RED BRAKE LIGHT WARNING CHIMES

[Petnatcar]

Hi Guys,

Anybody know how to disconnect the chimes when the Red Brake Light comes on?

The brakes work fine and I've replaced the Fluid Level Sensor in the Brake Fluid Reservoir but
the light and chimes still pop on.
Haven't checked the Hand Brake Switch yet but that's next, I just want to stop the noise from the chimes.

Thanks,
Peter

 

[TJBaker57]

Hi Guys,

Anybody know how to disconnect the chimes when the Red Brake Light comes on?

The brakes work fine and I've replaced the Fluid Level Sensor in the Brake Fluid Reservoir but
the light and chimes still pop on.
Haven't checked the Hand Brake Switch yet but that's next, I just want to stop the noise from the chimes.

Thanks,
Peter

Best way is to find the trouble and fix that.

The chimes sound as a result of a serial data message sent by a control module that has sensed a fault. The chimes are a function of either the factory radio or an aftermarket audio system that supports the chimes function. No simple way to stop it. I suppose you could disconnect your radio or all the speakers!

 

[Petnatcar]

Best way is to find the trouble and fix that.

The chimes sound as a result of a serial data message sent by a control module that has sensed a fault. The chimes are a function of either the factory radio or an aftermarket audio system that supports the chimes function. No simple way to stop it. I suppose you could disconnect your radio or all the speakers!

What do you think I'm trying to do?
There's lots of theories out there but nobody ever pinpoints the problem.
I also have the dim drivers headlight and the engine quits when I turn on the high beams.
Can I pull the fuse for the radio or do I have to unplug it from the harness?

Thanks for your help.

 

[TollKeeper]

Because of the way the system integrates, for when no key is on, and the chimes are still working (headlight reminder for example), you actually have to unplug the radio, as there are 4 total power splices for the radio system.

Next we need to talk about your specific problem, what codes you have scanned in that system, what you have replaced, etc.

The biggy is getting your system scanned with a ABS scanner. Although I own 2 scanners that can scan ABS systems, I am no where near you.

 

[TJBaker57]

The brakes work fine and I've replaced the Fluid Level Sensor in the Brake Fluid Reservoir but
the light and chimes still pop on.
Haven't checked the Hand Brake Switch yet

Were these replaced after reading the code that details why the red warning light is on? Or were these just shots in the dark?

If the warning light is on then there is a DTC in one module or another for WHY that light is on.

If the scanner used to check for the code doesn't find it when the warning light is on then that scanner is not the right scanner.

There's lots of theories out there but nobody ever pinpoints the problem.

Nobody out here has your truck in front of them so they can do the proper diagnostics. Anything else is just one guess after another.

Can I pull the fuse for the radio or do I have to unplug it from the harness?

Not certain but that would be a place to start. The thing I am ot certain of is of the truck has the premium sound with an amp then it might need to have the amp fuse pulled. Again, I am uncertain. I know this much,,, the chimes come from the sound system so to kill them you need to kill off the sound system.

also have the dim drivers headlight and the engine quits when I turn on the high beams.

Hmmm... Maybe a poor ground that is common to the high beams and an engine control system? Need to check on that...

 

[TJBaker57]

biggy is getting your system scanned with a ABS scanner. Although I own 2 scanners that can scan ABS systems, I am no where near you.

A bluetooth dongle ($15) and the right smartphone app can do this. "Car Gauge Pro" is one such app.

For the tech-savvy it can be done first-hand with a serial terminal app. All one needs is the dongle and the ability to follow directions from someone who knows how.

 

[Petnatcar]

Okay, that sounds good.
Pretty sure my shop can do the ABS Scan. What'll that tell me?
The ABS light has been on for the last 7 years but the brakes work fine...?

I have NO CODES and No Engine Light...?

I changed the Fluid Level Sensor in the reservoir but not the Handbrake Switch...yet.

I've cleaned all of the ground contacts that I can see and lubricated with Dielectic Grease.

So I don't really know what to do next.

