Emissions - MIL ON, Multiple DTC's Stored
SI B 12 04 00Engine Electrical Systems
November 2002
Service Engineering
This Service Information bulletin supersedes S.I. 12 04 00 dated July 2000.
[NEW] designates changes to this revision
SUBJECT
Secondary Air System Faults
MODEL
[NEW] All models with M52, M54, S52 and S54 engine
All models with M44 engine produced as of 1/97
[NEW] All models with M60 (3.0 liter) engine produced as of 10/94, M62 engine produced as of 9/98
[NEW] All models with S62 engine
[NEW] All models with M73 engine
SITUATION
Customer complains that the "Check Engine" lamp is illuminated and the following fault is set in the Engine Control Module (ECM/DME):
[NEW] M52, M54, S52, and S54 engine:
Fault code 245 (F5 hex) - Secondary air injection, bank 1
Fault code 246 (F6 hex) - Secondary air injection, bank 2
[NEW] M60, M62 and S62 engine
Fault code 80 - Secondary air injection, bank 1
Fault code 81 - Secondary air injection, bank 2
M44 and M73 engine:
Fault code 80 - Secondary air injection system
CAUSE
Failure within the secondary air injection system.
PROCEDURE
The following diagnostic tips / steps should be followed if the above customer complaint is received:
1. For E36 vehicles equipped with M52 engine prod. 10/95 - 2/96 also refer to SI 12 04 96 regarding Recall Campaign No. 96E-A01.
2. Refer to the OBD II training manual for illustrations and explanation of system operation.
3. Perform test modules/component activation of secondary air system located in the "Service Functions" section using DISplus/GT1.
4. Check operation of secondary air pump using instructions provided in DISplus/GT1.
5. If pump is not operating correctly check air pump relay. For vehicles with M52 engine a modified relay was introduced into production P/N 12 63 1 742 690.
6. If the relay is operating correctly and the electrical connections/wiring to the pump are OK, check the condition of the pump.
7. If the air pump is seized it must be replaced.
Important note:
If the pump is seized as a result of moisture (water in pump), an improperly operating non-return valve is the cause. The non-return valve may stick open and allow exhaust gases to condense within the air pump housing leading to a failure of the pump.
Non-return valve sealing / leakage check:
The non-return valve must be checked as follows any time a seized secondary air pump has been replaced due to moisture.
Disconnect the air pump feed line/hose (1) at the non-return valve (line from the secondary air pump to the non-return valve).
Visually inspect the non-return valve fitting internally for carbon type contamination. (Twisting the corner of a clean shop rag into the valve fitting as shown will assist with this check.)
If no carbon type deposits are found on the rag, this indicates that the non-return valve is sealing correctly and does not need to be replaced.
If carbon type deposits are found on the rag, the non-return valve is not sealing correctly and must be replaced.
Note:
A non-return valve which is not sealing correctly will cause damage to the secondary air pump as described above.
8. Check also for cracked vacuum lines going to the non-return valve.
^ For vehicles with M44 engine the vacuum line P/N 11 73 7 501 180 going to the non-return valve has been improved since 11/98.
^ For E46 323i/iA and 328i/iA vehicles produced 4/98 - 7/98 see S.I. number 12 04 98 regarding the vacuum hose to the secondary air non return valve service action.
PARTS INFORMATION
Improved Non-Return valves have been phased into production on all models.
A Non-return valve with a dated code stamping as of 99T075 (arrow) and later is the improved version. date cose explanation: 99=year, T=day, 075=75th day of the year.
Only the improved non-return valves are available from the Parts Distribution Centers.
WARRANTY INFORMATION