Cooling System - Various Driveability Concerns/DTC 2EFE
SI B24 02 08Automatic Transmissions
September 2008
Technical Service
This Service Information bulletin supersedes SI B24 02 08 dated February 2008.
Similar information may be found in SI B12 09 08 dated September 2008.
[NEW] designates changes to this revision
SUBJECT
Driveability Complaints due to Cooling Fan Relay Failure
MODEL
[NEW] E60, E61 with N54 engine produced from 03/07 up to 07/07
E70 with N52K or N62TU engine produced from 04/07 up to 07/07
SITUATION
The customer may complain of intermittent driveability problems, described as:
^ "The engine is lacking power when accelerating uphill"; or
^ "The transmission will not upshift under heavy acceleration"; or
^ "Distinct hesitation when accelerating from 30-45 mph".
During diagnosis, fault code 2EFE "Electric cooling fan, activation" is stored in the DME, but currently is not present.
The customer may also complain that the yellow temperature warning light intermittently illuminates in the instrument cluster (with warning message displayed in the Control Display) and the air conditioning system malfunctions intermittently.
CAUSE
The engine has entered a "power reduction mode" due to intermittent failure of the power supply relay of the electric cooling fan.
Information:
With the introduction of the "new generation" family of engines, beginning with E65 vehicles (except N73 engines), the following cooling management and/or engine protection strategy has been implemented:
^ Coolant temperature exceeds 117°C Engine enters the "power reduction mode". There are no warning displays in instrument cluster or Control Display and no fault codes are stored in the DME indicating limited engine output. Individual faults related to failures of certain components of the cooling system (e.g. cooling fan, thermostat, electric water pump, etc.) may be stored in the DME.
^ Coolant temperature exceeds 120°C Engine in the "power reduction mode". A yellow warning ("radiator icon") is displayed in the instrument cluster. An audible gong is activated and a message "Engine too hot, drive with moderation" appears in the Control Display. Individual faults related to failures of certain components of the cooling system (e.g. cooling fan, thermostat, electric water pump, etc.) may be stored in the DME.
^ Coolant temperature reaches 125�C Engine in the "power reduction mode". A red warning ("radiator icon") is displayed in the instrument cluster. An audible gong is activated and a message "Engine overheated, stop vehicle carefully" appears in the Control Display. Individual faults related to failures of certain components of the cooling system (e.g. cooling fan, thermostat, electric water pump, etc.) may be stored in the DME.
CORRECTION
On a customer complaint basis only, perform diagnosis with DIS/GT1 and work through the corresponding test modules. Additional diagnostic hints can be found in SI B17 02 07 ("E70, E60 - Diagnostic of Electric Cooling Fan" from 09/2008).
In case the root cause of the problem can not determined during the diagnostic process (fault is currently not present and could not be duplicated), then replace the power supply relay K9137 for electric cooling fan (PN 61 36 7 661 503).
PARTS INFORMATION
WARRANTY INFORMATION
Covered under the terms of the BMW New Vehicle Limited Warranty.
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