E67 and TKO600 VSS

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10-17-2020
foxls2

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E67 and TKO600 VSS

I have an LS2 with a LSA supercharger, I was running it with an E38 ECM but recently switched to a E67 ECM so I could take advantage of all the support it offers
for the supercharger, the harness and ECM came from BP Automotive, I'm running a GM TKO600 and the VSS seems to not work with the new ECM, worked fine with the E38 ECM I set all the parameters to be like the E38 but for some reason I get a P0502 SES code. I've searched the WEB but only find stuff on the GM connect and cruise setups with T56 magnums, which mentions GM not supporting the VSS in the OP system loaded into those E67's? I've attached my tune file.
Any ideas? Thanks guys.
10-17-2020
Jon S.

Try setting [ECM] 820 to RepTOS.
10-18-2020
foxls2

speedo problem

Quote:

Originally Posted by Jon S.

Try setting [ECM] 820 to RepTOS.

Hi Jon, just gave that a try still not working, would you happen to know if the signal and low ref wires were crossed would cause this, I haven't checked at the ECM connector yet but was wondering because of the P0502 code. I read somewhere on one of the forums that GM's speedo logic was like black magic. Thanks
10-18-2020
Jon S.

E67 ECM J1 (Blue) pin 39 is the 4K PPM output to an electric Speedometer.

A manual transmission VSS input to an E67 ECM should be - VSS High to J3 (Grey) pin 66 - VSS Low to J3 (Grey) pin 67. It is a pulsed input, so sometimes having the wires backwards has no negative effect - but not always.

In a conversion project you may need to disable DTCs P0502 and P0503 - all that matters in the end, is that you have a functioning Speedometer.
10-18-2020
foxls2

speedo problem

Quote:

Originally Posted by Jon S.

E67 ECM J1 (Blue) pin 39 is the 4K PPM output to an electric Speedometer.

A manual transmission VSS input to an E67 ECM should be - VSS High to J3 (Grey) pin 66 - VSS Low to J3 (Grey) pin 67. It is a pulsed input, so sometimes having the wires backwards has no negative effect - but not always.

In a conversion project you may need to disable DTCs P0502 and P0503 - all that matters in the end, is that you have a functioning Speedometer.

Jon I have them disabled and you are right, I'm running a cable driven speedo, I just need the VSS to work for drivability issues that happen without it working, like DFCO and idle issues when coming to a stop etc.
10-20-2020
pannetron

I have an E67 ECU but Tremec T56 magnum so this may or may not help you. To get my VSS reporting correct, I had to make some odd looking settings in the Speedo tab. I set the VSS pulses per rev to 40, like they were in my original crate engine OS. Since my T56 outputs only 12 pulses per rev, I multiplied my axle ratio by 12/40 and put that value in the Final Drive Ratio fields. That makes my 3.60 ratio look like 1.08. I also set the Speed Output Type to VehRep TOS. The VCM Scanner now reports the same vehicle speed as my GPS speedometer and DFCO and a few other speed related settings behave as expected. A big win for me was that this made the reverse lockout output from the ECU correctly drive the RLO solenoid on my T56. I had to add a pin to an ECU connector to get that RLO output but it was worth it. I saw your tune has the VSS pulses per rev set to 17 so you might at least try a 17/40 factor on your 4.11 final drive if your TKO has 17 pulses per rev and set set the VSS Pulses per rev to 40 in the tune.
10-21-2020
foxls2

Thanks for posting Pannetron I tried your suggestions with both "serial" and "REPTOS" neither worked, guess I'll search the web to see if I can find anything on GM's E67 speedo logic. it just gripes me because it worked fine with the E38, and when I look at some of the CTS-V tune files on HPT some of then have the VSS pulses set to 17. Someone said that GM speedo logic was a black art, I'm beginning to believe them!
10-21-2020
foxls2

Because I hate threads that never show how the issue was resolved......
Turns out the harness maker pinned it like a 2013 ZL1 6 speed OS which uses J3 pins 71&72 where as I have a 2013 CTS-V OS which uses J3 pins 66&67 swapped pins and put everything else back and all is good now.
10-21-2020
Jon S.

Very glad to hear you got it sorted out - the RepTOS setting for the 4K PPM output generally works.

Also, in keep with providing good information for others to follow ....

Quote:

Originally Posted by foxls2

... Turns out the harness maker pinned it like a 2013 ZL1 6 speed OS which uses J3 pins 71&72 where as I have a 2013 CTS-V OS which uses J3 pins 66&67 swapped pins and put everything else back and all is good now ...

That above quote is not true. E67 manual transmission VSS input pins do not change across operating systems. Your harness builder (BP Automotive) simply mixed up the E38 VSS pins (71 & 72) with the E67 VSS pins (66 & 67).