Getting the speedo working isn't the problem. Getting the ECM to read VSS so it can set OBDII readiness is.

In plain language - the Automatic has a TCM embeded in the transmission. It's writing the VSS speed to the ECM via canbus. With the manual transmission, the ECM is reading the transmission pulses from the VSS sensor. I believe that because my ECM is from an automatic, it lacks the programming to read the VSS pulses.

I think the sensor for a speedometer for a manual transmission was in the hub at least it was for my 99 vette. When you changed rear gears the speedometer was unaffected.

My plan was to use and GPS sensor for the speedometer and the Dakota Dash convertor. I hadn't researched far enough to see what the ouput of the GPS was , but I would guess it is a pulse.

Dakota sells a tunable pulse input speedo. I was looking into them recently.

The next person that mentions a product to drive a speedometer gets the hose. Y'all missing the point.

I did a bit more reading last night about flashing the ECM - E39a ECM's are reflashable via J2534 interfaces that can be had for about $40 (Hurrah for congress - 2004 law states manufacturers can't lock out independent mechanics) - much more palatable than your $1000 TechII scanner or $1500 GM MDI interface. You can also buy a 3-day trial to GM GDS2 (Global Diagnostics System v2) for $57, which gives access to tis2web (repository of the various firmwares).

However - it looks like nearly everything is based off the VIN. Doesn't look like you get to pick and choose the modules (unless they have a associated TSB for corner cases).

I've also run across some annoying news about GM's "Global A" program - under the purpose of preventing the reselling of stolen car parts, modules are encrypted to prevent interoperability in a different car. The article I read was lacking a lot of detail - but remember those stereo's that wouldn't work unless you had a special code? Imagine that, but for a fuel pump control module. Or transmission module. Or ABS controller.

Aside from that annoyance, which I don't think I have to contend with unless the ABS controller somehow uses the wheel speed sensor on conjunction with the driveshaft sensor for traction control and vehicle speed - I think I have plan(s) of action - my 3 options are..

A. Take ECM to dealer for reflash - ($110). Get laughed at when they say they won't do a standalone flash. Get laughed at more when I show up in a Mazda and ask them to reflash. Assuming they'll do it (which I'm doubting - never trust a service manager) I'll probably need to provide a VIN from a manual transmission'd car to get the bits I want, which'll mean using 2 more credits on HPTuners ($100). $210 total.
B. Snag a J2534 controller, flash it myself ($90). Program for another VIN. HPTuners ($100) again. $190 total.
C. Grab another ECM ($50 - $150). HPTuners ($100). $150 - $250 total. Upside - I have 2 ECU's.

C seems most palatable. I'm off to make some phone calls.

Edit: Phone calls complete. I've got a '14 ECM from a manual coming my way for $65.

How did V8 roadsters get around it? They used a different fuel pump with a manual regulator and tuned around the pressure changes. What does it need for the transmission if its a manual? Also, did their ABS just not work?

I'm a gm tech all our reflashes are based on what vin the mdi reads. Basically it reads the vin then the service programming system (sps) decides what calibrations are available. Only thing you can really select is for older calibrations or there might be certain calibrations available based on the rpo code. Now it is possible to manually input the vin into sps (Ive done this once or twice when installing a junkyard ecu) but your still stuck with only the calibrations available for that vin.

Did the automatic car have a tcm? If it did the ecm is expecting to receive the speed signal from the tcm over the high speed data bus.

Thanks for the verification - :likecat: - I figured there's also hoops to jump through to have a dealership reflash to a different VIN. Engine (and harness) originally came from an auto with a TCM that's long gone. I've stripped the automatic wires out and added VSS wires to the Replicated TOS inputs on the ECM.

Hopefully it'll all work out when we get the car back next week.

ABS is still a Mazda module, no tie in with the GM stuff. And - again - I hope with the new ECM all this VSS stuff just starts working.

