Brake Fluid Pressure Sensor

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robsis35
Posts: 14
Joined: Thu Feb 26, 2015 8:56 pm
Car: 2006 Infiniti M35

Brake Fluid Pressure Sensor

Postby robsis35 » Wed Apr 07, 2021 7:54 am

I have a 2006 Infiniti M35 2WD and i got the ABS actuator and electrical unit replaced. I still am getting ABS warning lights and when i put an OBD scanner on it, it is giving me the C1142 brake pressure sensor which i can't find in the engine. Is this component part of the ABS unit? Maybe internally because i really cant find a picture or anything for this piece. Any advice is appreciated.


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VStar650CL
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Car: 2013 Altima 2.5 SL, 2004 Altima 2.5 S

Re: Brake Fluid Pressure Sensor

Postby VStar650CL » Wed Apr 07, 2021 8:30 am

I can look up your specific ride later, but most N/I brake pressure sensors are in or on the master cylinder.

robsis35
Posts: 14
Joined: Thu Feb 26, 2015 8:56 pm
Car: 2006 Infiniti M35

Re: Brake Fluid Pressure Sensor

Postby robsis35 » Wed Apr 07, 2021 9:26 am

I can see there is a connector on the master cylinder but i thought that was the fluid level sensor, not the brake fluid pressure sensor. I thought they are two different things.

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VStar650CL
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Car: 2013 Altima 2.5 SL, 2004 Altima 2.5 S

Re: Brake Fluid Pressure Sensor

Postby VStar650CL » Wed Apr 07, 2021 10:19 am

The level sensor will be in the side of the reservoir, not the cylinder body.

robsis35
Posts: 14
Joined: Thu Feb 26, 2015 8:56 pm
Car: 2006 Infiniti M35

Re: Brake Fluid Pressure Sensor

Postby robsis35 » Wed Apr 07, 2021 11:17 am

Ok i follow that. So is the brake fluid pressure sensor a different component? And if if is where is is located? Within the ABS actuator?

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VStar650CL
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Car: 2013 Altima 2.5 SL, 2004 Altima 2.5 S

Re: Brake Fluid Pressure Sensor

Postby VStar650CL » Wed Apr 07, 2021 11:55 am

I just pulled your ride up in ASIST and it looks like the pressure sensor is built into the ABS. However, it also looks like the C1142 represents a conflict between the brake pedal switch and the pressure sensor (the latter sees pressure but the brake switch shows un-pressed). So the most likely problem is bad adjustment of the brake pedal switch or a "soft spot" in the pedal switch contacts. This seems to be analogous to the P0705 on Versas being caused by moisture in the taillamps but the TCM incorrectly blames the Range Switch. In this case, the most likely culprit is the pedal switch contacts but the ABS incorrectly blames the pressure sensor. Try a new pedal switch!

robsis35
Posts: 14
Joined: Thu Feb 26, 2015 8:56 pm
Car: 2006 Infiniti M35

Re: Brake Fluid Pressure Sensor

Postby robsis35 » Wed Apr 07, 2021 12:45 pm

Ok sounds good. I will look into the pedal switch and see what turns up. Thanks for the input!

robsis35
Posts: 14
Joined: Thu Feb 26, 2015 8:56 pm
Car: 2006 Infiniti M35

Re: Brake Fluid Pressure Sensor

Postby robsis35 » Wed Apr 07, 2021 3:33 pm

Checked the brake switch and it is working fine. I pulled it out and checked continuity by pressing and then releasing the push button on it and it had continuity. Also put it into the brake pedal and had someone press the brake while i checked continuity and it was fine. Now does that mean the switch is working correctly all the time and it could be intermitten, dont know.

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VStar650CL
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Car: 2013 Altima 2.5 SL, 2004 Altima 2.5 S

Re: Brake Fluid Pressure Sensor

Postby VStar650CL » Wed Apr 07, 2021 4:23 pm

robsis35 wrote:
Wed Apr 07, 2021 3:33 pm
Checked the brake switch and it is working fine. I pulled it out and checked continuity by pressing and then releasing the push button on it and it had continuity. Also put it into the brake pedal and had someone press the brake while i checked continuity and it was fine. Now does that mean the switch is working correctly all the time and it could be intermitten, dont know.
Don't trust it. N/I brake switches are a) notorious for "soft spots" in the switch plating, and b) the ABS and brake lamps are very likely working off two different throws, which will cause issues if the throws lose synchronicity because of soft spots. Remember, the ABS lives in the digital domain and "thinks" much faster than you and me. Small flaws in sensors or switches that we think are fine might cause 100 microseconds of unresolvable confusion for the 8-bit critter living inside your brakes, with consequent codes and grief for the human occupant, you. Just replace it.

robsis35
Posts: 14
Joined: Thu Feb 26, 2015 8:56 pm
Car: 2006 Infiniti M35

Re: Brake Fluid Pressure Sensor

Postby robsis35 » Wed Apr 07, 2021 4:26 pm

Ok i will. I will let you know what happens. Thanks!

robsis35
Posts: 14
Joined: Thu Feb 26, 2015 8:56 pm
Car: 2006 Infiniti M35

Re: Brake Fluid Pressure Sensor

Postby robsis35 » Mon Apr 12, 2021 12:24 pm

Ok replaced the switch. Ran for about 50 miles so far and no new warning lights.

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VStar650CL
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Car: 2013 Altima 2.5 SL, 2004 Altima 2.5 S

Re: Brake Fluid Pressure Sensor

Postby VStar650CL » Mon Apr 12, 2021 2:26 pm

:bigthumb:


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