Guys,

I really really need your help.

I am a happy owner of a 2003 Infiniti g35 sedan. It has 182,000 miles but still going strong.

Recently I started experiencing some braking problems.

First of let me say that the car was parked for the past 3 months because I needed some CAMSHAFT sensors (as you all may know it needs ORIGINAL Nissan sensors and I could not locate these in my area).

I finally ordered and replaced the sensors and the car started.

The BIG problem I am having now is that sometimes when I am accelerating (from 0 MPH to like 15MPH at a stop light or after a speed bump) sometimes the brakes engage automatically!

When this happens, the SLIP light blinks. After the brakes engage a few times and the entire car shakes, the VDC OFF, and slip lights come on and stay on.

After these lights stay on, the automatic braking no longer occurs and the car drives fine.

If I turn off the car, the lights go off and when I turn it back on, the same braking problem occurs when I am accelerating (It does not happen all the time but only sometimes).

I tried scanning the car but I got a totally different error code (O2 sensor) totally not related to this braking problem.

PLEASE HELP!!!

This ia serious problem because I think I might be involved in a traffic accident if I don't fix it soon. I love my G35 but this is a serious problem and I don't know what is happening.

Thanks Guys!

Greetings from Belize,

METALLIDETH (Gustavo)

 

Sounds like the ABS wheel speed sensors are causing issues. Seems they may be detecting slip when there is no and activating the brakes.

Are your tires sizes different front and rear?

You may want to inspect the 4 wheel speed sensors for debris, rust, damage, etc.

If you were to unplug a wheel speed sensor, it would fault the ABS system and the issue should stop...however you won't have ABS or traction control...but at least you can accelerate.

ABS codes are stored differently than the engine codes, so scanning for engine codes won't reveal anything. however, until the ABS light goes on, not much can be done in terms of code scanning.


a lot of times, guys who put two different wheel sizes on front and rear complain about this issue.

 

Yes,

I have different size tires. Do you really think this could be the problem?

For example in the back I have 225 60 r17 on both and in the front I have 225 50 r17 and on the other tire in the front I have 225 65 r 17. Would this really cause the problem?

Also, where are the ABS wheel speed sensors?

Wow, I don't know bout sounds strange.

Also, If I unplug the ABS relay or VDC relay located under the hood by the battery, will this help??

Thanks my friend!!!!

 

"front I have 225 50 r17 and on the other tire in the front I have 225 65 r 17"


Maybe you could get away from front and rear being slightly different. However, having two difference sizes in the front is def. going to cause some problems.

The wheels sensors are monitored by the car to see how fast each of the wheels are turning. All four should be turning and showing the same speed. If the car sees a different speed for any of them it may think that you have lost traction. I may apply the brakes for you. And if the speed reading continues to be off the system may completely shut down and give your the light on the dash.



For the front wheels sensors, take of the wheel and look in on the other side of the rotor. There is going to be a wire with bolt on it. That is where the wheels sensors are.

As far as unplugging the ABS VDC relays, that may help with problem. but will probably give you other lights, codes and symptoms.

 

Your differing tires sizes are the problem. You are confusing the ABS system as it only allows up to 3% difference.

That one 225/50/17 is off by 10%. You need to replace it with proper size tire

 

Yep. Unfortunately these work off of sizing so you need to have correct sizes!