01 Dodge Ram 1500 ST 5.2 Magnum....Has anyone had an issue with the ABS/Brake light coming on and getting a spongey pedal? Had this happen last year when it got hot " Texas " then it kinda fixed itself...OBD2 says ABS is fine. I have changed the rotors/drums pads and shoes, bled system a few times. Replaced that sensor on top of the pumpkin, replaced the one in the transmission, etc to no avail. Any ideas would be greatly appreciated. The only thing I can think of is maybe I ran one of the exhaust pipes too close to a brake line causing the fluid to get too hot, kinda like back in the day getting vapor lock from the gas line due to exhaust pipes. I dont know but it getting very frustrating.

 

Might be a rusted brake line...... the line running to the rear is notorious for that.

 

Spongy pedal would indicate a hydraulic issue and there is a switch in the combination valve that get closed if the pressure differential between front and rear gets too large. See if the error indication goes away when you disconnect the switch. If so it's definitely something with brakes lines/hoses or maybe wheel cylinder.
What tool are you using the read the ABS module ? Unless it's something that can talk on the CCD bus you might be getting a false reading.

 

I'm having a similar issue and I plan to replace my master cylinder. It's very old and periodically, my brake light comes on and I can feel the pedal become somewhat spongy at times on long trips, but the truck still stops fine and the master cylinder is full of fluid. All of my brake lines (hard lines with stainless and rubber lines with braided flex lines) have been replaced. I drive another older car and solved this type of issue by replacing its master cylinder.

 

I just used that free junk from Autozone which more than likely gave a false reading, because the ABS system is not working properly.

 

Go find some gravel or mud and lock up the brakes so the ABS activates. Then bleed your brakes. Air may be trapped in the ABS valve.

 

When both lights come on it means there is a fault in the ABS system. As mentioned did you look for leaks anywhere? Did your fluid level drop? Depending on your scanner it may not show ABS faults.