2001 4.4 transmission issues

[gpeterson]

I recently bought a 2001 E53 4.4 with known transmission issues. It will slip in 1st gear maybe 1 out of every 10 times I accelerate from a stop. If I back off the throttle it will usually catch and I can accelerate. Occasionally it goes into trans failsafe mode. I get EGS gear monitoring codes (31, 34, 35) and IKE: EGS signal line disturbed (8D). Here is what I've tried so far:

-Checked trans fluid level (using proper ZF procedure). PO says fluid & filter were recently changed as an attempt to fix the issue

-Checked voltage when running. PO replaced battery & alternator as an attempt to fix the issue

-Replaced instrument cluster (speedo needle was stuck on the old one)

-Unplugged trans valve body connector and gear position switch connector, inspected/cleaned contacts

-Unplugged DME & EGS, inspected/cleaned contacts.

-Cleaned MAF (although I haven't had any DME codes)

-Reset transmission adaptation using INPA

-Swapped in spare EGS module

-Pulled the 3 DSC fuses (since I heard bad DSC can disrupt the CAN bus). I have not yet tried unplugging the DSC module, will do that soon. INPA reports DSC clamp 15 voltage at around 12v. Seems odd. DSC has had code 5A (DSC: brief power interruption) twice.


Any thoughts? Could a transmission mechanical issue be so intermittent? When it isn't freaking out it shifts well. I'm thinking/hoping it is an electrical issue, especially with the 8D "IKE: EGS signal line disturbed" and the occasional 5A "DSC: brief power interruption".