Beware incorrect jumpstarting can damage your car’s computer

When an Electronic Control Unit (ECU) – also known as the ‘computer’ – of a vehicle needs to be repaired or replaced, motorists are often confronted with a hefty repair bill. This makes sense as an ECU is a very powerful control system capable of gathering hundreds of channels of information to control every aspect of your car’s engine management or other important vehicle functions such as handling characteristics, braking systems and climate control.

Pieter Niemand, Director of the Motor Industry Workshop Association (MIWA), explains how if one were to compare a car engine to a human body, the pistons might be the heart, the headlights would be the eyes, and the ECU would be the brain. The ECU controls a series of actuators to make sure things are running smoothly within the engine. Within the engine bay, there are several sensors that provide the ECU with maintenance information. The ECU then uses these sensor readings to adjust engine actuators for optimum efficiency.

“What motorists might not know is that they can contribute to the premature failure of ECUs by being unaware of the damage caused by not adhering to a couple of simple rules. Jumpstarting your car incorrectly is one of the most common ways one can damage an ECU,” he points out.

Niemand provides the following useful hints to help motorists extend the ECUs life’s expectancy:

· Be very aware of the polarity of the jumper leads when jumpstarting a vehicle with a flat battery as many an ECU has been damaged by short circuiting the jumper leads. Always connect the leads positive to positive and negative to negative and although most vehicle manufacturers have equipped their vehicles with overvoltage protector devices, damage may still happen in the split second before the fuse in the system blows.

· Always connect the positive leads of both batteries first, then the negative leads. This will “soften” the flow of power through the earthing system and prevent power surges or spikes.

· Never attempt to connect the jump leads with the key in the ignition, only insert the key once the leads have been connected. Failure to adhere to this may lead to the coding between the key and the ECU becoming corrupted and in many instances this corruption is irreversible.

“If you are in doubt on how to jump start your vehicle, seek the advice of your nearest MIWA accredited workshop in your area who will be happy to explain the proper jump starting procedures to you,” Niemand concludes.