Safety of the OBD Control Unit
The control units require that the ignition be switched off before connecting (or disconnecting) the battery. This prevents the occurrence of an undefined memory status in the control unit and partial or complete loss of data. In the event of this occurring inadvertently, the trouble codes are displayed and reprogramming is recommended.
Mains Voltages
As in motor vehicle electrical systems, dangerous voltages occur in the mains supply. There is a danger of electric shock through arc-over due to damaged insulation (e.g. animal bite damage to ignition leads) when touching components which are connected to a voltage supply (e.g. ignition coil). This applies to the secondary and primary side of the ignition system, the wiring harness with plug connections, lighting systems as well as tester connections.
Never disconnect or re-connect wiring harness plugs from/to control units or trigger boxes with the ignition switched on.
During operations on the fuel system, keep sources of ignition away and avoid generating sparks.
Danger of Acid Burns
When measuring exhaust emissions, the hoses employed for sampling release a highly corrosive gas (hydrogen fluoride) if heated above 250 °C or in the case of a fire. These can cause acid burns to the respiratory organs.
The condensate, which collects in the sampling hose and in the condensate receptacle is also acidic.
When replacing the O 2 measured value sensor, it must be noted that the sensor contains an alkaline solution.
If liquid crystal fluid escapes when a liquid crystal display is damaged, the liquid must under no circumstances be allowed to come into direct contact with the skin, be breathed in or swallowed.
Danger of Suffocation
Motor vehicle exhaust emissions contain carbon monoxide (CO), a colourless and odourless gas. When breathed in, carbon monoxide leads to oxygen deficiency in the body. Particular caution is necessary when working in pits as some exhaust gas constituents are heavier than air and settle at the bottom of the pit.
Danger of Injury, Danger of Pinching
In cases of vehicles not being secured against rolling, there is a danger of being crushed against a workbench. In running engines, but also in engines at standstill, there are rotating and moving parts (e.g. belt drive), which can lead to injuries to fingers and arms. Particularly with electrically driven fans, there is a danger that the fan can switch on unexpectedly when the engine is at standstill and the ignition switched off.
Danger of Burns
When working on hot engines, there is a danger of burns if components such as exhaust manifold, turbocharger, oxygen sensor etc. are touched or approached too closely. Depending on the duration of the exhaust emission measurement, the sampling sensor of the exhaust gas measuring instrument may become very hot.
Danger of Fire, Danger of Explosion
When working on the fuel system/mixture preparation there is a danger of fire and explosion due to fuel vapours.
Leaking fuel must be mopped up immediately.
Noise
When measurements are made on the vehicle, noise levels above 70 dB(A) can arise, particularly at high engine speeds. Damage may be caused to hearing in people subjected to noise levels of this magnitude over a long time period.