2006 SRX Cadillac Problem,, "Weird"

[cubsfan1953]

Guys, I was told by mechanic that I had a bad Brake Pedal Sensor.
This is not like the old brake switches. It is like a Potentiometer. I replaced this sensor.
Did not correct issue. Issue I'm having is Brake lights are on all the time that ignition switch is on.
I have three lights on dash on. ABS, Brake, And Traction Control.
I don't have the right software to get into the Brakes and ABS System .
I have several different Scanning Interface's but none will get where I need to get,
I believe that ScanXL GM Addon will do this.
If someone knows where I might find this addon I sure appreciate the help,,
Thanks in advance.

cubs

[clusters]

How did the mechanic diagnose it? Did he verify the 5V reference to the sensor and sensor ground then do a bypass test to check the wiring integrity? If not he wasted your time.

If you used anything but an ACDelco sensor straight from GM you wasted your money.

ScanXL will not help you. You need an uplevel scantool, and the new sensor has to be calibrated. Autel Maxisys or Snap-On will do the job.

Good luck.

Edit: Looking a little further into the wiring, if the high mount light is staying on then the problem could by anywhere from the sensor to the EBCM, a stuck BASS relay or any of the wiring. If the high mount light is not on, it could be the turn signal/hazard module.

[cubsfan1953]

All the lights including the high mount light are staying on. Will look at some of the wiring tomorrow,,
But I still think I have a Speed Sensor bad. Replaced the Back Drivers Side Hub Bearing and sensor today.
No help tho.

cubs

[clusters]

Speed sensor has nothing to do with it.

Try swapping the BASS relay under the left rear seat with another one and see if the lights go out. That's about all you can do.

Without a scantool, you are guessing and wasting time and money. That's the only way to diagnose this properly.

[cubsfan1953]

Speed sensor has nothing to do with it.

Try swapping the BASS relay under the left rear seat with another one and see if the lights go out. That's about all you can do.

Without a scantool, you are guessing and wasting time and money. That's the only way to diagnose this properly.



Thanks brother I will look for this relay,,

cubs

[cubsfan1953]

Today I pulled the Bass Relay that you stated,, and Checked it and it works as it should,
It has two contacts, one normally open, one normally closed, Energizing the coil and one makes and the other brakes as they should,
So what ever is causing the brakes to be on has this relay activated when ever the ignition switch is on,,
With the relay out, The brake lights are all off as they should be. Gonna try and find a schematic for this thing,,

cubs

[clusters]

The BASS relay is triggered by the EBCM according to inputs from the pedal sensor.

What happens if you leave the pedal sensor disconnected?

In the diagram below you see the sensor connected to the EBCM and the orange trigger wire coming out that energizes the BASS relay (not shown in pic because of screen size). The connections to the ECM and TCM on the orange wire are just inputs to those modules.

[cubsfan1953]

Clusters,, I will pull the plug of the Brake Pedal Sensor tomorrow. And see if they go off.
Thank You for schematic,
cubs,

[cubsfan1953]

With the Brake sensor unplugged the brake lights are still on clusters.
Ok went to start car and move it a few feet with sensor out it will not come
out of park, So undoubtedly the sensor is doing something in that area.

cubs

[cubsfan1953]

I bought a Tech2 scanner,, When telling the Brake Pedal Position Sensor to recalibrate the brake lights go out.
Then you turn off the ignition switch and back on and the brake lights are on again.. I ordered an new EBCM. Should be here in a few days.

Cubs

[Meat-Head]

SUMMARY:-

brake pedal switch is pot, which needs setting up with
$2000 of computer , the bcm sends an analogue on or off signal
to a relay invented by the Victorians in 1890.

oh the corrugated cardboard box the new part came in was also invented around the same time.