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Hello, my 2009 Pontiac g8 Gt has a red brake light indicator ongoing on the cluster and in the DIC window that stays on constantly and removing the battery and re attaching it back after several days is not removing it.

I have tested to make sure the sensor is actually working with a multimeter. I manually pressed the float down in the master cylinder and checked that the sensor's circuit closes when that happens. What is weird is that checking the voltage coming off either wire when the float is being pressed down or is fully down does not change at all, it stays straight at 5v, which I think is a little weird if the sensor's circuit closes only when its down.

I also checked the voltage individually coming off of each wire. When checking from the Brown/White side wire through the multimeter to a separate ground, I got 5v.When checking from the Black side wire through the multimeter to a separate ground, I got 5v too. This tells me there's no connection problems in the wire.

I attached the schematic that another user posted a while back if that will help anyone.

My question is can the code and brake light warning be held on by the cluster?
Also does anyone know if the code is self canceling or if I am required to have it cleared by a tech 2 scanner?
Any suggestions on what the problem could be?
Thanks
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Hello, my 2009 Pontiac g8 Gt has a red brake light indicator ongoing on the cluster and in the DIC window that stays on constantly and removing the battery and re attaching it back after several days is not removing it....My question is can the code and brake light warning be held on by the cluster? Also does anyone know if the code is self canceling or if I am required to have it cleared by a tech 2 scanner? Any suggestions on what the problem could be?...
The anti-lock brake system module operates the brakes and the instrument cluster merely displays information received from various components. Not 100% positive the code is self-canceling although would think disconnecting the battery for about thirty minutes or so "should" do the trick. Brake warning light.
 

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I had to do some testing on my low level switch/sensor due to what appears to be misleading info in the service manual. I just had to know which way was which. I took the connector off, an with the level of fluid in my reservoir ( I think a little down from max). I read across the 2 pins of the switch/sensor with the meter, an I got a resistance reading of 156 ohms. I then depressed the float down to simulate a low/empty reservoir, an the meter reading went to infinity on the scale I was using (might have been a very high resistance value if I had selected a higher setting), but whatever. I turned the ignition on (with that connector removed) I got the brake warning messages as you did. Checked the voltage on the brown striped wire an got 4.3 volts to the ground stud at the drivers side fender. Checking the black wire to the same ground point (knowing that it must read zero or very close to that), i got a reading of zero ohms. I reconnected the low level switch/sensor connector, turned on the ignition an the warning lights cancelled themselves. That means (at least in my car), low resistance is what you have to have to keep the warning lights out. A high resistance or a resistance above a certain amount, is going to trigger the logic circuit to turn those warning lights on.

If your connector was attached to the switch/sensor, the ignition on, an you back pinned that connector an found the voltage on the black wire ( to an alternate ground source), that makes me think that the black wire is actually open vs going to ground as it must. I'm pretty sure the circuit is designed to illuminate the warning lights when the resistance goes high/open. Whenever the black wire (which must be grounded at all times) develops an open condition, I think you are guarantied to get that brake warning light

Just to make sure I didn't fool myself, I'll do this again under better conditions at a later date. If anything changes, I'll post up info as required.
 
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