300zx cruise control not working

• Forum Listing
• Marketplace
• Advanced Search
• Discussion Forums
• 84-89 Tech Discussion Forum

Cruise control 86 300zx

• Add to quote

I really need help and can not find the right answers online to this simple question. My cruise control does not work but I think it has to do with the buttons on the steering wheel. How do I take the cover off? I do not want to break anything on my car. Please help  

Chances are a plastic stopper for the cruise disable switch/s for the brake and/or clutch have disintegrated. Do the audio controls work? However if you must pull the switches off, the attached diagram may help. The horn pad just peels off.  

Attachments

Here is a URL for the plastic plug/stopper issue: http://www.xenonzcar.com/z31/Brakelampsstuck.html OEM replacement plugs are readily available, but almost any plastic or rubber plug that remains secure in the hole seems to work just fine. Just remember to adjust the switches with a 1 mm gap between plunger and plug when disengaged.  

this is a common problem on the 300z. just follow the guide given above and you should be able to remove. if the problem is not in the button controls or the pedal plastic stopper grommets, then you may have a vacuum issue or problem with the cruise control unit itself (in the engine bay). my 87 has this same issue and I am trying to fix it as well... I think its the pedal grommet stoppers that have come off. btw, if you notice that your brake lights are remaining on after you shut down - this is caused by the same problem as the cruise, only the plastic grommets are for the brake system... with them gone, the lights will stay on. check both of these while you are at it down in there and have fun... it's always fun to be tangled up under the dash on a Z31:grin there is a cruise control troubleshooting write-up over at www.xenonz31.com that has some good info on fixing issues with the cc. Bonny Bon  

Bonfire79, Please update your links. xenonz31.com will be going away and all content has been moved to xenonzcar.com  

Had a issue with my cruise. The green light would come on but turn off when I started to drive. I took off the steering wheel and cleaned the contacts and pads on trigger wheel. My cruise is working again.  

Just figured you'd like to know that I found the clutch pedal was missing the plastic stop that's supposed to contact the clutch switch on my 1985 300zx so I made one up and placed it in the brackets hole. The odometer had also stopped recording the mileage and I didn't even know it. While I was under the dashboard I tapped on the odometer case with the back of my screwdriver and took it for a test ride. The cruise control AND odometer work perfectly. I hope this helps you.  

• ?            
• 95.6K members

Top Contributors this Month

Log in or Sign up

You are using an out of date browser. It may not display this or other websites correctly. You should upgrade or use an alternative browser .

cruise control problem

Discussion in ' Technical ' started by boof , Jan 31, 2010 .

boof New Member

could anyone help me with some info I have a non turbo 2+2 anyway when you hit the cruise button on the dash the cruse light lights up and thats it nothing happens all the bits are all contected up the bonnet and looks fine have tried swapping the steering wheel controls with another set I have in shed but didnt do anything Any Ideas or direction to go in would be of great help  

K-zed Secret Squirrel

Check the fuse is ok and relay is in place. Diagnostics as per FSM in tech section.  

thanks will give that a go  

pexzed Forum Administrator

The Side pod controls near the instrument cluster is the Master "On/Off" for the cruise control only. Once you have activated this cruise control "on/off" function on the side pod (turns a green light on on the instrument cluster), then you need to set the speed using the steering wheel buttons. Sorry if you are already trying this, but you only mention the dashboard, and that is just the basic Master "on/off" controls. For standard (unmodified) cruise controls, they only function between 48kmph and 105 kmph. (You can still activate the master On/Off switch, but the steering wheel controls only work between those designated speeds.  

Kabir Well-Known Member

Your Cruise control unit may be isn't getting speed signal from cluster. I had similar issue and spent hours to dig the problem. Is your power steering working OK after 10 sec starting the car?  

the master is turning the light on on the dash but when you hit the steering wheel buttons nothing happens  

power steering is working fine no probs with it thanks  

kurtcash New Member

hi there i have the very same problem, please help  

SPOOLE300ZX New Member

Me to, iv had the same problem for about 6 months, it just stoped working. dash lights still come on but when i hit the set button nothing happens!!!  

Brock32 Active Member

Try pulling the center horn cover off and check that the buttons are connected. When i picked my car up the guy said the cruise didn't work and this was why.  

Red Dwarf Long term Zed Owner

The cruise control has speed restrictor on it at 110kmh above that it wont cut in, so if you are below that speed maybe the speed sensor is not working properly perhaps ?  

