DIY: Test Neutral and Reverse Switch
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Grasshopper
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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.
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:
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.
a) White connector = neutral switch
b) Black connector = reverse switch
3) Remove both connectors for switch to be tested.b) Black connector = reverse switch
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:
a) For the neutral switch, the readout should display numbers.
Doesn't matter how much resistance you read, the inductive sensor just needs to "see" something.

b) For the reverse switch, the readout should be "open" or no numbers displayed.

6) Now put the shifter into gear:Doesn't matter how much resistance you read, the inductive sensor just needs to "see" something.

b) For the reverse switch, the readout should be "open" or no numbers displayed.

a) For the neutral switch, you can shift into any gear
b) For the reverse switch, you need to put it into reverse
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).
b) For the reverse switch, you need to put it into reverse
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?
Thread Starter
Grasshopper
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From: Streetsboro, OH

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??
...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??
Thread Starter
Grasshopper
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From: Streetsboro, OH
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
I honestly didn't know that... learned something new...

I know... being picky...
Though seeing as I've never been further west than Ohio (where I live), that shows you how I am with traveling

I honestly didn't know that... learned something new...
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.
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:
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.
a) White connector = neutral switch
b) Black connector = reverse switch
3) Remove both connectors for switch to be tested.b) Black connector = reverse switch
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:
a) For the neutral switch, the readout should display numbers.
Doesn't matter how much resistance you read, the inductive sensor just needs to "see" something.
Attachment 158704
b) For the reverse switch, the readout should be "open" or no numbers displayed.
Attachment 158706
6) Now put the shifter into gear:Doesn't matter how much resistance you read, the inductive sensor just needs to "see" something.
Attachment 158704
b) For the reverse switch, the readout should be "open" or no numbers displayed.
Attachment 158706
a) For the neutral switch, you can shift into any gear
b) For the reverse switch, you need to put it into reverse
7) Observe the multimeter's display:b) For the reverse switch, you need to put it into reverse
a) For the neutral switch, the readout should be "open" or no numbers displayed.
Attachment 158705
b) For the reverse switch, the readout should display numbers.
Attachment 158707
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).Attachment 158705
b) For the reverse switch, the readout should display numbers.
Attachment 158707
Thread Starter
Grasshopper
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From: Streetsboro, OH
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
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
Thread Starter
Grasshopper
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From: Streetsboro, OH
Comments like this could prevent people from helping you and welcomes argumentative members to crap all over this thread.
Thread Starter
Grasshopper
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From: Streetsboro, OH
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
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...
Now, how hard is it to replace the reverse switch?
Edit: Turns out it was pretty easy...
Last edited by toddkrein; May 27, 2014 at 03:19 PM. Reason: update
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.
Thread Starter
Grasshopper
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From: Streetsboro, OH
***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

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

New on left vs Old on right

***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.***
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

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

New on left vs Old on right

***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.***
Last edited by xAgyex; Sep 8, 2015 at 02:28 PM.
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)
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)
Last edited by mrpablozone; Sep 15, 2015 at 02:36 AM.
I bought a 26mm socket and cut a slit up the side of it. Worked great.




