Reduced Heat After Cooling System Repairs (17 01 15)

Publication date: 2015-02-01
Reference number: 17 01 15

REDUCED HEAT AFTER COOLING SYSTEM REPAIRS

TECHNICAL SERVICE BULLETIN

Reference Number(s): SI B17 01 15, Date of Issue: February 2015

BMW:	F30 (3 Series Sedan); Produced to 7/2014; With the N55 engine and option 0337 (M Sport Package)
GROUP:	Cooling Systems

SUBJECT

Reduced Heat After Cooling System Repairs

SITUATION

The customer may complain of low or no heat output at lower outside temperatures. Fault Code 1D2008 "Map thermostat: jammed open" may be stored in the DME.

CAUSE

The coolant hoses for the external engine oil cooler are routed incorrectly. These hoses have the same fittings and can be interchanged by accident when the cooling system is opened during repairs.

PROCEDURE

There are three hoses in the engine oil cooling system at the right side of the radiator (1).

NOTE: (The harness for the auxiliary fan has been removed for clarity.)

The top hose with the bleed screw (1) is attached to the cooler for the engine oil, and connects to the engine's cooling circuit. The middle hose (2) comes from the cooler and connects to the remote engine oil heat exchanger. The bottom hose (3), with bleeder fitting, connects the engine oil cooler coolant pump to the auxiliary radiator in the wheel well.

The fittings for the hoses (2) and (3) are the same, and the hoses could be mistakenly switched. This would cause an additional coolant to be pumped directly into the engine's cooling circuit, preventing the engine from reaching the operating temperature. If the hoses need to be switched, the cooling system has to be vented and bled properly (Repair Instruction RA17 00 039, "Venting and filling cooling system with vacuum filling unit").

Refer to SI B 12 33 14 in case the hoses are installed in correct positions, and the vehicle has the same symptoms.

WARRANTY INFORMATION

Not applicable.