1998 BMW 318 Transmission slamming/error

ENGINEER-PILOT

MEMBER
1998 BMW 318
4 CYL
2WD
AUTOMATIC
165,000 MILES

At low speed on breaking, the automatic transmission is recently slamming into a low gear and instantly settling back into a normal drive mode. After this happens, the transmission warning light alights along with the ACM light. The lights reset when the car is restarted. After this happens, upon normal highway driving at constant speed, I notice that there is a minor grabbing type feel of the transmission that seems to cycle on and off.

A review of previous transmission questions appears to indicate that there could is a bad chip in the Transmission Control Module.

1. Does this sound reasonable?
2. Where is the TCM?
3. Can the chip just be replaced, or does the entire TCM need to be replaced?
4. Upon replacement of the TCM or chip, does it need programming or can I just get up and go?

1 Reply

DOCHAGERTY

MECHANIC
9,601 POSTS

I acknowledge your ability to research, most dont bother, thank you. The EGS in a 1998 does have a chip and it is just above the glovebox and it is accessible only from the engine bay. It is plug and play. The numbers on the EGS will determine the chip part number.