TIS Service Bulletin

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SI B12 31 18
Engine Electrical Systems

December 2018
Technical Service

ACTRON ACCUMULATED MISFIRE COUNTER
MODEL
All vehicles equipped with OBDII systems

SITUATION
In certain rare situations, intermittent drivability issues may not be severe enough to induce faults and require a
very specific conditions to be observed.

CAUSE
Limitations if the diagnostic systems

CORRECTION
To aid in these situations, the accumulated misfire function is now available as an expanded capability for the
Actron Scan tool. The Actron Scan tool (CP9670) was initially distributed through the automatic tool shipment
program (SI B04 18 15) and is now available in the aftermarket. This supplemental diagnostic tool may be
utilized in instances when no faults are stored and specific dynamic driving conditions are needed to reproduce
the complaint. The Accumulated Misfire function will provide a live aggregate count of misfires detected in each
cylinder. The misfire counter is incremented when the crankshaft speed fluctuates thus may occur when the
engine speed changes. The misfire counts will reset to zero after the key is cycled and the engine is started.
Note: Misfire counts may be present in normal engine operation and do not necessarily indicate a
fault. Further analysis and diagnostics will be needed to determine if the observed counts are caused by an
underlying issue.

PROCEDURE
1. Update the Actron scan tool with the procedure outlined in “Actron Misfire Detection Update
Procedure.pdf”.
2. Start the Accumulated Misfire function as described in the table below:



Connect to the vehicle

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

Complete the error code readout and emission system
monitor readout



Select Vehicle Diagnostics from the Main Menu



Select Accumulated Misfire from the Diagnostic Menu



Observe that some misfire counts may already be stored.

Note: This does not indicate a fault and is caused by changes in

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crankshaft speed during normal engine operation.



As the Misfire counts accrue, a bar graph will appear as a
visual aid.

Note: Depicted left, the most likely cause of the drivability
complaint only affects cylinder three.

3. Test drive the vehicle in a manor to induce the complaint
4. Evaluate the results and continue diagnostics

WARRANTY INFORMATION
Further information about the Actron Scan tool can be found in SI B04 18 15

ATTACHMENTS
View PDF attachment Actron Misfire Detection Update Procedure.
[ Copyright ©2018 BMW of North America, Inc. ]

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B12 31 18

Actron Accumulated Misfire Counter

December 2018

ACCUMULATED MISFIRE UPDATE PROCEDURE
1. Download the Actron Scanning Suite
from TIS by following the path below.
TIS/ Tools and Equipment / Workshop
Equipment column / Actron
Accumulated Misfire Update

2.

Once installed, run the application and
select Tool Update

3. Connect the Actron scan tool to the
computer via USB.
4. Select Automatic detection mode

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B12 31 18

Actron Accumulated Misfire Counter
December 2018
5. Set the Actron scanner to Program
Mode.
a. From the Main Menu
b. Select System Setup
c. Next select Program Mode
6. Select Next from the Scanning Suite
installation window

7. Select the 10/30/2018 Application
8. Press Next
Note: This application may need to be run
outside network as firewalls can interfere with
the update process

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B12 31 18

Actron Accumulated Misfire Counter
December 2018
9. Once the software download is
complete, select Next

10. Select Finish and the software will be
loaded into the Actron Scanner.
Important: Do not disconnect or interrupt this
process or the scanner may be damaged

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