Forgive my ignorance. Trying to get a grasp of what you are trying to accomplish. VSS, Vehicle Speed Sensor - you're saying the ECM needs this signal? What happens without it? Does the engine shut off or does it reed it to change the tune? The previous generation of LS engine only needed it for an automatic transmission (gear changes).

Judging by his comments regarding the "OBD-readiness" condition, it will throw a CEL. Which in turn, will not allow the car to pass emissions as the Miata chassis is an OBD2 VIN. No emissions pass on OBD2 car in GA (county dependent) = No registration.

According to gm service information that 14 ecm has two possible vss pin outs depending on what rpo the trans was.

I put in a call to v8roadsters and got some more info. Long story short - I made an assumption.

There's 2 versions of the ECM - the E39 and E39a. E39a, on top of having this VSS issue I'm seeing also requires the body module to control the alternator. This could be worked around fairly easily by using a standalone circuit to control the alternator (similar to what megasquirt does with NB's with PWM) instead of the ECM.

But my E39a VSS issue - if I had some time with a V6 Camaro I might could figure it out. My guess is there's communication between the ABS wheel speed sensors and the ECM/TCM for StabiliTrak.

Which is silly. In HP Tuners you just just turn the related codes off and it'll autopass the readyness monitor and wont light the CEL. Of course that is for offroad use only.

Is there any specific wiring diagrams or connector pinouts you need? Also if you have a vin # I can pull up what rpo codes that vehicle was equipped with.

I always forget HP Tuner's integration with this situation, and how compatible it is with emissions laws. Doh, you are correct, I remember this now from a buddy's Colorado he had tuned on HP Tuners, it was nice to just "turn shit off".

Finally set out to build my cluster today. This is a SpeedHut gauge set inserted into the OEM cluster. Pretty pleased with the outcome and not too hard to do. If anyone wants a write up I will be happy to do one.


https://www.miataturbo.net/attachmen...ine=1459028240


SpeedHut gauge set in the OEM cluster.

Yes please do!

Some encouragement for you guys:


Ran the car yeaterday at the DC SCCA test and tune autox. Car ran great, no issues whatsoever with over 30 runs. Throttle is very sensitive and very easy to pick up too much speed even on 205 series R compounds. Next task is going to be to step up to 275s.

Sounded awesome from outside the car. I'm running a tein monoflex suspension and Re-71r's, the same as last year, and there's no noticable change in the handling characteristics other than than lots more power. Still very nuetral, very balanced. All in, super happy with the swap.

What are running for an exhaust? Dual 2.25 into a single 3?

Gooflophaze, If you need a hand pulling signals let me know. I can probably find a v6 Camaro to go rent. I don't have a data analyzer, but I do have a four channel digital O-scope.

Thanks for the offer Cujoel and B6Tfastiva - for the moment, I think I've got everything (well, everything except for an E39 ECM - that'll be my priority this week). I may loop back around to get the E39a working at a later date.

Tow vehicle decided to be a punk when the exhaust was finished on Friday. Thought it was the batteries, hooked up the charger, no joy, took them to autozone, tested, nope they're fine. Googled for why it wasn't cranking - oh, those ignition switches are known to be a PITA. By the time we swapped it out it was late on a Friday before a holiday weekend.

Today, cranked the diesel back up - since its resurrection the fuel gauge has been kaput - went to fill it and reset the odometer - and proceeded to get stuck in the gas station for an hour. Finally smacked the starter the right way and retrieved the miata. Just let the truck idle the entire time.

https://www.miataturbo.net/attachmen...ine=1459206442

2.25 y'd into 2.5 with (I think) a 3in resonator.

I took a video of the exhaust and a couple of free revs, but my cellphone doesn't do it justice. I'll need to break out the gopro.

Yup, 2.25s into a single 3 with a magnaflow muffler - i just modified Enthuzas single LS exhaust to fit. Jason sent it with everything in front of the Y unwelded and it worked great. It's starting to break in well, seems like less rasp.

The car revs up pretty quick, like a bike. Are you running an aftermarket clutch/flywheel or a stock combo?

