So I know there are a bunch of threads on this but the majority of them say the cause for the lights on is needing new brakes. Had new front and rear brakes a little under 10k miles ago and replaced the rear parking brake.

The lights come on occasionally when I hit the brakes on the highway and then go off for a couple of days once I restart the car. I haven't checked the brake fluid level, but is there anything else like a speed sensor or something like that I should be worried about?

Its a 2005 G35x with 100k miles.

Thanks!

 

Brake fluid is the easiest thing to check.... so do that first.

Next best thing to do is take it to a mechanic that you know well and has one of those computer reader/scanner thingies you can plug right underneath the steering wheel.

I had this same problem about 2 months ago ('05 g35x - 93,000km)
The scanner let me know it was the front passenger side speed sensor
Changed it ($260 CDN including parts and labour) and it began working fine.

Is your AWD light on as well? Mine was.

 

ABS sensor perhaps. Check your ABS light by turning the key to the "ON" position but not starting the car, this will illuminate ALL your bulbs temporarily, if the ABS doesn't light up, then your bulb is burnt out and you have a bad sensor.

 

I agree with TunerMax.
First get it scanned somewhere so you can pick up a code. Then look up the code online or google it.
I had this problem in Jan 2012, scanned the car and a code popped up for front driver side ABS sensor. Checked the sensor and found out the wire somehow got torn up. Bought a new sensor, installed it, and drove a couple miles and no more abs/vdc/slip lights.
Good luck to you bro.

 

Mine was the front right sensor wasn't connected. EZ fix for me.

 

-.- pop the hood and look at the brake fluid level..



- Eric
626-592-3103

 

Agreed with the brake fluid.

 

Had the same issue. At first the lights would come and go. They would always go away when I restarted the car. However, for the last month or so, they light up right away after I start the car.

I checked everything I could. When I hooked up my computer I got a code: C1142 - Pressure Sensor System. Not sure that is actually the problem.

I do remember when the car was new I had a similar problem and the dealer replaced the Brake Switch Assy. I ordered that switch and will try that first.

BTW, when I start my car and put enough pressure on the brake pedal do disengage that brake switch (doesn't take much, just little pressure) , the lights DON'T turn on at all. As soon as I let go on the brake, they lights light up right away.

It could be that brake switch.
I should have the new switch in my hand before the weekend and will try to replace it.

 

Just an update..

New brake switch installed and still have the same problem.

Well, based on the code pulled, it could be the pressure sensor. Too bad that on the G35, the pressure sensor is the whole ABS pump system as defined by the service manual.

After reading all the procedures about troubleshooting this, the service manual advised one needs to replace the whole ABS pump (VDC actuator) to fix this issue.

I have been looking at the damn thing and there is actually a bosch pressure sensor sticking out of the unit. It appears that a lot of cars use the same exact pressure sensor and it costs about $120 ...........

Why is there no mentioning of this specific sensor in the service manual? It only talks about the whole system including the ABS pump.

The question I guess would be, if the car is complaining about the pressure sensor could I just replace this one bosch sensor and start there instead of replacing the whole abs unit?

http://www.finjector.com/verkkokaupp...0265005303.pdf
http://www.mksautobusiness.fi/custom/0265005303.jpg

 

In case anyone here cares, I was finally able to fix the problem.
After checking everything I could based on the service manual, it looked like I would need to replace the ABS pump/pressure sensor/actuator.

When I put the car back together last night and the G35 was still getting the three lights and still getting a code C1142 in the computer I was pissed.

I turned the car on , and the lights are there. Out of frustration I pumped the brake pedal very quickly about 15-20 times. After I restarted the car the lights were done.
Drove the car to check if the VDC worked and it it did. Also tried to brake hard to check ABS and they did work as well. This morning everything is still working right. 30 miles commute to work and everything is still working.

 

lol..... interesting.
congrats none the less! i know how frustrating such problems can be

 

Two days later and about 150 miles driven, I don't have the famous ABS VDC off, SLIP light yet.

Everything is working ............So after almost 2 months driving with these lights, pumping the brake hard around 20 fixed the issue.

 

Wow, you're lucky! I had to replace my front driver side abs sensor. Good luck!

 

According to the service manual these lights can come up if any of these things are not working,:

any of the 4 wheel speed sensors (aka ABS sensor)
low brake fluid
Yaw Rate / Side G Sensor
Stop Light Switch
Steering angle sensor
and a few others:

If my case I check all sensor and they were okay.
The computer code was error C1142 pressure sensor circuit.

Therefore, pumping the brakes hard may have helped fix the problem.
For many others here with the same lights this may not work.

You need to read the error code from the computer and start there.

I have seen many people here complain about the ABS slip and VDC off lights coming up but very few if anyone said that they read the code from the computer and what that code was.

 

no lights for almost 3 years.


A few weeks ago, got the light again and code c1142 pressure sensor.