Engine Controls - M271.8 EVO Engine Lacks Acceleration/Power

M271.8 EVO engine has poor accelerator response - lack of power under full load and high rpm

Topic number LI47.00-P-054771

Version 1

Design group 47.00 General

Date 10-26-2012

Validity MODEL 172; 204; 207; 212 with M271.8 EVO

Supersedes LI07.70-P-053794

Reason for change

Complaint:

Complaint of:

a) engine has poor accelerator response at take off (driving off)

and /or

b) engine has lack of power under a full load and high rpm

Engine diagnosis warning lamp (CEL) lights up, vehicle is in limp-home mode (may or may not be intermittent). Vehicle may return to normal operating condition after a key cycle.

Fault code - DTC P008A21 "The pressure in the fuel low-pressure system is too low".

The DTC P008A21 is the primary code. Other codes might be present in a short test.

Cause:

a) engine software / throttle mapping

b) in certain driving situations (primarily at high loads and high rpms), the engine control module software might erroneously detected an insufficient fuel pressure in the low pressure system, although there is adequate pressure present.

Remedy:

Refer to a and b for remedy however, check the fuel system first. Process the DTC P008A21 and any other codes that might be present in SDS.

If there is no apparent issue with the fuel system and results of guided tests are inconclusive then...

a) update ME

b) this occurrence can be identified by checking the fault freeze frame data. If the value for the low fuel pressure was recorded as being above 4 bar, the triggering of the fault code and CEL was most likely implausible.

Update the ME control module with below provided AddOns for the complaint described above:

AddOn 2519 Xentry version 07/2012

or

AddOn 2520 Xentry version 09/2012

Note:
This LI supersedes the LI07.70-P-053794.





Symptoms





Control unit/fault code