Engine - MIL ON/Codes 4521/4530 Diagnostic Info.

SI B 12 10 09
Engine Electrical Systems

February 2009
Technical Service

SUBJECT
E90, E70 M57Y Diesel - Diagnosis for DDE FC 4521/4530

MODEL
E70, E90 with M57Y engine

SITUATION

The Service Engine Soon lamp is illuminated (with a "Reduced Engine Power" message displayed in the CC), and one of the following fault codes may be stored in the DDE control module:

^ 4521 - Charge air pressure control, control deviation, charge-air pressure too high

^ 4530 - Charge air pressure control, control deviation, charge-air pressure too low.

CORRECTION

The possible causes for the induction undercharge/overcharge faults are:

^ Charged air leakage between the turbochargers and the intake manifold;

^ Air filter or air path before turbocharger clogged;

^ Incorrect operation of turbochargers actuators (low vacuum supply for wastegates, compressor bypass valve jammed, etc.);

^ Intake manifold pressure sensor malfunction;

^ Excessive backpressure in the exhaust system.

IMPORTANT:
Do NOT perform the ISID test module B1365_D7LMS (Air Mass System Test) which is called for the faults 4521/4530. The test module, in its current version, is not applicable for the M57Y US engine version and may produce implausible results, leading to unnecessary component replacement. Test module B1365_D7LMS will be corrected with future releases of ISTA/D.

In case fault codes 4521 or 4530 are stored, perform the following test modules:

^ B1362_D6TRK (Turbine control flap - wastegate control of the smaller turbocharger);

^ B1362_ D6WGV (Turbine control flap - wastegate control of the larger turbocharger);

^ B1362_D6VBK (Multistage turbo charging - US diesel).

To check the integrity of the intake system, perform the smoke test, using BMW approved smoke generating equipment (VACUTECreg; Smoke Machine 625-522B-BMW).

Refer to SI B16 01 07 for detailed information related to the VACUTECreg; Smoke Machine 625-522BBMW.

WARRANTY INFORMATION
For information only