computer to optimize the charging and maintaining of the electronics in your BMW. The alternator will be turned on only when it’s required by the combination of battery voltage and the demand by the driver driving habits.

This has been developed to manage the starting capability of the engine and the optimization of the on board electronics at the least amount of drag generated by the alternator, while driven or if the vehicle is stationary. No demand has been registered by the ECU and the battery has been charged full, the alternator will freewheel until the demand goes up or the battery charge has been depleted far enough to have the alternator being turned on again.

 BMW 5 Series ECU BoxBMW 5 Series ECU Box

The engine ECU will also disconnect the alternator at full throttle to be able to exert maximum power from the engine as its demanded by the driver. This is all managed by a microchip embedded in the negative battery cable and reporting in real time to the engine computer (ECU), in the event of low state of charge in battery while stationery the, intelligent battery sensor, (IBS, BMW speak) will shut down all the power to try to preserve engine restart when needed. Clear sign is the clock showing blank information as there is no time registered.

Please note the IBS sensor is an essential part of the vehicle’s electrical system which reporting at all times when data can be recalled by the appropriate diagnostic software for evaluation if required. The data will be available including the amount of trips and the length of trips taken also being logged for future evaluation by the technician as long as the battery has not been disconnected when all the data will be erased in the ECU.

It’s very important NOT TO disconnect the battery even if the battery is depleted, because all the data will be lost if the battery cable has been removed. The battery must be registered in the engine ECU after replacement with the type and the capacity for the ECU to be able to use the right algorithm for the current management (battery charging protocol) which has to be programmed with the BMW software.

We hope this helps to understand the concept of the modern automobile charging and current electrical management system.

Happy motoring from your European auto technicians at Techmax.


To prevent breakdown and keep you on the road safely, we use Midtronincs GR8-1200 Electrical System Tester – Analyzer to check, test your automobile electrical system. Read more…

Original BMW Batteries BOSCH Batteries

Original or High Performance BOSCH S5,  BOSCH S6 Batteries for Your Fine BMW – Mercedes – Porsche.

Original or high performance Bosch batteries are available for your European import car. Original BMW Battery installed with warranty,  or BOSCH battery (the choice is yours).

BOSCH warranty include  60-month pro-rated warranty with a free replacement within 3 years from date of purchase. Some condition apply.

Plus, you’ll enjoy peace of mind because BOSCH batteries comes with North America wide roadside assistance, and with toll free 1.800 phone number.

Read more at next…. Original or High Performance BOSCH Batteries for Your Fine BMW – Mercedes – Porsche!

battery tester print out

Before you replace your European import car battery, book an appointment for your car’s electrical system testing.

To prevent breakdown and keep you on the road safely, we use Midtronincs GR8-1200 Electrical System Tester – Analyzer to check, test your automobile electrical system.

As you can see at left, the tester prints out the test result.

Advanced Electrical System Diagnostics Featuring Digital Signal Processing short form is DSP provides the ability to analyze the amplitude level and frequency of the ripple pattern for improved accuracy and identification of open or shorted diodes.

Midtronincs GR8 tests the starter current draw and Alternator current output, include DMM Function for Advanced Diagnostics

AC/DC Volts, Volts/Amps mode, Temperature, Ohm meter, AC/DC Amps, Scope mode, Diode test Patented Conductance Cable Drop Test.

Interactive test routines using dual cable sets for more effective analysis of voltage drop across ground circuit, starter system, alternator system, and generic system testing.

Midtronincs electrical sytem analizer in work

Midtronincs GR8-1200 in Work

Original or High Performance BOSCH Batteries for Your Fine BMW – Mercedes – Porsche!

Call us for more details at  905.795.0419