Mazda Miata Auto To Manual Swap Guide (NB)
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- čas přidán 29. 03. 2024
- Today we're covering the basics of an automatic to manual transmission conversion for a 1999 Mazda Miata. Below is a full description of the wiring that needs to be completed that will allow full functionality of all systems.
Neutral Safety Switch
Find the large connector that used to hook to the side of the auto tranny. There are two heavy gauge wires - Black with Blue Stripe and Black with Red Stripe. These can simply be spliced together and the car will start. You can also tie these into the two small single wire white plugs coming off the top of the tranny. That will require the car to be in neutral to start. There is no polarity to worry about, as it is just a switch.
Reverse Lights
The other connector coming off the manual tranny that has two conductors and close to the neutral safety switch is the reverse lights switch.
On the same large auto connector you found the neutral wires - look for the Red with Yellow and Black with Yellow wires. Splice these together with the two wires from the small connector you just cut off. Again, polarity is not an issue.
Speed Sensor
Connect the speed sensor on the transmission to the Yellow and Orange wires on the car side. (one of the dangling connectors has yellow and orange wires, pretty easy to locate) Unclear if polarity matters.
Speedometer
Splice together 2 pairs of wires that were going into the Automatic Transmission ECU with the following colors.
Connect Black/White to Orange
Connect Yellow to Black/Blue (Ground)
Cruise Control
Cut the purple wire going into the Cruise Control ECU (driver side under dash)
Hi, Great video! I completed the swap on my 99 Miata. I jumped the wires that you indicated and the speedo, VSS, and the neutral start work. Now my CEL is on with P1601 ( no comm between ECU and TCM) how do i trick the ECH so it thinks that it doesn't look for the TCM?
Just bought a car with this same swap fixed some of the wiring thanks to your video still have a vacuum leak i can’t find, some one said there is a vacuum line that runs to the auto trans that gets capped when you swap it ? Any info would be greatly appreciated
That’s true for 90-97 model years, it should be on the back of the intake manifold near the firewall.
Great video. I just did the same swap on my 2000 Miata. I jumped the wiring as you described and got the speedometer, the neutral start, and the back up lights working. The car drives great, but the check engine light is on with a code P1601 ( no comm between ECU and TCM) How do I trick the ECU into not looking for the TCM ( that I removed as part of the swap). I found a procedure for a NA car but the ECU is different on a NB car) OBD1 vs OBD2)
I don’t think you can “trick” it. I always swap in an ECU from a manual car
Hey amazing vid ! I just finished the job cars running. Great, but I have a p1601 I’m assuming it’s from the rest of the wires from the tcu? Do I need to do anything with the rest of the wires not being used from the tcu clip ?
This video is NB specific, if you have an NA there's a wire from the TCM to PCM that needs to be grounded, I can't recall the pin or wire colors off hand. But grounding that wire will make the PCM think its a manual transmission, if it's an open circuit it will set a fault. (I'm making some assumptions here hope it helps)
Purple/ green to pink and black from tcu clears it
@9tonito Thank you for commenting with this information. It helped me out big time!
Great job... I'm impressed.
May I ask what someone should budget (lead time + $ + shop time) for an experienced mechanics team (like your group) to perform this task?
We estimate $2900 for the complete job, which includes parts, labor, taxes etc
@@immortanautomotive9221 thats acutally a lot cheaper than I expected. Another question, is this a one man job with a floor lift?
What if I already have a manual ECU can I use that instead of the automatic one do I have to splice anything as well?
You still have to do everything shown
Not too bad, there are a lot of low milage great condition automatics out there. Swap in an LSD at the same time and you are all set.
Yep! Would be easy to do the diff too while you’re in there!
hello thanks for the video, ive completed the swap did the wiring have no lights on the dash. when driving my rpms rise up to 1500-2000 when in neutral at a light.pror to the swap everything was working fine and even a little after words. any chance youd have the slightest idea of where i went wrong. i did not swap the ecus out or do anything with the tcu wires besides the ones you mentioned do these things come into factor at all, all other tcu wiring in the description is done. i have a 2001 miata nb2
ive already tried switching the wires around on the neutral switch and also changed it and did not improve.
Sometimes I’ve found that adjusting the throttle stop or idle screw helps, I assume because there’s less drag at idle with the torque converter gone.
Gotcha will try that just wanna ask if you still think it’s that Even if the idle problem isn’t always there it comes and goes and sometimes seems like it’s gunna die.
Thanks again!
wait you were able to get no lights on the dash without having to switch the auto ecu to the manual ecu ?
@@heyimpika_I swapped the ECU
Are there any different wiring steps for an nb2? Wifes car is an auto and ive finally convinced her to swap it after the last autocross. Need a manual ecu for no cel or other lights? Just going to start scavenging parts shortly amd want to make sure im not missing something.
NB2 is trickier because it has an immobilizer, if you swap the ECU you’ll also need to install a marching immobilizer, ignition cylinder and key. Fundamentally it’s the same though.
Any issues from not swapping the ecu other than cel on all the time?
I’m honestly not sure what will happen, try it and let me know 🤷♂️
Will do! Have to gather parts first. 😂
My car now crank no starts after swap, no spark, no rpm signal any ideas?
Check the wiring on the neutral safety switch. I’m doing a swap on my 2001 my trans is in but no wires are plugged in and same thing no crank so start. Other thing is maybe he switched the ecus ?
@@9tonito nope it was something that had nothing to do with the swap lmao, crushed a wire between trans and engine and it was blowing ecu fuse it starts now
😂😂😂 shit ima have to look at my wires to make sure I didn’t do the same thanks!
Ah yeah that makes sense! I didn’t think it would be swap related
is all the wiring you need to do or is there anything else
That’s all
@@immortanautomotive9221started Saturday and finished swapping my 99 today it all worked first try thank you 🙏
So do I not need a manual ecu
I always use a manual ECU
@@immortanautomotive9221 so do I need to buy a manual transmission ecu and a engine ecu?
Ok let’s be more clear here. PCM (powertrain control module) is for the engine, you should get one from a manual car.
TCM (transmission control module) only exists for automatic transmissions you won’t need one at all for manual.
ECU (electronic control module) is a generic term that can be used to describe any device that has a computer in the car pretty much.
@@immortanautomotive9221 thank you so much I got a nb Miata for cheap with a auto and I’m trying to find a shop in the Kansas City area to swap it for me
Where are you located?
Southeast Michigan
I did the swap but got a P0704 code.
Did you modify the cruise control wiring as described in my instructions?
@@immortanautomotive9221I did not. So just cut no need to wire it to anything?
@@kaushiksingh6493 correct
@@immortanautomotive9221 ok ill give it a go
@@immortanautomotive9221same code came back after cutting the purple wire. I should say I don’t have the clutch switch in
So the customer will only pay 2900 for everything
Yeah that includes everything
@@immortanautomotive9221 hopfully most shops charge that because my car was very clean and low millege it was just a auto