Engine/Fuel - Lack Of Power, MIL ON And DTC P1688 Stored

SI M12 06 06
Engine Electrical Systems

November 2006
Technical Service

This Service Information bulletin supersedes S.M. M12 200 04 dated May 2004.

SUBJECT
W11 - DME FC P1688/Diagnostic Hints

MODEL
MINI Cooper S

SITUATION
Customer complains of lack of power and engine is in a failsafe mode. The "Service Engine Soon" light is illuminated and fault code P1688 ("Electronic throttle control monitor level 2/3; Mass air flow calculation") is stored in DME (EMS2000).

CAUSE
Possible failure of the supercharger bypass valve (sticking operation).

PROCEDURE
When performing a DIS/GT1 test module after fault P1688 is stored, in most cases the test plan incorrectly directs technician into replacement of the DME control module.

When diagnosing Cooper S with DME fault P1688, inspect the proper operation of the bypass valve in the air intake system. Using a handheld vacuum pump, activate bypass valve and observe its operation. If valve is sticking in any position, replace it with new part (PN 11 61 1 501 937).

WARRANTY INFORMATION
For information only.