Were these replaced after reading the code that details why the red warning light is on? Or were these just shots in the dark?

If the warning light is on then there is a DTC in one module or another for WHY that light is on.
The light comes on and off and seems to go on when I turn Right...?
If the scanner used to check for the code doesn't find it when the warning light is on then that scanner is not the right scanner.

I only have a simple code reader



Nobody out here has your truck in front of them so they can do the proper diagnostics. Anything else is just one guess after another.




Not certain but that would be a place to start. The thing I am ot certain of is of the truck has the premium sound with an amp then it might need to have the amp fuse pulled. Again, I am uncertain. I know this much,,, the chimes come from the sound system so to kill them you need to kill off the sound system.
All righty then. I never listen to the radio anyways so I can disconnect that.




Hmmm... Maybe a poor ground that is common to the high beams and an engine control system? Need to check on that...

ENGINE CONTROL SYSTEM ? I don't like the sound of that.
What is that?
Thanks,
Peter
PS Thi is my other car.
I built this thing but I'm lost on vehicles with computers.

 

[TJBaker57]

Hmmm... Maybe a poor ground that is common to the high beams and an engine control system? Need to check on that...

So maybe check out ground point G107 on the left side of the engine. Seems the left headlamp and the fuel pump relay use this same ground. There can be times when a ground is OK for low power loads buy fail under higher power demands,,,, like a high beam draws. Just a theory mind you.....

 

[TJBaker57]

I have NO CODES and No Engine Light...?

You do have at least one code or your ABS and brake warnings would not be on. Let me explain. The usual run of the mill scanner only talks to the engine computer. They most often do not even ASK for codes from the BCM (Body Control Module), or the EBCM (Electronic Brake Control Module), or the HVAC Module, or the Liftgate Module and on and on.

 

[TJBaker57]

The ABS light has been on for the last 7 years but the brakes work fine...

There is a ground point for the ABS system that is very frequently all rusted up. It is on the frame underneath the truck under the driver seat. You can see it from the underside of the vehicle. If this ground is for sh** your brakes will still work but your Antilock Brake System (ABS) will not work as it should. AND it will set an ABS code that will turn on the ABS light.

 

[TJBaker57]

Pretty sure my shop can do the ABS Scan. What'll that tell me?

If you have someone else do the scan ask them to write down or print out the results. What you want is the alpha-numeric code, not a verbal description if what it may or may not mean.

Here are just some of the codes that are available. You can see they are pretty specific about where there is some trouble....



If that frame ground underneath the drivers seat area is poor you will very likely have a bunch of codes stored including things like "loss of communication" since the brake control computer gets its ground from that point.

 

[TollKeeper]

Are we getting ahead of ourselves?

You said in your first post that the RED brake light is on. Is your YELLOW ABS light on too?

Depending on your year of truck, you would also possibly get a Stabilitrac Light across the message screen on the speedo.

If the yellow light isnt on, you might not even have a code stored in the ABS System, at least thats my understandings..

EDIT: My quick search indicates that if the RED Brake light is on, its either a switch (Parking Brake, Low Fluid), or a Hydraulic Failure. But this was a quick and dirty search, so I could be wrong.

 

[Petnatcar]

That's almost too much information.
The RED BRAKE LIGHT comes on NOW and THEN.
We only want to disable those stupid chimes at this point.
So I'm gonna disconnect the radio and the amplifier.

I unhooked one wire from the driver side speaker but that didn't stop the chimes?

The ABS light has been on for 7 years, SEVEN YEARS, but the brakes work fine !!!

Ground point 107 might be for the 5.3 engine (lower left center of engine block)
but my grounds are clean on the engine (see pic).

I cleaned both grounds under the driver side like in your photo then drilled new holes and used 5/16" self tappers with dielelectric grease, no pics of those.

 

[Petnatcar]

Can I tap into the common black ground wire near the head lights and run another ground someplace solid?

 

[TollKeeper]

You dont have to disconnect the amplifier, Should only have to unplug the radio.

