hi guys, my cc is not working, what would be the first port of call.

 

Rich

 

 

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You definitely sure that it has it? The switch could be faulty or a blown fuse.

You definitely sure that it has it? The switch could be faulty or a blown fuse.

 

My thoughts too....

 

....I assume there must be a relay as well; probably something simple like that!

 

Richard:cool:

Switch is okay and lights up the cruise control switch on the dash, i'll look for the fuse and check it out.

 

Thanks

 

rich

watch that the cut out microswitch under the brake pedal is not set too sensitive otherwise it won't work

Easy way to check the adjustment of the switches Put your foot under the brake pedal and pull it up towards you then try the cruise If its a manual then its more likely to be the switch on the clutch pedal - do the same test for this

Thanks Ted, got your diag as well, mines an auto but i'll try it anyway

 

Rich

You definitely sure that it has it? The switch could be faulty or a blown fuse.

 

Simon, when you say the switch , which switch are you referring to?

Simon, when you say the switch , which switch are you referring to?

 

 

Here you go:

 

 

 

Jeff TT

There are 2 micro switches on the back of the auto brake pedal, one is the brake light switch, the other the CC cancel switch. If the CC cancel switch has failed it will act as if your always on the pedal and stop the CC latching for obvious reasons, although the brake lights won't be on because that's the other switch.

On a manual car, there is yet another switch on the clutch pedal which cancels the CC when the clutch pedal is pressed.

With my first Z, my CC had failed, it was the switch on the brake pedal that had broke inside. Cost about £35 from a main dealer surprisingly.

Simon, when you say the switch , which switch are you referring to?

 

 

Pedal switch. But the others have cover that too.

Going back to my cruise control problem again...

 

Guy, if it is NOT the button on the brake pedal, and NOT the relay, is there any other culprit you can think of?

 

Rich

Where is the relay out of curiosity?

yer ill like to know that not yet tested my peddal switches but would like to know were the relay is as mine didnt work as well. but all the lights come on the dash when i switched it on so cheers.

SD hi, sorry for the gap, if you haven't found out, Japanese for (air con) - I mean CC is I think ASCD, im not sure about a relay but the fuse is in the kick panel in the drivers footwell, 3 Down 5 Across. see picture

 

Regards

 

rich

Edited July 23, 201411 yr by Rev1Richie

More info, Right, with my CC not working, I have checked the micro switch on the brake/acc (auto) , checked fuse, and have now replaced the unit from the cable end to the oval switch. it still doesn't work, so is there Anything else I haven't looked at/swapped out to make it work?

 

Cheers

 

Rich

Edited July 22, 201411 yr by Rev1Richie

At what speed did you try to use the cruise control?

At what speed did you try to use the cruise control?

There is a my experience has shown that the vacuum pump is the issue (located in the engine bay). There is a test you can do in the service manual in which you run a chapter in the manual designated to Cruise function and Diagnostics. Diagnostic tests use a 12V supply (wire from the battery) to various terminals on the pump plug- simulating cruise actuation etc. The pump creates vacuum, so a leak in the diaphragm or pump failure etc will result in non- functioning cruise.

 

... or it could be as simple as the small 6mm vacuum hose has come off that links the pump to the diaphragm

 

Another point to note that to ensure the cable that connects to your throttle body linkage is adjusted correctly (reasonably firm). This will result in much smoother CC operation

sorry, that didn't read too well, and cant find post edit function on this forum :(

ACSD is cruise, not AC.

Don't worry about it, got the gist of it.

 

Thanks for replying, not often I hear from our antipodean cousins

 

Rich

At what speed did you try to use the cruise control?

 

Graham, all speeds mate, I know that CC don't work up to certain speeds, which makes me think, what trips this speed to allow the cc to work, maybe that's broke?

 

rich

Found this answer on a site (aus300zx) which I will be looking at ... well impressed

 

Sorry, I may have got the description of which light lights up in the wrong order. The circuit diagram says teh "Crusie Cont" light comes on when teh crusie control is turned on, and the "Crusie" light comes on when the crusie speed is set. In any case, if you're at all handy with a multimeter, get to the ASCD control unit next to the ECU, and with the ignition on and the cruise control turned on, and the auto in drive if an auto, check the voltages on pins 5 and 11.

 

Pin 11 should have zero volts on it, and when you press the brake pedal, you should see 12 volts.

 

Pin 5 should have 12 volts on it, which should drop to zero volts when the clutch pedal is pressed in, or the auto selector is moved to neutral, or the cancel switch is pressed. The ASCD computer will not allow a speed to be set unless there is 12 volts on pin 5. If you don't have 12 volts on pin 5 with ign and ASCD on, but your cruise control light still comes on, then the fault will be an ASCD hold relay (the brown one in the passenger side footwell, from memory), or the neutral and parking position relay (auto shifter), brake or clutch switches.

 

Sometimes the pedal switches move out of alignment and don't close properly, and sometimes if the brake pedal is slightly loose at the top of its travel, it can bounce around while driving, and cancel the cruise as well.

 

It's also possible that your steering wheel is at fault. There are three slip ring connectors on the back of the wheel. If any aren't making contact, then your ASCD and/or horn won't work.

 

Oh, and you can't set it below 48 KPH or thereabouts in any case.

ACSD is cruise, not AC.

 

sorted

Guys, thought id let you know, I found another part of the ASCD circuit that no one mentioned, so just to let you know there is a control unit under the passenger footwell near the main ECU and the Gearbox one. I was going to check the pin voltages, but when I looked under the carpet, the bleeding thing wasn't even plugged in!!!. so I popped the plug in and whey!! hey!! a working cruise control... If only someone knew about it sooner and told me.

 

Rich

That would be too obvious mate :lol: