Auto box- Jerky shift from park when cold + yellow cog light

[BMmad]

Hi all,

I’m hoping someone here can shed some light on a strange issue I’m having with my 2003 Z4 2.5i (M54, automatic, around [insert mileage] miles).

When the car is cold — usually first start of the day — and I shift out of Park into Drive or Reverse, the whole car jerks/lunges quite aggressively. It feels like a sudden clutch engagement or drivetrain shock. Alongside this, the yellow cog warning light appears on the dash (transmission fault warning).

Oddly enough, once the engine warms up (after a few minutes), the issue seems to go away. Shifts are smooth and the warning light stays off for the rest of the drive.

What I’ve noticed:
•Only happens when the engine is cold.
•Light goes away after restarting or warming up.
•No strange noises from the gearbox itself.
•Fluid condition and level are unknown (yet to be checked).

I’ve heard the EGS (transmission control module) can throw faults like this, and some mention early signs of torque converter or solenoid issues. But I’d love to hear if anyone else has experienced this or has suggestions on what to check first.

Any advice would be appreciated!

Cheers,

 

[Rockhopper]

Classic position switch failure symptoms.

 

[BMmad]

Thanks Rockhopper , I’ve read lots of advice having found it to be a common problem from owners on here who have had similar issues

 

[Z44Jon]

100% what mine was doing, new gearbox switch required.

 

[Limpet]

Probably worth a fluid and filter change as well if you're unsure when it was last done. Never understood this lifetime fill nonsense that BMW (and others) peddle. ZF recommend 60-80k (miles) changes on most of their transmissions. If the fluid deteriorates to a point where it causes issues or noise, it's too late by then.