DIY: Test Neutral and Reverse Switch
 

This DIY will show you how to easily test the neutral and reverse switch on a manual transmission.

1) Jack-up driver's side and support vehicle with jack stands.
2) On top of the transmission, about mid-line, you'll see four connectors... two white and two black.3) Remove both connectors for switch to be tested.
4) Use a multimeter, set to 'ohm', and attach a probe to each connector.
5) Have the shifter in neutral and observe multimeter's display:6) Now put the shifter into gear:7) Observe the multimeter's display:8) Reattach connectors. It doesn't matter if you swap the connectors, just as long as the colors match (white to white, black to black).

Ok, seems to be a good place for this question. Is there any kind of reverse lockout that is supposed to be active while driving? I have occasionally ground reverse instead of going into 6th (I know, driver mod..). IF there is supposed to be a lockout, is it mechanical or electrical?

Yes, there is a physical hard stop... here is where its located:
Attachment 158814
The shifter itself has a tab that sticks out and hits that hard stop, preventing you from going into reverse.
This is why you have to press down on the shifter to get it into reverse... you're moving that tab under the hard stop.
Might be best to pull-up your center console and look at it... see what it looks like.

Yep Jonathon is right ..again..;)...as always...:)

I would buy you a beer or put a prawn (shrimp) on the BBQ if you ever came Down Under.....YOU are a Great help to all here, you give great advice..

The Series 2 RX-8 is similar, except Reverse is PUSH DOWN and Left UP.

Sephitrask, Don't know how you are getting Reverse Gear unless you are pushing down when shifting or your Tab (Mazda # Y601-17-571A WOW $53 ) is also worn or busted as Jon shows??

Fixed ;)
I know... being picky...

If I ever fly out that way I'll take you up on that.
Though seeing as I've never been further west than Ohio (where I live), that shows you how I am with traveling :lol2:

I honestly didn't know that... learned something new...

testing
 

Very thorough explanation. since im trying this with the tranny still installed are you testing the male or female ends. It looks like the female ends in the pic but I wanna be sure. Thanks again for the post.

It would be the male ends. The connector has a flat blade style contact.
You can easily follow the wire from the neutral switch since its a couple inches away.

Lets Clear this one up First....

The Reverse and Neutral Switches on Series 1 RX-8 6 Speed Manuals ARE NOT the same.

Mazda NAO have corrected their erroneous superseding which cause so much confusion for many years..

Y611-17-640A Neutral and Park Switch

Y612-17-640B Reverse- Back-up switch

Auto's do not use these switches they have a single larger unit incorporating gear selection switch...called an Inhibitor Switch

Please do not use my thread as a source to complain about your feelings toward the general population of this forum.
Comments like this could prevent people from helping you and welcomes argumentative members to crap all over this thread.

Could my reverse switch be stuck if my reverse lights dont turn off even when ye car is off?

Two questions
1) Have you recently done work with the reverse lights such as changing the bulbs?
2) Do you have an MT or AT?

Man I just got the code p0850 and im goin to try this. Love searchng and finding how to do it right thanks again, Grasshopper lol (jon ) you always have a good answer to a fix or how to look and see if you need to change or test something,.
Thanks

thanks jonathan. this was very helpful.

Thanks very much for the pics! Just had to do this last weekend.

Now, how hard is it to replace the reverse switch?

Edit: Turns out it was pretty easy...

Does anyone know how to remove the neutral switch when the transmission is still on the car? I was trying to look for a socket like the O2 sensor socket that is 26mm, but no luck...any advice is welcomed.

Think a crowfoot wrench would be your best bet.

***View this on my thread it looks better****

So I was able to fix the neutral switch on my own with the transmission in the car. Tigth fit but with Husky's Universal Pass-Through sockets it was a breeze.

Order from Mazmart.com RX-8 Neutral & Park Switch (2004-2008) - Manufacturer part number: Y612-17-640B - $95 part+2 day shipping

Also pickedup Husky Universal Pass-Through socket set, used then returned it back to home depot...all within 2 hours. You need a 27mm Pass-Through socket. - $130 (But I returned it so $0)

1. Jack up the driver front side of the car.
2. Support with Jack stand for safty.
3. Locate the neutral switch shown below
Attachment 287034
4. Disconnect 2 white clips
5. Thread clips through pass-through socket - 27mm
6. Carefully remove neutral switch
7. Install new switch
8. Remove jack stand and jack
9. Clear the CEL P0850 code
10. Have a bear and then go for a ride

Attachment 287035

New on left vs Old on right
Attachment 287036


***If your car is idling weirdly and using a lot of gas and you got CEL P0850, do your self a favor and replace the neutral switch asap.***

Jon316G, thanks. I ended up picking up a set of pass-through sockets, and it worked like a charm.

Hi,
I have question about reverse switch. Is there any chance to search reverse switch, or any cable connected to it, from interior? I want install parking camera to RX-8. The camera is connected to reverse lights. The LCD for this camera is connected with camera wirelessly. The LCD is connected to +12V cable to lighter. But the receiver (for camera signal) heated and I want connect the receiver for +12V cable, which has heads to/from reverse switch or any cable, which in voltage only, if i have shift into reverse. Is any chance to do it without decompose transmission from car? Could you anybody send me photo of position of it or write me a instructions? Thank you for help.