Stock Combo. Its pretty heavy. Almost dropped it on my finger during the install.

Didn't seem like going aftermarket was going to save me a lot of weight looking at how thick the Spec flywheel is to eliminate the dual mass design. Clamping force and disc material is surely better than stock, but my car is significantly lighter than a camaro, so decided to run a stock setup especially once considering the cost side. But yeah, even with what felt like a 40 pound flywheel/pressure plate/disc combo, it revs really quick and is super responsive. Would consider swaping to aftermarket if some better options became available or we burn up the stock setup.

The stock setup is smooth now that we have the clutch adjusted just right. Such a great car to drive. Very impressive.

Just had my first start up... WOO HOO! Now I just need to pull the motor and tidy up the wiring over the weekend and it is time to see what she can do! Thanks to everyone for all the help.....especially you Gooflophaze!

woo-hoo indeed!

Just a heads up - in my guage write up i listed pin 3 as the ground on the VSS connector. That was incorrect - updated image below.

Pin 1: pulse output
Pin 2: Ground
Pin 3: ignitition power

Anyway we can update the original post to prevent anyone from wiring this up wrong?


[QUOTE=1999LFX;1312249]

On the speedo, I haven't driven the car yet, so can't completely confirm this works, but you need to pick up the speed output and ground off the vehicle speed sensor. This is wires 1 and 3, respectively on the connector. Once you can drive the car, you will drive to the preset speed and set the speedometer to that speed, so you will need a gps unit or phone app or friend. One option is to just upgrade to the GPS speedo unit - not a bad idea and something I wished I had done. The speedhut gauges are compatible with other gps sending units, so still an option.

https://www.miataturbo.net/attachmen...ine=1460291489<br >

Anyone able to verify the reference voltage for the VSS? I assumed it was 12v since it states run/crank.

12v.

Good news is that we got the car tagged. Bad news is that we're still fighting for a VSS reading from the ECM. I snagged a J2534 cable and a 2 day subscription to GM's SPS to reflash the ECM.. turns out you can't. GM locked down what they called "off board" programming, so if it's not flashed in a car with a BCM, FPCM, ABSCM, WTFBBQCM present it won't allow a flash. After more research, it looks like EFI Live is superior to HPTuners in changing options, including disabling the BCM that forces the VSS to be picked up by the ECM via failover.

Now, normally I wouldn't give a flip at this point and would just go ahead and focus on getting the speedometer working by reading the VSS signal directly.

But after spending a considerable amount of time looking at E39 and E39a tuning, VSS plays a fairly significant role in torque delivery (and misc. other options). More than anything, I'm disappointed at the lengths GM has gone through to crippled their software.

Quick question to those with running cars.... What did you do for cooling fan wiring? I tied into pin 59 on X1 with a diode, just to be safe, and on my first full temp run up my fan never kicked on. I had a coolant leak so I was more worried about that than I was to check to see if I had 12v going to my fan relay. Just curious as I get ready for my next full temp run.

Are you running HPTuners? VCM Scanner has the option to turn things on and off for testing.

I also found that the LFX wants to run a little warm by stock. Our firstish start we saw temps hit 220 without the fans kicking on so we shut it down - turns out the fans kick on at 222f or 195f depending on "torque zone" and vss and rpm.

I could attempt to program it in a camaro if you shipped it to me. I think we still have one siting out on the used lot if not I'd have to wait for one to come in for service.

If we weren't this close to the mitty, I'd take you up on that. But at this point, I'm not sure if anything short of EFI Live with their option of disabling the BCM that HPTuners doesn't have will get the ECM to play with the VSS. Too many TLA's.