That being said, the ABS light will have a stored code, but that stored code can only be read by a diagnostic tool designed for it. The ones at Autozone/Advance/etc cant read them.

With the RED Brake light coming on and off, I would start with your initial thought process first, and pull the boot up on the hand brake, and see if you can unplug the parking brake switch. See if that turns off the RED Brake light.

If that doesnt work, then look at pulling the 2 wire looms at the radio.

 

[Petnatcar]

I just realized the shop did the ABS scan last year and I need $800 worth of stuff to fix it.
I never drive at night anymore or in the winter so as long the brakes prevent me from running into something I'll be okay. I don't need the ABS plus I'm extra cautious when I drive.

 

[Petnatcar]

Okay that sounds good.
I'll get back to you tomorrow with some results.
Thanks again for all the tips.

Peter

 

[Mooseman]

IIRC, if there's a complete failure of the EBCM, it has no power or there is no communication from it, the BCM will also turn on the brake warning light. That could be happening if it has a bad ground. Notwithstanding the original problem with the ABS, this could be a secondary failure. However, I don't think the BCM would command the radio to play the chimes.

I do know for a fact that if you have the parking brake on and you put it in drive, or while driving you pull the parking brake, the chime will sound. I think that's your problem.

 

[TJBaker57]

don't think the BCM would command the radio to play the chimes.

So the parking brake switch is not connected to the EBCM in any way. The park brake switch is connected only to the BCM on the flat ribbon cable, connector 3 terminal A4. The BCM knows where you have shifted as the PCM reads the shift range position switch and broadcasts a serial data message about where the shifter currently is. So in the end the BCM must play some role in the sounding of the chimes at least as far as the park brake switch is concerned.

Here about a year ago I play around sounding my chimes just learning how....

 

[TJBaker57]

This one at least does not look good to me. That is a lot of green corrosion on that cable at least and the bolt looks pretty rusted. I have experienced cable connections that "looked" fine but when tested with meter proved to be not connected at all! Caused an intermittent no-crank situation in my case.

 

[Mooseman]

I meant to say that if it's the EBCM that's at fault that the BCM would not command the chimes however it would for the parking brake.

 

[Petnatcar]

This one at least does not look good to me. That is a lot of green corrosion on that cable at least and the bolt looks pretty rusted. I have experienced cable connections that "looked" fine but when tested with meter proved to be not connected at all! Caused an intermittent no-crank situation in my case.

View attachment 106798

Okay, I'll take that apart and clean those connections.
I've been meaning to check the resistance on that cable???

I guess because it didn't have corrosion oozing out between the bolt and the block that it was okay.
Is this a case where "looks can be deceiving"?

Do you advise on using Dielectric Grease on reassembly?

Thanks,
Peter

 

[TJBaker57]

In my particular 2002 LT with Bose it is indeed the amplifier that responds to the chimes message from my BCM. The "40" preceding the partially highlighted chimes command is the BCM address and the "81" preceeding the same chimes message is the amp. The radio would have been "80".

Okay, I'll take that apart and clean those connections.
I've been meaning to check the resistance on that cable???

I guess because it didn't have corrosion oozing out between the bolt and the block that it was okay.
Is this a case where "looks can be deceiving"?

Do you advise on using Dielectric Grease on reassembly?

Thanks,
Peter

Dielectric grease can surely help but it is important to know a few things. For one it is not a conductor so it is not a great idea to put 'in' a connection. It is used to help seal up a connection that is already in good clean standing. Its' use is to prevent exposure to the elements that indroduce corrosion. It cannot make a bad connection better.

Looks most definitely can be deceiving in relation to electrical connections. The issue I spoke of earlier in my Trailblazer was an intermittent no crank. I eventually found a connection on the starter that "looked" perfect. With a meter I tested and had power on the cable eyelet, power on the nut that secured it, power on the washer beneath the nut, but no power on the stud that everything was secured to!! All it took was a practically invisible buildup of oxidation inside the connected components.

