Service Precautions

When servicing C220, the following precautions must be followed when using Hand-Held Tester (HHT):

• DO NOT  connect or disconnect Hand-Held Tester (HHT) to vehicle with ignition on. Voltage is supplied to HHT through data link connector.
• ALWAYS connect multiplexer cable to HHT first, then to data link connector.
• DO NOT  connect HHT to 110-volt or 220-volt power source.
• Keep HHT away from strong magnetic fields, such as welding equipment.
• DO NOT  expose HHT to water, brake fluid, thinners, etc.