A/T - Diagnosis And Troubleshooting Hints
SI B 24 23 07
Automatic Transmission
November 2009
Technical Service
This Service Information bulletin supersedes SI B24 23 07 dated February 2008.
[NEW] designates changes to this revision
SUBJECT
6-Speed Automatic Transmissions Diagnosis and Troubleshooting Hints
MODEL
All with ZF 6HP transmission
All with GM6 transmission
SITUATION
Diagnosing symptoms involving 6-speed automatic transmissions and determining the root causes of the complaints are the areas where specialized
assistance is often needed. Due to the high cost and complexity of the 6-speed automatic transmissions, an Enhanced Technical Support process has
been developed to help identify the root causes of customer complaints relating to Automatic Transmissions concerns.
All diagnostic and troubleshooting steps listed in this Service Bulletin should be performed prior to submitting a PuMA case ("TC Case" or regular
technical support "Case").
A PuMA case may be submitted ONLY after all appropriate diagnostic steps and/or hints listed below were performed and diagnostic results are
inconclusive (regular technical support case) or when a component replacement (transmission, Mechatronic, or VB-TECHM) is requested ("TC
Case"). Such a PuMA case must include all the necessary information required by B24 23 07.
IMPORTANT
Both "TC Cases" and regular technical support "Cases" will NOT be processed and will be rejected as "unjustified" if the basic diagnostic
troubleshooting procedures and corresponding information required by SI B24 23 07 are not performed and submitted.
PROCEDURE
When diagnosing the 6-speed automatic transmission complaints, the following troubleshooting steps should be performed, and required information
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needs to be included in a PuMA contact (both "TC Case" or a regular technical support case):
1. Customer Concern
^ Drive the vehicle to reproduce the customer's complaint.
^ Be as specific as possible when describing the issue at hand, including the exact driving and environmental conditions required to reproduce
the complaint. ("Transmission is shifting badly" will create more questions than answers).
^ If the complaint cannot be verified, contact the customer to obtain a specific description of the problem. If possible, test drive with the
customer, observing any unusual driving habits (e.g., "Two-footed driver").
2. FASTA Data
^ Perform a "Short Test" and transmit the FASTA data prior to programming or troubleshooting. In many instances, the "uncontaminated"
FASTA information may be helpful in determining the root cause.
3. Transmission Fluid Level/Fluid Condition
^ Check the fluid level for all transmission concerns, even if there are no obvious signs of external leakage.
^ Follow the appropriate fluid level checking procedures. The main items to remember are:
^ Check the level at fluid temperature between 30?to 50?C.
^ Engine running at idle.
^ Transmission in Park.
^ Vehicle leveled and secured against movements.
^ If the fluid does not flow out when the plug is removed, then add the appropriate amount until it trickles out. DO NOT insert your fingers into
the filler hole to check where the transmission fluid is!!!
^ Make sure that you are checking the fluid level at the correct filler (overflow) plug, since they have different locations. (On the E53 with
6HP26, the overflow plug is in the pan; on other applications, it is located on the side or at the rear of the transmission.)
4. Transmission Shift Concerns and Fluid Leaks
Adjust and/or correct the fluid level, and then clear the EGS adaptation values and test drive.
^ If the shift issue is resolved, then address the root cause of the leak.
^ If the complaint is unresolved, then submit a PuMA case for further instruction.
5. External Damage
^ Inspect the transmission oil pan for obvious signs of impact.
^ Inspect the external shift or emergency release cable adjustment, bracket and lever.
6. Transmission Fault Codes
[NEW] Diagnostic fault codes are an essential tool for troubleshooting. Print and secure the fault codes before clearing. Perform all applicable
ISTA (GT1) test plans as prompted by the EGS fault codes stored.
^ For the EDS (pressure regulators) and the MV (magnetic valves) fault codes, check the environmental conditions when the faults were set. In
general, electronic transmission control units work correctly when the voltage range is between 10V and 15V. If the fault codes
environmental conditions indicate voltage below 10V or above 15V, then troubleshoot vehicle's electrical system, e.g., the battery, battery
connections, grounds, charging system, the integrity of the vehicle's transmission harness and its connector (X85xx).
^ Prioritize the relevance of all driveability-related faults stored in the DME, DSC or EGS control modules. For example, if the vehicle ran out
of fuel and the engine stalled, the consecutive misfire and transmission gear monitoring faults (slippage faults) are irrelevant.Various engine
driveability complaints ("stumbling, poor running, hesitation") caused by poor fuel quality may also result in transmission shift quality
complaints.
7. Aftermarket Equipment
^ Inspect the vehicle for the presence of any aftermarket equipment (including wheels and tires), or software which may affect vehicle
performance or may cause customer concern.
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^ Mention any modifications to the vehicle (e.g., "Conversion to a stretch limo") in the submitted PuMA case.
8. Programming Replacement Transmissions and Mechatroniks/VB-TECHMs
^ Print the short and the long EGS ID page before removing the transmission or Mechatronik (VB-TECHM). You may need the part numbers
for the programming of the replacement unit. Refer to SI B24 18 07 (Programming of replacement Transmission or Mechatronic) for helpful
hints on EGS programming.
^ [NEW] On vehicles equipped with the GWS gear shifter, prior to transmission or Mechatronic replacement, perform the "EWS Reset
Function" using the ISTA path: "Service Functions/Transmission control/Calibrations/EWS Reset/Test plan".
9. Repair History
Check the repair history to see if there were any recent repairs that could affect the proper operation of the transmission. (If the vehicle returns
with a transmission slippage concern after an oil leak repair, chances are that the transmission fluid level is incorrect, causing a new driveability
complaint.)
10. SI Bulletins
^ Check to see if there are any Service Information Bulletins that apply to your specific complaint. Make sure that both "subject" content and
the affected vehicle model match your case.
^ Follow the SI B instructions exactly. (SI B24 14 07 states that the guibo needs to be removed for the inspection; a visual external inspection
will not be sufficient to reveal the loose bushings that we are checking it for.)
11. Vehicle VIN Number
^ Double check the VIN number before submitting a PuMA case. The incorrect VIN will prevent access to FASTA information. Also, the
requested IBAC programming codes will not work with an incorrect VIN.
12. Transmission Serial Number/Part Number
^ Always provide a transmission serial number and part number from the transmission's ID tag. The transmission serial number is an essential
piece of information needed by the Hotline Expert; it is especially useful on repeat complaints after a transmission replacement.
13. PuMA Reporter and Valid Phone Number
^ Preferably, the reporter listed in the PuMA case should also be the person who works on the vehicle. If it's not possible, mention your name
in the "Work performed" section of the case.
^ Always provide a direct and a valid phone number so that you can easily be contacted if necessary by the Transmission Expert.
[NEW] WARRANTY INFORMATION
TeileClearing is required for part replacement to be paid by BMW NA via Warranties: Limited New Vehicle Warranty, Certified Pre-Owned
Protection Plan, Federal and California Emission Control Warranty, Original Owner Protection Program and Extended Vehicle Protection Programs.
It is not required to submit a TeileClearing case for an out-of-warranty situation, i.e., BMW Center Administered Customer Assistance Program/Self
Authorization (Goodwill). When technical assistance is required to ensure "Fix It Right The First Time", please submit a regular technical support
"Case" and do not submit a "TC Case".