Cove Getting to be an old fart

turn on the ignition so all idiot lights are on, can start car if you wish but not necessary. Leave the car running or ignition on, get out of car and check the brake lights are off, if the brake lights are on then a plastic button has broken between the switch and the brake pedal and cruise control will not work with brake lights on ( it is a cut out for when the cruise is engaged )  

aazn New Member

with this problem your best bet is going for a new unit.. i work with autron units (OEM product) i install over 10 a week.. and have never had a fault with them. if anyone wants one installed let me know and i can hook you up for a good price.  

gday I tried a different steering wheel and wheel controls  

kawasakirider New Member

I'm having the same issue. My cruise used to work fine but I tried using it on Wednesday night and it won't work. If I hit the on button on the dash pod, the green light in the dash comes on, but when I hit the set/coast buttons, nothing takes over. I've tried it at various speeds and stuff, nothing works. I took the horn pad off just then and everything is connected. What fuses should I be checking? Any help would be appreciated, Cheers!  

Mikezah build thread incoming!

you have to take the whole steering wheel apart and clean the contact pad that the buttons (and their contact brushes) make contact with. I had the same issue as all of you guys are having. by using a multimeter I found that I was not receiving continuity from the wheel to the wires further down the steering column. ive found that the grease over time builds up and gets dust/dirt in there somehow and the brushes no longer make suffienecnt contact for the cruise buttons to work. however in my case my horn didnt work either which is also a sign haha. EDIT : its not the wheels problem its where the wheel mounts which is the problem  

Dangerous Member

It's been a long while since I played with Zed ASCD's, so this is going from memory. If the "cruise cont" light comes on when you push the cruise on/off button, that's a good start. This means that your main ASCD fuse is OK, and your ASCD hold relay is working. Next check that your horn works, as the steering wheel switches get their power from the horn relay. The speedo should be working too, as it sends speed pulses to the ASCD computer. Actually, that's not quite true. The speed sensor in the gearbox has to work, and the signal has to get through the speedo to the ASCD - the speedo itself can actually fail, but the ASCD will still work if it's getting the speed pulses. If the "CRUISE" light does not come on when you press the steering wheel button, it is most probably the brake (or clutch if the car is a manual) ASCD switches. The cruise control computer has to see battery voltage on pin five before it will allow a speed to be set. The battery voltage gets to it via the main ASCD fuse, then through the ASCD hold relay (brown relay in the left side footwell area), then through the clutch switch or the auto neutral and parking position relay (the auto must be in a drive gear at least), then through the cancel switch on the brake pedal, then on to pin 5 of the ASCD computer. Most of the time, I've found it's that the brake or clutch pedal or the ASCD switches that are attached to them need adjustment. Note that both pedals have two switches on them. The two on the brake are for the brake light and the ASCD cancel switch, and the two on the clutch if a manual are for the ECU to see when the clutch is pushed in (ever wonder why the engine revs rise slightly when the clutch is pushed in?) and the ASCD cancel. The two pedal ASCD switches are normally open, ie the brake and clutch pedals have to be fully 'up' for the switch to close and to allow current to pass through. The ASCD cancel switches are the ones with the blue plug on them, and the ones on the brake pedal and clutch pedals are exactly the same switch, so they are interchangeable. Both need to be working though. A simple test is to drive on a straight road above 48 kph, turn the cruise control on and making sure that there's no traffic or obstructions around, put your foot under the brake pedal (and for the second test, the clutch), and pull it up firmly with your foot and hold it there. Then try to set the cruise control. If the cruise sets, but drops out as soon as you release the pedal, then it's just switch adjustment, which is quite simple, but a bit hard to get to. The switches are right up near the tops of the pedals, and they hit and close on a small green plastic pad (sometimes these pads fall out too, which can be a culprit) attached to a bracket on the pedal. The switches are screwed into place, with a lock nut to hold them in place. To adjust them, loosen the lock nut, take out the plug, screw the switch further in until it closes with the pedal in its resting position, tighten the nut and reattach the plug. If the switches look OK, grab a multimeter (and someone who knows how to use them if you don't) and monitor the voltage on pin five of the ASCD computer (located under the ECU). With the ignition on, in gear and cruise main switch ON, you should see 12 volts. Any one of turning the main switch off, pushing in the brake or clutch pedal slightly, or shifting the auto sshifter out of drive should make the 12 volts disappear. If all this works OK, then either try a loan ASCD computer in place of yours (they are pretty reliable), or pull the steering wheel off as suggested and check it and the cruise buttons - they are also pretty reliable. Also try a loan ASCD pump (the bit in the engine bay). If you can't get 12 volts at pin 5 no matter what you do, then this is still in all likelihood your problem. Go through all of the fuses and pedal switches and if it's an auto, also the shifter inhibitor switch and the neutral/park position relay. You should be able to trace 12 volts all the way from the main ASCD fuse towards pin 5. Once you lose 12 volts, you've found the cause of the fault. Oh, and series 2 Zeds have a different ASCD computer and wiring on the ASCD pump, so don't try to compare things directly. The pump itself is common, but the wiring to it isn't. Hope that helps. Cruise on a Zed is a must have option :zlove: Just a word of warning though - DON'T under any circumstances permanently short out any switches or permanently apply any voltages to get the cruise to work. It's complicated because it has to be a failsafe system. Don't compromise this safety.  

