ASR - Acceleration Slip Regulation
A few days ago I noticed the ASR
warning light coming on (only the warning, not the Hazard triangle
light). After lot of reading, I tested a few things.
- After starting the engine the ASR is off.
- After a few minutes of driving ASR light comes on.
- If I manage to drive without braking (hand brake and luck...), the ASR wont come on.
- When I start using the brake, after a few brakes, the light comes upon "releasing" the brake.
I also tested this, without moving the car. After starting the car,
keeping the hand break take the car our of P, and press the brake pedal
a few times.
In a few tests, I noticed that the ASR comes on no matter if the gear is in P or D.
I didn't see any issues with the break light.
This made me think that since the car was not moving, likely it was not the speed sensor (hall effect sensor).
I also looked at the ASR circuit diagrams and concluded that the Brake Light Switch might be causing the problem.
So, next step was to go down in that tight spot, and take out the switch.
It is a very small space, running out of air, up side down, ... not fun.
To open up the pannels, .. you need to take off 2 screws.
One screw is here:
The second one is here:
The black plastic trim is also connected in two other places, .. so be gentle not to break it.
A long plastic tab is in the carpet, here:
And the side panel is connected to the black cover, here:
And finnally it is out:
The brake light switch is way up, on top of the brake pedal:
It has a release tab, and then easily twists off. Then you need to remove the 2 connectors. Be carefull with the locking tabs of the plastic connectors..... and finnally the switch is out !
I checked the switch (double switch - one normal, and one inverted) with a DMM. The large pins control the brake lights, and the small pins go to ASR system. As expected, the ASR switch was intermittent.
So I replaced it, put everything back and it is all good to go.
The switch was ~$28 CAD (love the Canadian price! It was double in the US).