GMPP LS3 with GMPP Controller Tacho control

[TurboCamaro]

I have done an GMPP LS3 with MPP Controller swap into an early Camaro and am trying to configure the tach output. However the CAL/OS, 12607096/19211212, doesn't have the Tach parameters. Is there a way to add these to the Cal or utilize another Cal and flash the PCM?

Attached is the Cal file I pulled from the PCM (Note: There were some incorrect checksums which I have updated in this file however have not yet flashed to the PCM)9070

[Taz]

Hello TurboCamaro,

An LS3 in a vintage Camaro will be great ride when you’re done ! Drawing a mental blank on the “MPP Controller” – marine ?

Is the wiring harness and controller from GM ? If they so, these are often setup with analogue gauge outputs.

Assuming the ECM is an E67, the “System” folder is present (where Tach parameters would be), but empty – in the tune you posted. A segment swap of a system folder from the same OS (19211212) would add the parameters you want. I don’t have this OS in my database – wondering if it’s a GMPP stand alone type OS.

Some addition information regarding the ECM and wiring harness would be helpful (ie. both from GMPP, etc.)

I responded to your post in this thread, as the link to your tune doesn’t work in the E38 / E67 / E37 thread.

Regards,
Taz

[TurboCamaro]

HI TAZ
Yes the harness and ECM is a GM Performance piece.

Thanks

[Taz]

OK … if the harness and ECM are both from GMPP …

The ECM OS will be proprietary … using a non-production OS.

The wiring harness will usually have wires (pinouts) for analogue gauges, for a transplant into a custom vehicle. These connections should include an analogue Tach output – check the instructions that came with the wiring harness for compatible tachometers, and required settings of the Tach (4 / 6 / 8 cylinder).

Given that these gauge outputs are analogue, controlled by the base OS program, there will be no way (that I know of) to adjust these via tuning software. You are probably stuck using compatible gauges (or gauge sensor input / output) as described in the instructions that should have came with the wiring harness / ECM kit.


Regards,
Taz

[joecar]

I looked in the tun file and I saw an early style VIN... I take it that it doesn't matter that the VIN doesn't match the late style VIN format, would this be correct...?

[Taz]

Hello Joecar,
...
Regarding your VIN question - I’m not 100% sure. The GMPP ECM is designed for transplants into non-stock applications. The OS is proprietary, and I don’t think the VIN entered by the end user matters.


Regards,
Taz

[68problemchild]

I am working on this same issue with a 68 camaro and a TIC TOC TACH. I read somewhere to trick the tach by programming it as a 4 cylinder and then the tach reads. I have an E38 PCM. not sure where to change the tach settings in the programmer.

Engine is L92 with VVT and LS3 intake.

I did find this. Not sure it applies.

9084

Current settings are

1201 = Serial Data
1202 = 2
1203 = 2

[Taz]

The diagram you have is for a tach “pull up” circuit. This often is needed if the tach pulses from the ECM are too weak to trigger the tach being used.

TurboCamaro has a different gauge problem than you. His GMPP tune does not have the tach settings in the system folder.

In your case set G1201 (Tachometer type) to “Crank”. The tach output will then be on connector C1 pin 48.

I’m not sure where to set your G1202 & G1203 values. In a Gen III with a 24x CKP these would be set to “6” for a 4 cylinder Tach (OEM), and “3” for an 8 cylinder Tach.

Not sure where to set the 58x CKP values … have yet to do an E38 conversion …


Regards,
Taz

[68problemchild]

That is awesome Taz. That should get me there. Thanks so much.

Sorry for the thread jacking....

[TurboCamaro]

Thanks guys.

We have used a tach adapter in other cars however it would be so much simpler to configure the PCM. Plus using the tach adapter the coil harness have to be cut into and spliced which is usually a recipe for a problem down the road.

The VIN is the VIN as it was supplied by GMPP, it has not been modified yet. I will be modifying it though as with the ?? in the first 2 characters I believe you do not get the extended PIDs with the scanner.

It seeming more and more like we should be using other sources of harnesses and PCM's. One of the cars is an automatic so the trans and engine have separate controllers. It would be nice to pin the engine controller to allow control of the trans however the tables are not in the Cal.

[ScarabEpic22]

For the new style GM electronics the engine and auto trans are controlled by completely separate modules, you just need to wire a TCM up and tie it into the appropriate circuits to have trans control. This is both an advantage and disadvantage depending on the car setup over the LS1 PCM that had both engine and trans control in 1 module.

Yes, you should change the VIN to be something like 1GN... so that EFILive can pull the appropriate PIDs for logging.

[TurboCamaro]

Thanks Eric

[ScarabEpic22]

Yep, Id talk to EFIConnection if you need custom harnesses made. I know a while ago they had a little bit of lead time, but they build them from scratch to your specs (length, auto/manual, LS1/E38/E67, etc) so that might be another option as well.

[68problemchild]

I know he is looking for a software fix down the road, but FYI.

This is giving me a working tach!!!

Now its off a bit, computer logger reading 750-800 and 1968 Camaro Tic Toc Tach reading 1000-1100 but heck it works. Current settings are

1201 = Crank
1202 = 6
1203 = 6

Taz, should I try "3's instead of 6's?

[Taz]

As before, not positive on E38's .... you're about 25% too high on the Tach ... try using 4 in each ... if that goes the wrong direction (ie. tach reading even higher) ... then try using 8 in each .... just guessing ... LS1-B man !!

