Coolant hose connection diagram
Cars without independent heater
Blue = large coolant circuit. Red = small coolant circuit. Brown = heating circuit. Orange = EGR cooling circuit.
1. Not installed.
2. Coolant radiator: after replacement, change the coolant.
3. Coolant pump.
4. Cylinder head/cylinder block: after replacement, change the coolant.
5. Radiator system. eGR: Change the coolant after replacement.
6. System temperature sensor. exhaust gas recirculation "G98".
7. Coolant temperature sensor "G62".
8. Coolant circulation pump "V50": only for vehicles with start-stop system.
9. Coolant shut-off valve: Vacuum-pressure-controlled coolant shut-off valve for Climatronic "N422".
10. Ventilation hole.
11. Heater heat exchanger: after replacement, change the coolant.
12. Thermostat: radiator system. exhaust gas recirculation.
13. Check valve: the arrow indicates the direction of flow.
14. Expansion cover. coolant reservoir.
15. Expansion tank: check the system. cooling for leaks.
16. Oil radiator: after replacement, change the coolant.
17. Radiator pump system. exhaust gas recirculation "V400".
18. 4/2-way valve with thermostat.
Car with independent heater
1. Not installed.
2. Coolant radiator: after replacement, change the coolant.
3. Coolant pump.
4. Cylinder head/cylinder block: after replacement, change the coolant.
5. Radiator system. eGR: Change the coolant after replacement.
6. System temperature sensor. exhaust gas recirculation "G98".
7. Coolant temperature sensor "G62".
8. Autonomous heater: only for vehicles with start-stop system.
9. Ventilation hole.
10. Heater heat exchanger: after replacement, change the coolant.
11. Heater coolant shut-off valve "N279".
12. Thermostat, radiator system. exhaust gas recirculation.
13. Check valve: the arrow indicates the direction of flow.
14. Expansion cover. coolant reservoir.
15. Expansion tank: check the system. cooling for leaks.
16. Oil radiator: after replacement, change the coolant.
17. Radiator pump system. exhaust gas recirculation "V400".
18. 4/2-way valve with thermostat.