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The stop lamps on your vehicle are controlled (turned on by the BCM ) - body control module ,turn signal lamps as well . Your vehicle doesn't have a normal brake light switch ,has a low voltage sensor , not to say they can't go bad .
Turn Signal Lamps
The body control module (BCM) is responsible for controlling the turn signals and hazard lamps. When the turn signal switch is placed in either the left turn or right turn position, the BCM receives a signal from the turn signal switch. The BCM then sends an on-off voltage signal to either the left or right turn signals and their instrument panel cluster (IPC) indicator. When the hazard switch is pressed, the BCM receives a signal from the hazard switch. The BCM then will send an on-off voltage signal to all the turn signal lamps. All the turn signal lamps will flash including both IPC turn signal indicators.
Stop Lamps
The body control module (BCM) is responsible for controlling the stop lamps. When the driver presses the brake pedal, the BCM will receive a signal from the brake pedal position sensor. The BCM then supplies battery positive voltage to both left and right stop lamp assemblies and to the center high mounted stop lamp (CHMSL). The stop lamps are grounded at G401 and G403. The CHMSL is grounded at G302.
The first step in the diagnostic process should always be to check for DTC'S - diagnostic trouble code's ,an follow a service diagnostic trouble chart ,testing electrical circuit's .Not listen to someone say it's the brake switch , because in most case's he has no ideal what he's talking about . I have 30 year's GM experience , the level of electronic's on your vehicle , most people just don't have a clue . Your best bet ,take it to a qualified repair shop . That doesn't mean the dealer either . A lot of good independent repair shop's out there .
Do you know how to test using a DVOM - digital volt ohm meter ? Is there B+ voltage going into the brake light switch ? An coming out when the brake pedal is pressed ? What fuse's ? There is only one fuse for the brake lights !
The BRAKE SW fuse in the RH I/P fuse block supplies battery positive voltage to the normally-open stop lamp switch. When you press the brake pedal the switch contacts close and battery positive voltage is supplied to the left and right stop lamp assemblies and to the center high mounted stop lamp (CHMSL). The left and right stop lamp along with the CHMSL are grounded at G302.
Do you know about the right insturment panel fuse box ?
Stop Lamps Inoperative
Step
Action
Yes
No
Schematic Reference: Exterior Lights Schematics
1
Did you perform the Lighting System Diagnostic System Check?
YES - Go to Step 2
NO - Go to Diagnostic System Check - Lighting Systems
2
Press the brake pedal.
Do all of the stop lamps illuminate?
YES - Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
NO - Go to Step 3
3
Are all the stop lamps inoperative?
YES - Go to Step 4
NO - Go to Step 7
4
Inspect the BRK SW fuse.
Is the fuse open?
YES - Go to Step 14
NO - Go to Step 5
5
Disconnect the stop lamp switch.
Using a test lamp connected to ground, probe the battery supply voltage circuit of the stop lamp switch connector.
Does the test lamp illuminate?
YES - Go to Step 6
NO - Go to Step 13
6
Install a fused jumper between the battery supply voltage circuit and the stop lamp switch signal circuit of the stop lamp switch connector.
Do the stop lamps illuminate?
YES - Go to Step 12
NO - Go to Step 17
7
Determine if the center high mounted stop lamp is inoperative or the stop/turn lamps are inoperative.
Are the stop/turn lamps inoperative?
YES - Go to Step 8
NO - Go to Step 9
8
Do the turn lamps operate normally?
YES - Go to Step 17
NO - Go to Turn Signal Lamps and/or Indicators Inoperative
9
Disconnect the center high mounted stop lamp.
Using a test lamp connected to ground, probe the stop lamp switch signal circuit of the center high mounted stop lamp at the harness connector.
Press the brake pedal.
Does the test lamp illuminate?
YES - Go to Step 10
NO - Go to Step 15
10
Using a test lamp, probe between the stop lamp switch signal circuit and the ground circuit of the center high mounted stop lamp with a test lamp.
Press the brake pedal.
Does the test lamp illuminate?
Go to Step 11
Go to Step 16
11
Inspect for poor connections at the harness connector of the center high mounted stop lamp. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 20
Go to Step 19
12
Inspect for poor connections at the harness connector of the stop lamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 20
Go to Step 18
13
Repair a open or high resistance in the battery supply voltage circuit of the stop lamp switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you complete the repair?
Go to Step 20
--
14
Repair a short to ground in one of the following circuits:
• The battery supply voltage circuit of the stop lamp switch
• The stop lamp switch signal circuit of the stop lamp switch
Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you complete the repair?
Go to Step 20
--
15
Repair a open or high resistance in the stop lamp switch signal circuit of the center high mounted stop lamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you complete the repair?
Go to Step 20
--
16
Repair an open or high resistance in the ground circuit of the center high mounted stop lamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you complete the repair?
Go to Step 20
--
17
Repair an open or high resistance in the stop lamp switch signal circuit of the stop lamp switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you complete the repair?
Go to Step 20
--
18
Verify the stop lamp switch adjustment. Refer to Stop Lamp Switch Adjustment . If OK, replace the stop lamp switch. Refer to Stop Lamp Switch Replacement .
Did you complete the repair?
Go to Step 20
--
19
Replace the center high mounted stop lamps. Refer to High Mount Stop Lamp Replacement .
Did you complete the repair?
Go to Step 20
--
20
Operate the system in order to verify the repair.
Did you correct the condition?
System OK
Go to Step 2
well let's see is it only one side or both sides ? this could be a blown fuse/s there could be blown out bulbs on one side or both or the brake light pedal switch has shorted out or a ground wire for the lights has come off this has a lighting control module in it if you change anything that's it but check other things listed first before you spend$$$ do not change the computer this has nothing to do with the lights go to the lighting control module and unplug it clean the connector put some conductive grease on it and plug it back in corrosion on the contacts can be stopping the electrical current transfer through the plug to the unit DO NOT CHANGE THE ECM/COMPUTER THIS IS NOT INVOLED IN THE LIGHTS /SIGNALS/BRAKE LIGHTS THIS IS ENGINE MANAGEMENT ONLY POST BACK WITH RESULTS AND WE WILL TAKE IT FROM THERE IF THE PROBLEM PERSIST STEPHEN
hole in brake line and possible need new brakes put mre fluid in and have someone looking under the car while you step on the brake peddle should be able to see where it is leaking right a way
I myself like to gravity bleed brakes, open all of the stop-cocks, and keep adding brake fluid, make sure you are on level ground after about 2o minutes you should be good to go
One of 2 things to have checked, if all your bulbs and connections are correct. 1-stop lamp switch module. 2-multifunction/combination switch (blinker arm/components that are in the steering column). For about a 1/2 hrs. labor cost, a mechanic should be able to test the circuits.
No, it is not anything to do with the gas. Most likely cause is a vaccum leak look at your brake booster. open the hood look at the fire wall right in front of where you sit. The brake booster will have a hose comming out of it going to the engine this hose is loose or has a hole in it. when you step on the brake it **** air causing the engine to trun off sometimes.
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