Oh - and this is kinda neat - with raspberry pi you can throw on a mcp2515 board (if you bring SPI down to 3.3v) and there's a kernel module that'll introduce berkley sockets so you can run tcpdump (candump) and a slew of other nifty utils. It's nice because you can capture frames at the full 500kpbs instead of relying on serial (that's only 115kbps). There's also python and c libraries - I just wish I was as proficient with my python as I am with my shell scripting. I've got a rpi zero that I've hooked up via serial console to my laptop, wired in a potentiometer to the coolant (and oil pressure) sensor, and was able to identify the gmlan packets and bytes by seeing what changed as I sweeped the pot. The nice thing about using the gmlan packets is I don't have to load up the bus with obdii requests. </geek>

I'm still playing with scaling the coolant gauge and seeing where the LFX wants sit naturally. In traffic we hit 222f, at speed it sat around 190-200f - this appears to be in line with what camaro5 forums are reporting. We'll need to fabricate an undertray before we get the A/C working and fighting the Georgia summer for sure. I'm still slightly confused as to when the fans are supposed to kick on - there's a hi fan and a low fan, torque zones and RPM and VSS.. and a stock 180f thermostat.

https://www.miataturbo.net/attachmen...ine=1460599253

Right now I have the nb cluster gauge scaled from 160 to 240, so it sits pointing straight up at 200 and 2/3rds at 220. I can make that less prevalent by increasing the scale from say 100 to 300, or applying some math to it. I might miata sender resistance curves and try and ape those.. plenty of ways to skin that cat.

And again.. Sorry for the lack of chapters, been busy doing all this stuff and more. Got new rubber on 6ul's yesterday along with an alignment. Hood is back from paint and looks good. I'll try and snag a better picture in the sun, but it looks nice and subtle.

https://www.miataturbo.net/attachmen...ine=1460599253

Is that the hood you were working on? Looks good.

That's weird they change they temp so much. I guess it's for emissions.

Looking for ideas to cleanly and securely mount the ECU. Any photos/ideas you guys can share?

GM PN 22897960. Our dealer had it in stock as they tend to break. Was only about $10 if memory serves.

https://www.miataturbo.net/attachmen...ine=1461389318

It's a plastic(composite) mount. We shaved the extra bits off the bottom to give a flat mounting part.

https://www.miataturbo.net/attachmen...ine=1461389318
We trimmed one of the headlight bucket braces underneath the fender to give us an additional 1.5 inches so we could tuck the top part of the ECM underneath which made a HUGE difference. The biggest problem is trying to find a good position that the harness will allow.

Once we had the position, we used some fat rivets to attach a piece of flat metal we bent and drilled to meet a hole that was already threaded m6x1.0.

https://www.miataturbo.net/attachmen...ine=1461389318

Found a pre-threaded hole behind the headlight bucket - it's at an odd angle, so we bent the flat at roughly 45 degrees, drilled the hole for the bolt, positioned the mount while twisting the flat into submission, drilled and riveted. Nothings exactly square in this area..

https://lh3.googleusercontent.com/-d...423_011004.jpg

After that, we bent a piece of flat into an S, drilled a hole into the fender well, ran a bolt from there to the S bracket, and from there onto the mounting tab (we had to cut a gusset out of the composite - it'll make more sense when you have it in your hand unmolested).

https://www.miataturbo.net/attachmen...ine=1461389318

It's not going anywhere. Pretty happy with how it came out.

https://www.miataturbo.net/attachmen...ine=1461389318

Yea that looks really good. I'll dig up the part number and post it up later today.

Found it - it was buried in a different subsection - 22897960

Any chance you have a shot of the underside of your hood gooflophaze? I am about to start modifying the hood to clear and I'd like to have a good reference of exactly where I am going to have to make clearance.

nice meeting you this weekend. do you have any drink tickets?

OBDII connections
 

Question on the OBDII connections. The ECU is signaling the CEL and I am trying to get a scanner to work so I can see what the issue is. I am using the cheap bluetooth scanner I have and I can not get it to talk to the ECU. Hopefully someone with a working conversion can help me figure out what pins need to be connected.

I know the following for sure:
4=Ground
16= 12v

The pinout shows 12 and 13 are the CAN + and - respectively but that is not working. My research on the Web has only added more confusion...LOL

does that bluetooth work with other cars? Sometimes the cheap ones are DOA or super flaky.

