Brakes crunch and pedal vibrates when braking

[NorwegianPathfinder]

I've had problems with the left, front ABS sensor and hence changed it twice.
Fault lights turn on at random (abs, esp off, slippery road and 4wd), but they turn off when I stop and start the engine again.
The brakes crunch, as if the abs is depoyed, when I brake but the braking effect does not seem to be decreased.
Also, when deployed, the cruise control seems to contribute to the fault on the brakes (the fault comes more often). And the engine/transmission jerks - especially when I drive downhill with the cruise control on.
Sound familiar to anyone? Or any advice to what I could do?

[VStar650CL]

Is the wheel bearing okay? A bad bearing will definitely make the ABS misbehave and could contribute to a pulsation issue.

[NorwegianPathfinder]

I haven't checked the wheel bearings, but I'll definitely do that.
I still wonder if there might be any connection between the cruise control and ABS fault, or if they are two separate problems altogether.

[VStar650CL]

I can't think of any reason CC would exacerbate a wheel sensor falsing, but it may just be the way you work the throttle compared to the way the CC does. Throttling up and down will definitely affect orientation and behavior of a loose wheel bearing.

[NorwegianPathfinder]

Could a worn tie rod result in a similar fault? I noticed that both front wheels had some play in the horizontal direction and it seems to come from the tie rods.

[Niti QX4]

If you have bad tie rods, then they need to be replaced as well. Wheel bearings need to be greased and checked when rotors are replaced. If the bearing preload is not done correctly, you will end up with bad bearings. Did you take the wheels off and spin the rotors to listen to the bearings?

[NorwegianPathfinder]

I see. I'll look into getting the tie rods either repaired or replaced.
I haven't checked the sound from the bearings - there is however a scrunching sound coming from that area, that I took to come from the brakes. But on second thought it just might come from the bearings.
Great advices coming in here - I appreciate it a lot.

[NorwegianPathfinder]

I've changed both tie rods, that were pretty worn, checked and cleaned all four ABS sensors and rings, checked the wheelbearings, which seem to be ok and checked all ABS fuses, but still no sign of improvement.
Any suggestions to what else could cause the unwanted ABS activation and subsequent deactivation?

[VStar650CL]

I think you'll have to get an ABS-capable scanner on the car and watch the system in realtime. At this point, without knowing what the ABS brain is seeing and thinking, you're shooting blind.

[NorwegianPathfinder]

That sounds like a good idea - I've been thinking of buying a scanner and now would be a good time.
Any recommendation of a particular scanner for Pathfinder that is within a reasonable price range?

[VStar650CL]

They tell me the ABS-capable Foxwells are good and don't cost a ton. There are also PC-based apps like Giotto that you can buy a Nissan package for, those will handle just about every Nissan system and are almost as good as a Consult3+. Obviously I use the C3+ at the shop, so I'm not really the right guy to ask.

[NorwegianPathfinder]

It seems like I can't reply any further, but I'll give it a last try:
Thank you for the recommendation - it gives me something to work with.
Any opinion on icarsoft scanners in general and the model cr pro in particular?

[VStar650CL]

It seems like I can't reply any further, but I'll give it a last try:
Thank you for the recommendation - it gives me something to work with.
Any opinion on icarsoft scanners in general and the model cr pro in particular?

I haven't used it, but it looks like a knockoff of the bottom-end Snap-On Solus. I'd check with iCarsoft and make sure it will stream all the ABS parameters you'll need to look at, wheel sensors, actuator status, SAS and G-sensor. If it will do that then I'd say the price is right and it's a good choice.

[NorwegianPathfinder]

I just found out that my left cv axle appears to be in bad shape and in need of replacement. The left tie rod, that I replaced, was also pretty dilapidated on the outermost joint especially. Might be a connection there, I presume.
Does anyone know if a bad cv axle can cause the ABS system to malfunction? I have significant vibrations in the car; especially when I let go of the throttle from high speed and let it roll downhill. But there are continuous vibrations at any speed - even though they're not that significant but mostly just unpleasant and noisy.

[VStar650CL]

If the wheel bearings are healthy then a bad CV should have no effect on the ABS sensor (nor should tie-rods, unless they're so severely out that they make the wheel squirm instead of rolling. I personally have never seen that).

[NorwegianPathfinder]

It was just brought to my attention that the propeller shaft is worn down at the u-joint. This is the source of the vibrations.
I had a mechanic look at it and he said that the ABS system can indeed fail when the prop-shaft is loose, as mine is.
Any thoughts on that? Is it likely that the ABS activates and then shuts down due to a loose prop-shaft?

[VStar650CL]

I don't know what your DCi has for an ABS system. If it's a 3-point setup (separate front, conjoined rear) then the rear sensor is on the input to the rear diff and driveshaft problems can affect it. If it's 4-wheel independent then it can't, because the sensors are in the wheels.

[NorwegianPathfinder]

It's been a while now, but I can end this thread by informing that I fixed the problem completely simply by seating the ABS sensors on the rear axle firmly in place with zip ties. Presumably due to corrosion they were just a little bit out of place. A scanner was helpful in finding out excactly where I had to look.