Trans won't shift out of first/Chevrolet Performance E67 Crate Engine PCM VSS signal

[cda951]

Hello, I am working on a customer's 2001 BMW 740iL with the GMPP E67 ERod LS3 crate engine and 4L60E transmission with the GMPP "Connect and Cruise TC-2" transmission controller and harness. The vehicle drove and shifted normally when I first tried it months ago, but since installing HP Tuners and changing the ECM-controlled fan setting and tachometer output settings using a patch file, the vehicle does not shift out of first gear, and doesn't seem to be commanded to do so.

I checked the vehicle speed sensor (VSS) and connector at the transmission, it is good and tight, wiring from the VSS to the ECM has good continuity, and I scoped the VSS signal at the ECM and it is generating the proper AC sine wave signal that increases with transmission output shaft speed. However, the ECM is not registering a VSS signal (I checked with a couple of different enhanced scan tools), and if I unplug the sensor, no fault codes are stored in either the ECM or TCM. The TCM is seeing all the other information from the ECM via CAN (engine RPM, temp, TPS, torque input, shift selector), but no VSS. I tried changing the transmission settings and VSS output settings in HP Tuners with no change. I also cannot seem to access and TCM settings or data with the VCM Editor software.

Can anyone here please take a look at my attached tune file and check if any settings are incorrect that would prevent the ECM from looking for a VSS signal? I have the factory BMW speedometer working via the wheel speed sensors and ABS control module, so the actual speedometer settings aren't important, I just want the ECM and TCM to see the VSS so the thing will shift!


Thank you,

Chris

[radrace19]

It looks to me like someone set the ECM file to Automatic instead of Manual. Once you set this flag to automatic I've seen the TC-2 not read the correct info.
I've compared your ECM file to a know stock file and there were a few differences, but I know this one is an issue.

-Greg

[cda951]

Hi Greg,

Thank you so much for the reply, that did the trick! I had previously re-flashed it to manual and then back to auto as a sanity check, but I hadn't actually tried driving it with the ECM set to "manual!"

And for the record getting the body electrics of a 1996-2001 BMW 7-series to all play nice with the GM stuff is a lot more work than I could have imagained, thanks to the archaic 1990s-era BMW single-wire body buses. Slightly later models like the E46 3-series use CAN protocol for more of the body modules and HVAC functions, so there are plug-and-play CAN boxes for those . . . .

Anyway, thanks again!

[Brand New Classics]

It looks to me like someone set the ECM file to Automatic instead of Manual. Once you set this flag to automatic I've seen the TC-2 not read the correct info.
I've compared your ECM file to a know stock file and there were a few differences, but I know this one is an issue.

-Greg

Greg you are the man. I found this thread after 8 hours of double checking all my wiring, testing the Milla volts coming to the sensor, testing the sensor, replacing the sensor, Disconnecting my cruise control tach and speed signal wires. 6-8 hours of my life wasted because I changed the tune to automatic transmission. I changed the tune back to manual transmission and immediately the speedo works and it shifts properly. I greatly appreciate the time you took to chime in on this gentleman's question. It helped me tremendously. I was getting ready to light it on fire.

For anyone else running the Gm performance LS3 connect and cruise package with the 4l65e automatic transmission leave the tune on MANUAL TRANSMISSION.