PS: Sorry, i forgot send info about rx-8. So it´s Mazda RX-8 2004, Automatic 4-level transmission (141 kW)

Very old thread, but just an FYI to add on here: On the S2 transmission, the black connector is the neutral, and the grey is the reverse, so kind of the opposite of the S1 trans.

Just wanted to share my appreciation for your input in this thread! Saved me a headache while doing a S2 transmission swap into my S1. Thanks!

I'm glad to be of help.

I bought a 26mm socket and cut a slit up the side of it. Worked great.

yep

hi, I need your help....I recently changed the S2 Transmission, but Neutral Switch is no work,
I want to know Neutral Switch of S2 is the same as S1?

Hi, I just got my 2004 RX8, and need to replace the "Reverse Switch". I bought Y612-17-640B from Ebay, but Sake Bomb said it is wrong. I checked carefully in this thread. Some said 640B is Neutral, some said 640B is Reverse. Could any one help to clarify? I'm planning to order directly from JDM-Planet. Thanks a lot!

640B is neutral. Y611-17-640A is the reverse.

Thank you Killawatts!!

Finally got the correct part, PN is Y611-17-640A for Reverse Switch (Black connector with an o ring as shown on picture). The explodes 3D drawing in this thread shared by others has been misleading everyone for years. It shows the Y612-17-640B on the Reverse Switch side. Most of us were fooled by that drawing and picked the wrong PN. Hope these pictures will help other RX8 owners to pick the right switch they need when search in this Forum.

Also, just to share with those who don't know how to DIY, we were charged 0.7hour*$165+ 75W-90 Gear Oil $28 + Tax 2.59 + Fill Oil Labor 0.5*$165 = $228.09 Because they said when replacing the switch the gear oil will leak a bit. The cost of switch is $79.98. Just to keep your hands clean by getting someone to put the switch back, the total cost is $308.07 in Bay Area. Oh, I forgot to add on two trips of UBER, over $50.

After dealing with issue, I will need to fix my power steering light. Left the car at the garage for half a week, nothing found, even I provided the feedback from dealer. They said the issue was intermittent and charged me 0.5hour*$165 = $82.5 for "check and advice, and inspect harness for damage" (by the way, my RX8 was with a customized intake, no need to remove tons of parts from the original intake. Anyway...... I will check on other repair shop after this experience or start to learn how to take care my new baby from now on.

https://cimg3.ibsrv.net/gimg/www.rx8...9987ce04d9.jpg


https://cimg3.ibsrv.net/gimg/www.rx8...ea9e48a35c.png
This is indeed Y611-17-640A, not 640B as sown on the exploded drawing.
https://cimg2.ibsrv.net/gimg/www.rx8...d994b17bb4.png

https://cimg5.ibsrv.net/gimg/www.rx8...3edb383916.png

no, different transmission manufacturers, different sensors, different electrical connectors between the two.
.

This was all the help I came for.... but a question arises. It's discussed in this thread that if neutral switch is disconnected idle is going to be crap. What happens if the reverse switch is not connected? Looking under my car one of the black connectors looks like it was not plugged in but I've had no issues with getting into reverse and my reverse lights operate just fine. I'm trying to determine if I unplugged it and forgot I did before I snapped a photo (I'm removing my engine harness), or if it has been disconnected this entire time.

I think its the clutch switch that screws up the idle......

no, the rpms will surge up and down ~1000 rpm in neutral if the neutral switch is not detected or bad/defective.

I had a trans rebuilt and the shop put a sealing washer on the neutral switch, but it doesn’t have one from Mazda. So the thickness of the washer wasn’t letting pcm receive the switch signal and it had that problem. I’m not even sure how we figured it out, maybe on a code reader. It was a ling time ago, but the same thing happens if the switch is bad or one or both connectors are unplugged.

It may not need the switch or not cause the same issue with the Adaptronic pcm is another thing to consider.
.

So if one of the reverse connectors (black) wasn't connected what would happen? Would you even notice while driving the car? Would it prevent the trans from engaging reverse?

no, it’s just a switch that turns on the reverse lights when engaged; there’s a notch in the gear selector shaft that determines this, same for the neutral switch, that’s all they do/are

if you look at the switch photo in the previous posts above; the ball-shaped piece on the end of it is internally spring-loaded to extend outward as in the photo. So when it’s in the notch on the shaft it can extend fully, otherwise the unnotched section of the selector shaft keeps it pressed inward and not engaged.
.

Beauty thanks, I must have unplugged the first connector before my brain caught up with me since my reverse lights were working haha

the plugs look the same for both switches, so possibly it was for the other, not really sure how to explain it because obviously as a simple on/off continuity switch it can’t ever make continuity if one on the two wires is disconnected :dunno: so logically the simple conclusion is ….


https://cimg4.ibsrv.net/gimg/www.rx8...376c89134a.gif
.

Yes we are saying the same thing, it had to have been connected for reverse lights to work. While prepping my engine for removal I've been labelling everything and taking photos before I start disconnecting things. After I removed the harness I noticed the photo I took while under the car showed one of the black plugs disconnected. I likely, not thinking, disconnected it prior to taking the photo but I couldn't actually remember, so I was just double checking what would happen if it was disconnected the whole time, which I now know wasn't the case based on the above info. Thanks again for your input on the matter!