Question about cruise control on 370z
 

My cruise control doesn't work and I brought it to a mechanic. He said the culprit is a bad crankshaft position sensor. I was Googling the correlation between the crank position sensor and the cruise control and I couldn't find anything.

Anyone else got their cruise control fixed by replacing the crankshaft position sensor?

Do you have any mods done to the car? Mine didn't work a few months ago but I realized I had to adjust the RJM clutch pedal I installed.

Hello Brancky3,

no modifications to the car. I have an automatic transmission. Is there a correlation between the crank position sensor and the cruise control module?

Do you have a CEL? If not then there is most likely nothing wrong with the crank position sensor. Also some history (conditions when problem started, any recent maintenance, etc.) might help.

Most common cause of loss of CC is the brake or clutch pedal switch. AFAIK, the CPS has nothing to do with CC. Diagnostics, adjustment procedures, wiring diagrams, &c are in the FSM.

First thing, you need a new mechanic. Your current one is clueless. :owned:

If the CPS was bad, your car would not start. The crank sensor sends a signal to the ignition module so the module can send a signal to the coils to fire. No crank signal, no spark. Period.

Like others have said, the common reason of CC to quit working is brake switch or clutch switch (for those that have MT).

Please don't be like the people I see at the parts store that buy a crap load of fuses to replace all their fuses when something doesn't work...... :ugh2:

This.. when your CPS fails, its detrimental to the car, its not just your cruise failing. :iagree:

Here is a drawing of the two switches that I threw together when my clutch pedal switch staring failing...the upper one is the one for the cruise control, the other is for the clutch pedal to start the car. Hope this helps.

Such nice helpful people on this forum. *tear*

No CEL. Thanks.

Thank you

Thanks

Cost to repair is $700.

The mechanic misdiagnosed the problem and told me it was the brake switch.

So my cruise control has become intermittent now again. 1 1/2 years ago I was having the problem of the cruise sometimes engaging / disengaging and I took it into the dealership (still under warranty).

When I got it back, was told they had to replace some switch.

Well it has started up again and now I am not under warranty.

Same symptoms as before:

1) Green light comes on, but cruise does not set when button pushed.
2) Lift up the brake pedal with foot and I can engage cruise.
3) If I hit a bump or rough patch of road, cruise disengages.

So looking at the pictures that mults posted above, it seems like I need to make an adjustment to the UPPER SWITCH (I have an Automatic). I assume that I need to adjust nut 3 to move the switch such that it is a little bit lower in order to touch the plate on the brake pedal. It would seem that I would want to make slight adjustments, because you still want the cruise to disengage when the brake pedal is pushed.

I looked into this when I first had the problem, but since it was under warranty took it into the dealership. I asked the Tech when I picked up the car if they had to make an adjustment to the switch, but he said "Oh no, we had to replace it". I am hoping that was just dealership mentality of lets replace a part with a new part instead of just making an adjustment to a perfectly good part.

There are some people who have taken the switches apart completely to clean the contacts. It worked just fine after that. But I don't think any of the brake or clutch switches cost more than $20, so it may or may not be worth the effort of repairing them. They are very easy to replace.

A little quick research -- looks like the Part Number is 25300-62J0E. Price looks to be around $35. Looks like it is a part number that is used in a couple of other locations (clutch) as well.

I will pull my current one out and give it a quick go over -- maybe the switch pin got a little gummy and a squirt of WD-40 will do the trick. If not, $35 is small change.

Thanks for the insight. I think it is better to repair/replace the switch than to adjust the nut to compensate for a part that may be beginning to fail.