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.
Les McMaster, chairman 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 actuator s 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. McMaster 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,”
McMaster concludes.