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Old 12-05-2012, 03:13 PM
bimmerfan52 bimmerfan52 is offline
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Location: Arizona
Join Date: Feb 2012
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Mein Auto: 545i
Originally Posted by jpmlpt View Post
Wondering if anyone has seen this problem and possible solution:
Car starts from cold fine. 10 minutes into the drive, Transmission Failsafe Error appears.
Turning car on and off within 1 - 2 hours does not remove error.
Turned car off for 4 - 8 hours and the problem disappears, however, 10 minutes into the drive, the Transmission Failsafe Error reappears.
Dealer wants to replace transmission, but not convinced this is some unrelated electrical isssue.
You don't mention any transmission related issues such as slamming during gear changes, so I assume the transmission seems fine other than the warning light. Can you read a code to get more specific?

I agree it could be electrical, and you need to monitor your battery and alternator voltage real time. If the cause is electrical and it comes and goes it is very likely battery or alternator related.

Buy a cigarette lighter socket voltmeter (about $20), to monitor battery voltage before starting and during operation.

Another possibility is sticky solenoids in the valve body, but address the electrical system first.
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