E38 ECM and cruise control
Thread Starter
Teching In
Joined: Jul 2021
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E38 ECM and cruise control I’m doing a BMW E90 swap with a Gen IV and E38 ECM. The BMW has a cruise control module (a physical box under the dash) but I’m curious whether the E38 also manages cruise control within the ECM? For example if I were to sniff the CAN bus and translate the BMW codes for the cruise control buttons on the steering wheel into their corresponding equivalents on the GM side (eg with an Arduino board), would the E38 completely handle my cruise control (could I delete the BMW unit) or is cruise control managed by something else on the GM side? I’m hoping I can delete the BMW unit, because mapping some button codes sounds a lot easier than managing/translating BMW high-frequency, realtime accelerator pedal messages into E38 messages. It would also mean I can wire the accelerator directly to the E38 (or use the GM pedal), and nothing on the BMW side should need that information. I’ve read some posts where people advise bringing over the GM BCM for cruise, but I’m hoping thats just to avoid CAN bridge/translation (which I have to do anyway for other reasons).
Thread Starter
Teching In
Joined: Jul 2021
Posts: 9
Likes: 2
Their products seem like a good way to go around the oem systems (BMW in my case). I’m working to directly interface the two via a high speed CAN bridge/translator for a number of functions, so that the LS appears to be native-built. That’s why I want to learn what, exactly, in the Chevy is managing the cruise control—the E38 or something else?
TECH Resident
Joined: Apr 2008
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From: Right here, right now!
The E38 doesnt have enough pins for cruise control, so normally managed from the GM BCM via CAN. Unfortunately.
E67 can has enough pins and some models can do direct E67 based cruise.
E67 can has enough pins and some models can do direct E67 based cruise.
Thanks for pointing that out. It looks like their CRC-2000 might work for my setup (E38 with the DBW pedal and a separate VSS from my Magnum-F). I still drive 158mph at all times with my E38 expecting a CANbus signal from a non-existent TCM.
https://www.dakotadigital.com/index....od/prd1004.htm
https://www.dakotadigital.com/index....od/prd1004.htm
I use a Dakota Digital cruise -- works with my factory-looking Rostra (who makes DD's cruise) stalk on the column and magnets on the driveshaft for a speed signal. LS3/E38/DBW. Flawless OEM-level cruise function.
