Remove/Install Heater Unit - AR83.70-P-5302GW

Model 463 

as of model year 2013 up to model year 2019 

with code H12 (Auxiliary heater) 

/Facelift 2012 

Fig 1: Heater Unit Components Location - Model 463 As Of Model Year 2013 Up To Model Year 2019 With Code H12

Courtesy of MERCEDES-BENZ USA

Shown on engine 157 

Courtesy of MERCEDES-BENZ USA

	Remove/install
	Risk of injury  to skin and eyes suffering scalding from contact with hot coolantspray. Risk of poisoning  from swallowing coolant.	Do not open cooling system unless coolant temperature is below 90 °C. Open cap slowly and release the pressure. Do not pour coolant into beverage containers. Wear protective gloves, protective clothing and safety glasses.	AS20.00-Z-0001-01A
	Notes on coolant		AH20.00-N-2080-01A
1	Release pressure in coolant circuit	To do so, unscrew cap of coolant expansion reservoir.
2	Clamp off coolant hoses (1)	Clamp	Fig 2
3	Loosen clamps (2) and remove coolant hoses	Collect escaping coolant in a suitable vessel.
4	Unclip electric line (3) from stationary heater unit (A6)
5	Remove front left wheel well trim
6	Detach air intake hose (4) from air intake line (7)
7	Remove screw/bolt (5)
8	Open clamp (6) and detach air intake line (7)
9	Unscrew nuts (8)
10	Unscrew nuts (9) and slightly press power steering expansion reservoir (10) forward
11	Disconnect electrical connectors (11)
12	Detach air intake line (12) from stationary heater unit (A6)
13	Open hose clamp and detach exhaust gas line (13) from stationary heater unit (A6)
	Risk of explosion  caused by fuel vapors igniting, risk of poisoning  caused by inhaling combustible gases and risk of injury  caused by burns during and after operation of heater unit	Do not operate stationary heater, auxiliary heater or engine with heater booster in closed rooms or when refueling. Allow heater unit to cool down after operation and wear protective gloves.	AS83.70-Z-0002-01A
14	Detach fuel line (14) from stationary heater unit (A6)	Collect escaping fuel in a suitable vessel.
15	Remove stationary heater unit (A6)
16	Install in the reverse order
17	Bleed coolant circuit after installation of stationary heater unit (A6)		AR83.70-P-5302-01GW
18	Commission stationary heater unit (A6)
		If the stationary heater unit (A6) switches off automatically before reaching its operating temperature and cannot be restarted, then there is a fault interlock: ↓ Rectify fault interlock with Star Diagnosis, control units actuation. ↓	AD00.00-P-2000-04A

Fig 2: Identifying Clamp (000 589 54 37 00)

Courtesy of MERCEDES-BENZ USA