Nauraushaun New Member

Please clarify what happens when you hit set/coast on the steering wheel. Does the dash light come on, signifying that the car should be cruising? Or does nothing happen at all?  

when you press the crusie button on the side pod. the crusie light comes on, then when you are travelling at a high enough speed you press the cruise button on the steering wheel and another cruise cont (i think) light comes on next to the current one on the dash. so once you have pressed the 2 buttons there should be 2 buttons lit up on the dash. keep in mind as stated above that if the brake switch or clutch switch is trigged at all, the light wont come on  

Other way around, Mikezah. When you press the cruise on/off button on the right hand pod, the "Cruise Cont" light should come on. If it does, then this usually mans that your main ASCD (Auto Speed Control Device) fuse and ASCD hold relay are OK. Then when you press the set button on the steering wheel, the "Cruise" light should come on and the cruise speed should be set. The "Cruise" light is controlled by the ASCD computer. If the "Cruise Cont" light comes on when you hit the pod switch, but the "Cruise" light doesn't come on, then in order of likelihood, I'd be looking at pedal switches, horn fuse, inhibitor switch and neutral/park relay if an auto, ASCD control unit, and speedo (speedo supplies the speed pulses to the ASCD computer). Speedo obviously jumps to the top of the list if it's playing up. As per previous post, if the ASCD control unit doesn't have 12 volts on pin 5 (green wire with red stripe), it will never allow a speed to be set. Kawasakirider, I'd be checking this first in your case, by the sound of it. If the Cruise Cont and the Cruise lights come on but the car doesn't cruise at the set speed, then I'd be looking at the ASCD pump in the engine bay, then checking that the ASCD copmputer plug is securely fitted. Check that the small vacuum pipe is still intact. Easiest way to check it is to try a known working unit from someone else's car. Hope this helps everyone.  

Share This Page

• Log in with Facebook
• No, create an account now.
• Yes, my password is:
• Forgot your password?
• Search titles only

Separate names with a comma.

• Search this thread only
• Display results as threads

Useful Searches

• Recent Posts

Z31 Cruise Control Troubleshooting

Sources used on this page:.

• 1984-1988 Nissan 300ZX Factory Service Manual

Model Navigation

• General Discussions - 300ZX Related

• Remember me Not recommended on shared computers

Forgot your password?

Cruise Control??

By redwine300 October 16, 2011 in General Discussions - 300ZX Related

• Reply to this topic
• Start new topic

Recommended Posts

Not really used Cruise Control much,:blush:

I have tried it once or twice but not sure if it is working correctly.:wacko:

Could someone explain the fundamental workings please and how to operate them?

I imagined that when travelling at say 80MPH I would press the "Set Coast" button and the cruising speed would then be set? When I try this the speed drops away as soon as I lift my foot. The only way I can seem to set the cruising speed is by repeatedly pressing the same button.

As for the other buttons????

Link to comment

Share on other sites.

Cruise control only works within certain speeds. For Jap imports it wont work above about 75mph

Cheers Yowser,

As mine is a UK Model would there also be a working range?

Also, what about the other buttons?

I can assume what the cancel one means.:wacko:

Guest Mrs HollowPoint

Mine doesnt seem to want to know anything above 55 which sucks a bit

I just haven't got it. Not fair :sad:

uk working range is much larger, cant remember exactly but something like above 30mph , and i'm sure mine used to work up to at least 90mph

turn on cruise control with switch on right pod, light should come on on dash

pressing set will set the cruise speed, resume accel will accelerate whilst you press it but you will drop down to set speed when you release unless you press set again at the new speed.

pressing the clutch or brake pedal will also cancel the cruise. a good place to start on a faulty cruise control is the switches under teh pedals are set correctly.

[sIGPIC][/sIGPIC]

Thanks Guys and girls,

So in summary, say I am doing 80 mph and I hit the "Set Coast" then the speed will be controlled at that speed until I hit the brake/clutch pedal.

As for the "Resume Accel" button, I use this (press and hold) if I want to add speed but is only active whilst I hold the button depressed?

I am not sure mine behaves this way, I will hopefully try again soon.

