Engine - Diagnosis Plan Updates
SI B 12 29 05Engine Electrical Systems
December 2005
Technical Service
SUBJECT
S85 Engine Diagnosis Test Plan Updates
MODEL
E60 M5
INFORMATION
This bulletin provides diagnostic tips for using the following Test Plans to diagnose engine related drivability complaints.
^ Combustion Quality Test
^ Duration Of Spark Test
^ Compression Test
Combustion Quality Test:
The Combustion Quality Test replaces the smooth running test. The Combustion Quality Test has an operating range of 0-5, when no combustion takes place the value will decrease to 0.0. A properly operating vehicle will indicate a value of 1.2 to 3.0 for each cylinder.
The Test Plan can be found using the following path:
Function Selection - Complete Vehicle - Motor Electronics - Misfire Detection - Test Plan
Duration Of Spark Test:
The duration of spark is measured after the ignition spark has been triggered, this measured value is indicated in milliseconds and the operating range is between 0.1 and 1.5. If the ignition fails, the value will decrease to 0.1ms. A properly operating vehicle will indicate a value of 0.5 to 0.75 for each cylinder.
The Test Plan can be found using the following path:
Function Selection - Complete Vehicle - Motor Electronics - Misfire Detection - Test Plan
Compression Test:
Currently a Compression Test Plan is not available via the diagnostic software or the TIS Repair Instructions. A new procedure is currently being developed. Until this procedure is released please utilize the temporary procedure described below. In the interim until a special tool is developed, a Snap-On(R) compression tester can be used. With the introduction of the S85 engine, BMW now utilizes a 12 mm spark plug unlike the previously used 14 mm spark plug, Snap-On(R) provides PN EEPV306A screw in test probe to accomplish this test~
1. Remove Fuel Injection Relay K6326 (next to the black 5 fuse holder) Located in the E-Box, start vehicle to clear excess fuel from the plenum, the vehicle should start and stall immediately.
2. Remove the plastic covers from both valve covers to access the ignition coils, the upper halves of both air box's will need to be removed to accomplish this.
3. Remove both covers for Ionic Current Control Modules, with ignition off remove the electrical connectors for these control modules (both banks). This will disable the ignition system.
4. Remove the coils and the spark plugs; proceed with the Snap-On gauge as described above. Apply a drop of oil to the probe threads to resist going of the dissimilar metals.
5. Connect vehicle to DIS plus or GT1, go to Control Unit Functions, Motor Electronics, Activate Components and select Throttle Valves 1 or 2 depending on bank to be checked. When selecting the component the throttle valve will stay activated (open) for approximately 30 seconds, during this time a compression test can be achieved. The throttle valves will need to be activated for each cylinder until the compression test has been completed.
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