I finished installing the calipers on my car after have them powder coated and started her up for a test drive. The anti lock brake and automatic brake differential light is aluminated on the dash. Everything appears to be installed correctly in regards to the quick disconnects on the brake wiring at the wheel hubs. I never cycled the ignition (turn the car on) during the month long process until the car was put back together. Would the brakes throw codes when the ignition was off and I unpluged brake sensors etc.? The battery in my 993 is approx. 6 months old and I have read the lights could be caused by a low battery. The car did sit for about a month without a charger but it is a bit ironic the lights come on after brake work.

 

We are in unchartered territory with this one Toto

 

I periodically get those lights randomly. Usually if I shut the car down and restart the lamps go out.

 

The ABD can be switched on with low battery power. There has been a couple of times when my car sits & I start it with a low battery, the lights will be on until, I shut it off & restart. I believe it's the low voltage that sets it off.

If they do not go off, you might be getting a low pressure warning, meaning there might be some air trapped in the lines.

 

maybe air in the brake lines

 

there are also 3 relays on a block under the front boot carpet on the passenger side (at least on my C4) that relate to the ABS system. I found that pulling them and cleaning all the contacts stopped my intermittent dash lights from coming on.

 

a loose wheel, a bad wheel bearing will also generate these lights. Don't ask me how I know this.

 

I didn't get both, but got one with low brake fluid.