Now that particular connection of yours with the green corrosion I would not think is a direct cause of any of the issues your are having because it at least looks to me to be not the G107 I suspected to be an issue but instead that looks like the main ground from the battery judging by the cable size. Regardless, it would be a good idea to freshen that up as well as any others nearby.

 

[budwich]

with all the effort that has been done already, not sure why one wouldn't address the most obvious and ensure that the e brake switch is either replaced or checked electrically. Maybe even just unplug it and see what happens. Go from the result.

 

[TJBaker57]

For the benefit of those with a bluetooth dongle and know what to do with this (from an 02 GMT360, no key in ignition. Bit 7 is windshield wipers, I see bits 0 & 1 high when key is in run position)...

 

[Petnatcar]

with all the effort that has been done already, not sure why one wouldn't address the most obvious and ensure that the e brake switch is either replaced or checked electrically. Maybe even just unplug it and see what happens. Go from the result.

Budwich,
That's exactly what I plan to do.
Just waiting for some warm weather in NNY. No heat in the garage but I'll keep you posted.
Thanks.

 

[Petnatcar]

For the benefit of those with a bluetooth dongle and know what to do with this (from an 02 GMT360, no key in ignition. Bit 7 is windshield wipers, I see bits 0 & 1 high when key is in run position)...

View attachment 106810

TJ,
I don't understand the computer codes but I appreciate your insight.

 

[Petnatcar]

This connector is under the armrest on the Handbrake side.
I was hoping to reach the Handbrake Switch through here but it doesn't look to good.
Would it be connected to one of those Brown, Orange or Yellow wires?

 

[Petnatcar]

Is this the Handbrake Switch???
It looks more like a ground contact.
It is a copper spring type contact against the edge of that flange and it has a good strong contact.
There is only a single Light Blue wire attached to it.
Unplugging that will only leave the circuit open and make the chimes ring won't it?
Now what?

 

[Mooseman]

Yep, that's the one. It grounds when the brake is applied. Pulling that connector will disable it and theoretically fix your problem unless that wire is shorted to ground elsewhere.

 

[Petnatcar]

Thanks Moose.
I'll see what happens next.

 

[TJBaker57]

TJ,
I don't understand the computer codes but I appreciate your insight.

What it means is that with a bluetooth OBD adapter and a custom PID in Torque Pro or equivalent it is possible to confirm the proper operation of the park brake switch without ever touching a tool.

 

[Petnatcar]

TJ,

Yep, that's the one. It grounds when the brake is applied. Pulling that connector will disable it and theoretically fix your problem unless that wire is shorted to ground elsewhere.

No effect disconnecting that little switch.
It rings worse then ever.

 

[TJBaker57]

So I'm gonna disconnect the radio and the amplifier.

So have you done this yet and the chimes stopped? (just need to pull fuse(s).

 

[Petnatcar]

Not yet but I will.
I'll keep you posted.

 

[budwich]

TJ,


No effect disconnecting that little switch.
It rings worse then ever.

BUT.... that's good. Although people indicated that disconnecting the switch would stop the issue, they ASSUMED that the switch is a normally open switch that goes closed when the brake is pulled. It would appear that is untrue. It appears to be a normally closed switch. Thus, you need to run a fused wire to a known good ground and connect it into the connector that was removed from the switch. Go from the result.

of course, the best thing would be to test the switch to see what it actually is... normally open or normally closed.

 

[TJBaker57]

course, the best thing would be to test the switch to see what it actually is... normally open or normally closed.

This looks pretty convincing right here. Normally open.

 

[TollKeeper]

If the plug on the E-Brake is just 2 wire (Which I think it is), you could always test that by jumping the 2 terminals. No fuse needed.

 

[Mooseman]

It's just one wire/terminal. The switch grounds at the bolt.

Like I was saying, that wire may be grounded somewhere else. Check to see if there is continuity to ground from that wire. If not, then we can move on.

 

[TollKeeper]

@Mooseman - My apologies.. As usual, you are correct. Self grounding switching...