Economy / Shift Indicator on 1995 BMW 525i Auto

[Scott C]

Long story short,
After many repeated component changes, the instrument display that shows the current trans mode and gear selected (under check control) now occasionally fades away to a blank display. Turning the ignition off and restarting always brings this display back to normal. Any thoughts? This occurs with the engine running or not.

I should also mention that I get phantom TRANS PROG faults, but these are not recorded in any control unit. Have had the car at the dealer and used the Diagnostics - even with the TRANS PROG fault present on the CCM it does NOT show on the Transmission computer, the ECU or the instrument cluster.

Components changed or swapped - Transmission control unit, Check Control Module, Instrument board ($800), transmission switches cleaned and verified proper (using diagnostics). The Engine Control Unit has NOT been swapped - yet. Throttle position sensor passes all tests as well. Most grounds have been checked and look good (tightened). The 50A fuse near the battery is fine. The alternator is fine - voltage good with and without load.

I am at wits end....

Thanks,
Scott

[Scott C]

[QUOTE=Scott C]Long story short,
After many repeated component changes, the instrument display that shows the current trans mode and gear selected (under check control) now occasionally fades away to a blank display.


Since the BMW diagnostic tester actually induces the reporting of a trans prog fault (or can), I wonder if anybody has had a problem with the CAN communications network used internally by all of the black boxes for diagnostics? That seems to be the next area to look.

Thanks,
Scott