Safety Precautions
Note the following when working on the fuel system:
There is a risk of injury because the fuel is under pressure.
- Place clean rags around the connection before opening the system. Then release pressure by carefully loosening the connection.
- Wear protective gloves.
- Wear safety glasses.
Very hot fuel can burn your skin.
- The temperature of the fuel lines and fuel may reach 100 °C (212 °F) after stopping the engine. Let the fuel cool down before opening any line connections otherwise there is a danger of scalding.
- Wear protective gloves.
- Wear safety glasses.
To prevent personal injury and damage to the injection and pre-glow system, observe the following:
- The ignition must be switched off before connecting or disconnecting injection and preglow system wiring or tester cables.
- Only clean engine with ignition switched off.
- If electrical connectors were disconnected and the engine was started, then malfunctions have been stored in the engine control module. "Check the DTC memory" in "OBD" => .
Danger of causing damage to electrical components when disconnecting the battery.
- Complete the steps for disconnecting the battery.
- Turn off the ignition and disconnect the battery.
-- Disconnect the battery. Refer to the appropriate service information .
Observe the following when working on the reducing agent metering system:
The reducing agent can cause skin irritation.
- Avoid contact with skin and eyes! Wear protective gloves!
- If reducing agent should get on your skin, wash it off immediately with soap and water.
- If reducing agent gets in your eye, rinse the eye for several minutes with water.
- Never inhale or swallow the reducing agent!
- Should you swallow any reducing agent, rinse your mouth, drink plenty of water and contact a doctor immediately.
Note the following when removing or installing any components of the reducing agent metering system:
- The reducing agent active/passive tanks must be empty when working on the reducing agent metering system. Be sure to read the work procedure whenever the reducing agent in the active or passive tank must be emptied. Drain the active tank or the passive tank, if necessary. For information on the active tank, refer to ADBLUE® ACTIVE TANK, DRAINING and for the passive tank, refer to ADBLUE® PASSIVE TANK, DRAINING .
Note the following when removing and installing the active or passive tank:
- The reducing agent active/passive tank must be empty. Drain the active or passive tank, if necessary. For information on the active tank, refer to ADBLUE® ACTIVE TANK, DRAINING and for the passive tank, refer to ADBLUE® PASSIVE TANK, DRAINING .
AdBlue®, Automatic Regenerating
- After switching off the ignition, any reducing agent is recirculated from the reducing agent injector -N474- metering line back into the active tank.
- Before working in this area, wait 10 minutes after switching off the ignition so that the recirculation can complete.
- Likewise, wait 10 minutes after switching off the ignition before disconnecting the battery so that the recirculation process can complete. Refer to the appropriate service information .
Danger due to reducing agent leaking out.
- To prevent large amounts of reducing agent when opening the metering line, wait for the recirculation process to complete SAFETY PRECAUTIONS .
Note the following when working on the cooling system:
Risk of scalding due to hot steam and hot coolant.
- The coolant system is under pressure when the engine is warm.
- Cover the coolant reservoir cap with a cloth and then open it slowly to release the pressure in the system.
When working on a vehicle with the Start/Stop System, note the following:
Danger of serious personal injury if the engine starts automatically on vehicles with the start/stop system.
- If the start/stop system is activated (message in the instrument cluster), the engine can start automatically.
- Make sure the start/stop system is deactivated whenever working on the vehicle. Switch off the ignition and switch it on only when necessary.
If it is necessary to use testing and measuring devices on road tests, observe the following:
Distraction and improperly secured test equipment can lead to accidents.
There is a risk that the passenger airbag could deploy in a collision.
- Operating testing and measuring equipment while driving creates a distraction.
- There is an increased risk of injury due to unsecured testing and measuring equipment.
- Always secure testers on the rear seat with a strap and have a second person on the rear seat operate them.
Note the following when working on the exhaust system:
Danger of damaging the decoupling element.
- Decoupling element must not be bent more than 10°.
- Do not load decoupling element on cable.
- Do not damage wire mesh at decoupling element.