It will take a little experimentation to get it right.

Did you need to use a "pull up" circuit, or did the ECM have enough power output to trigger the Tach ?

Regards,
Taz

[68problemchild]

No circuit. Straight to the TACH. Best result so far was "crank" and set others to "9"s.

Thx again.

[TurboCamaro]

It has been a while since this conversation has progressed. In reading back in seems the original question has been lost.

I am doing a GM Performance LS3 6.2L part number 192044097 with a GM Performance Controller in a 69 Camaro. The tach is operational however not displaying the correct RPM. I have read the Cal from the controller as an E67 (Cal attached above) and there is no control in the cal for the tach configuration. Has anyone had any success in configuring the tach in these controllers.

[Taz]

Thread got sidetracked ... apologies.

Do you have the instructions from GM for the ECM / wiring harness kit ? With no software parameters to edit Tach output, you're only left with hardware changes. I'm assuming the Tach is reading too high ? Similar to an analague Tach set to 4 cylinder, but connected to a V8.

Putting a resistor in line between the ECM output and the Tach should work if you are using the original '69 Camaro Tach. If your using an aftermarket analogue Tach, try setting it to 4 cylinder (rather than 8 cylinder).

Regards,
Taz

[ScarabEpic22]

TurboCamaro, do you have G120x tables in your tune? Im not at my tuning computer so I cant pull up your tune to check for myself.

Have you got the enhanced GM PIDs issue sorted as well?

[TurboCamaro]

No the tach tables do not exist in the tune. This is what I am trying to determine if there is a way to add them or reflash the computer with a stock LS3 cal or other?

I haven't addressed the advanced pids as of yet, first things first is the tach. Once the car gets closer to the dyno I will set the VIN and get the PIDs functioning.

No I don't have the GM instructions. We did one other car utilizing a tach adapter however you have to splice into the ignition wires and it in my mind is a rather poor solution. Typically in my experience as soon as you start splicing in it opens the door for problems down the road.

[Taz]

The longer the thread gets, the more we go in circles !

Current ECM & tune - can only copy segment from a System folder from another tune of the same OS - not very probable as this is a proprietary GMPP OS (non-production). Means wiring a resistor / tach adapter.

Current ECM - reflashing with production OS - as you know, E38 & E67 don't actually get a full reflash - require an appropriate "base tune" to already be in the ECM - not sure how this would workout with GMPP tune. May have to have a "base tune" loaded in the ECM via a Tech 2.

The last option - different E67 with appropriate base already installed (from auto recycler) - then tune from there.

Those are all of the options I can think of - personally, I would just wire in the Tach - pick the "best" place (away from known sources of moisture) solder everything, and seal it in 2 overlapping layers of shrink tubing.

Regards,
Taz

[TurboCamaro]

Thanks Taz!

Completely clear.

[ScarabEpic22]

Taz, you can full flash E38/E67s as long as you are careful and know that the new OS will not brick the ECM. For example, I bought a set of cores off a friend with an 07 TBSS OS and full flashed my 08 TBSS OS. Only issue was the VIN, I had to manually reprogram it. For a GMPP OS to a stock OS, Im not sure which ones work as I have not tried it before. E67s dont seem to be as picky as E38s from what Ive seen, just dont flash a 10+ OS into an 06-08 E67.

[Taz]

Yes, you can use the full flash option on E38 / E67 ... but my understanding is that doesn't copy over everything - like a full flash on an LS1-B style PCM. If the original (donor) E38 / E67 was from a V6 (etc.), that original "platform" would remain resident in the ECM, even after a full flash. Just need to confirm the "base tune" is compatible with the eventual "end product".

Turbocamaro - I should have used "lol" instead of "!" in the above thread #21 - was laughing, not frustrated. Hope I didn't misconvey that.

Regards,
Taz

[TurboCamaro]

No worries,TAZ. No conveyance taken.

I was thinking there would have already been some experience with the crate motors and controllers GM has released. It seems as though it isn't so therefore we have some learning to do. I think that it will probably be simpler on future builds to not use the GM Performance controllers rather use a custom harness and factory type controller.

[Taz]

Questions like yours seem common with the GMPP systems ... I've never used one ... but it appears GM should provide more "up front" information, or more detailed instructions. I'm guessing GM's intent was to allow the end user to setup the system without the need for any programming - hence the analogue gauge outputs. For an experienced person or professional shop, it limits certain tuning options.

Probably half of the transplants I've done have used a re-worked OEM harness (most cost effective option as the customer often gets the harness with the engine). Just takes a little time to make it look nice !

Regards,
Taz

[2000montecarlorwd]

Questions like yours seem common with the GMPP systems ... I've never used one ... but it appears GM should provide more "up front" information, or more detailed instructions. I'm guessing GM's intent was to allow the end user to setup the system without the need for any programming - hence the analogue gauge outputs. For an experienced person or professional shop, it limits certain tuning options.

Probably half of the transplants I've done have used a re-worked OEM harness (most cost effective option as the customer often gets the harness with the engine). Just takes a little time to make it look nice !

Regards,
Taz

It seems crazy to sell a performance motor/ controlling system and not have a "ready to go" tach setup.. Or like you said "information disclosed that your tach is going to take more time than your whole install" lol.