Where do you see 12 and 13 being CAN high and low? I thought it was standard that 6 and 14 were CAN HIGH and CAN LOW respectively.

I put in my other car and it worked just fine but you are 100% correct.....it was a PITA to get working with my phone. I would go buy a "real" scanner but I live out in BFE and was just trying to get it working with what I have on hand.

So there's probably some confusion stemming from 2 highspeed GMLAN's being output to the OBDII connector.

6 High, 14 Low - This is the SAE standard. This is the one you need to run the wires from the ECU to.
12 High, 13 Low - Optional Additional from GM

https://www.miataturbo.net/attachmen...ine=1465526198

That is from the OBDII pin out for an LFX Camaro. everything else has been 100% in the wiring diagrams so I trust it personally.

WHy not just use the scanner function built into hp tuners?

OK....I will try those now. Are there any other wires that are needed?

Sorry for spamming your build thread but I was hoping this would help the next guy...

I had V8R program the ECU so I do not have HPTuner...yet. I am hoping to install an e85 sensor and upload a table down the road but for now I just want to see what the LFX is complaining about.

Power and ground(s). 16, 4 + 5. https://developer.mbed.org/media/upl...GdyXCBV7-t.jpg

Leafy - I'll need to post an update about it, but the Torque app saved my ass last week. Besides - you'll need the proper pins to get Hptuners to work as well. :)

Still no joy.... Forgive my ignorance but is there a difference in an error code reader and a full blown scanner as it relates to interface ports on the OBDII? I ask because I am wondering if the scanner is looking for serial data on pin 2 to establish the OBDII interface connection rather than just talking to the ECU via CAN Bus the way something like HPTuners may do.

O well.... I will research a bit tonight and try again tomorrow.

Nope - 4, 5, 6, 14 and 16 are the only ones we have hooked up. The other pins, like J1850, are non-canbus based OBDII protocols. OBDII has been standardized since 96, CANBus as the primary OBDII protocol wasn't established until 2008.

I found it....

As you like to call them gooflophaze..."pro tip":

If your harness happens to be out of an auto the transmission has an internal loop that goes to and from the ATX-Q8 connector. Fell back on the good old rule of "when in doubt...ohm it out". 1 unloomed ECU harness and 2 hours later I now have a working OBDII port.

12 and 13 are only used if the vehicle has a chassis expansion communication bus. I pulled up a 13 camaro wiring diagram and the only modules on that bus are the abs, power steering, steering angle sensor, suspension control module, and multi axis sensor.

If someone could verify that they have 12v on pin 5 of their MAF plug (pink/blk) I would greatly appreciate it. It looks like it should have voltage via the schematics but I'd like to verify before I just start throwing 12v to something.

All of my error codes are linked to the multi-function MAF sensor and again I traced the wire back to the transmission plugs that went to the auto. I guess I would STRONGLY advise others doing this swap to just fork out the coin for a standard trans harness if your motor was pulled from an auto.

Pretty much everything pink/blk is fused 12v in GM. It looks like you're looking for F14UA fuse, which is.. maf, iat, vss, fpcm, reverse inhibit solenoid, skip shift actuator.. so it makes sense that it'd shoot to the tranny plug.

Gooflophaze, It's been a while. Did you get all the gauges working?

fyi, I found a controller for the fuel pump. They use the tach signal to detect the engine running, primes and shuts off

Fuel Pump Safety Switch

It's been a while since posting, but I wanted to give you guys still building a little encouragement. Have done a lot of autox since the LFX swap, but finally got around to doing my first track day. Within my group, I was able to keep up with the vettes and 911s, and in the below video was running with a really nice GT40. I couldn't be happier with the setup. Driving the car has been a blast, but it's been a lot of fun talking to people that stop by after each run to check out the car after seeing it on track.

Little traffic in the first two minutes, but after that things open up and get a lot more fun:

Awesome!