Thanks so far,

Thanks Guys and girls, So in summary, say I am doing 80 mph and I hit the "Set Coast" then the speed will be controlled at that speed until I hit the brake/clutch pedal. As for the "Resume Accel" button, I use this (press and hold) if I want to add speed but is only active whilst I hold the button depressed? I am not sure mine behaves this way, I will hopefully try again soon. Thanks so far, Redwine300

Yes, providing your Activating the Cruise control, on the side pod first.

You can also hit the cancel button on the steering wheel to switch off cruise, then hit the resume button again and it will speed up/slow down to the previously set cruise speed and hold it again.

9 years i had a zed with cruise control, which i used a lot , and i never new that

Yes, then hit the resume button again and it will speed up/slow down to the previously set cruise speed and hold it again.

iain knight

My JDM 1990 TT works fine from 40-70mph, there is a mod you can do to expanded the range which I think you can go from 30mph to 100+mph by removing some resistors in the cruise control ecu box.

Thanks again everyone, :thumbup:

Can't wait to go and have a play, now that I know what I'm doing.:blushing:

Weather permitting, I will do some tests at various speeds and try and find out the minimum/maximum operating speeds.

Watch this space.

• 2 weeks later...

Well I finally got a chance to try my cruise control today.:)

Firstly, I can set cruise at 30mph (minimum) and so far up to 80mph. (will hopefully get a chance to try for higher soon)

One thing I did notice that I had not seen before, When I activated the cruise control on the right hand side pod, the far left GREEN cruise control light lit on the dash, (nothing new there)

This is the new bit, when I hit the "set cost" button on the steering wheel, a second GREEN light lit up next to it (Cruise) and hey presto, I was in cruise.

OK so far so good, (had not seen this before):excl:

Next I tried the cancel and resume buttons on the steering wheel, sure enough cancel gave me back control and resume picked up the cruise speed again. (I think I need to remember to lift my right foot when returning to cruise mind as there seems to be a varying delay)

Now the bit I am not to sure of, I set the cruise at 70mph and everything was great, at this point I tried the resume accel button, if I hold it in the speed increases constantly and if I press it repeatedly, the speed goes up in small steps. The only thing I am unsure of here is the fact that it does not return to the original cruise speed. (70mph)

I have come to the conclusion that this button has dual purpose, Resume = return to last set speed and eccel= add speed to set speed.

Anyway, that the story so far, I hope to try above 80mph tomorrow.

Well I finally got a chance to try my cruise control today.:) Firstly, I can set cruise at 30mph (minimum) and so far up to 80mph. (will hopefully get a chance to try for higher soon) One thing I did notice that I had not seen before, When I activated the cruise control on the right hand side pod, the far left GREEN cruise control light lit on the dash, (nothing new there) This is the new bit, when I hit the "set cost" button on the steering wheel, a second GREEN light lit up next to it (Cruise) and hey presto, I was in cruise. OK so far so good, (had not seen this before):excl: Next I tried the cancel and resume buttons on the steering wheel, sure enough cancel gave me back control and resume picked up the cruise speed again. (I think I need to remember to lift my right foot when returning to cruise mind as there seems to be a varying delay) Now the bit I am not to sure of, I set the cruise at 70mph and everything was great, at this point I tried the resume accel button, if I hold it in the speed increases constantly and if I press it repeatedly, the speed goes up in small steps. The only thing I am unsure of here is the fact that it does not return to the original cruise speed. (70mph) I have come to the conclusion that this button has dual purpose, Resume = return to last set speed and eccel= add speed to set speed. Anyway, that the story so far, I hope to try above 80mph tomorrow.

No it won't return to the original 70 mph, you are actually pressing the ACC button which increases your speed, as you say, keep hold and it will carry on accelerating constantly, press repeatedly and it will speed up a bit at a time, the resume switch can be used when you have used the coast button to slow down for some reason, let's say roadworks, when you come out of the roadworks, hitting resume should take you back to the cruising speed before the slow down, also, if you have touched your brakes and cruise has cancelled, you can then press resume and it will resume the last speed before you hit the brakes. Hope this makes sense....lol:lol::lol:

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

×   Pasted as rich text.    Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.    Display as a link instead

×   Your previous content has been restored.    Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

• Insert image from URL
• Submit Reply

Recently Browsing    0 members

• No registered users viewing this page.
• Existing user? Sign In
• Acceptable Usage Policy
• Club Constitution
• Privacy Policy
• Meet the Team
• Online Users
• Online Users (logged)
• Member List
• Member List (Premium)
• Leaderboard

Latest Competitions

• All Activity
• Content (latest)
• Content (unread)

My Activity Streams

• Latest Content
• Subscriptions
• Classifieds
• Create New...

Important Information

Terms of Use