Here is what is have on it...

Have tried resetting the PCM yet?


ABS Light Reset


I finished a complete brake job on my 2001 Ram 1500 this weekend and couldn't get the ABS and brake light on the dash off no matter what I tried. The only thing that worked was to put a jumper in the OBD/DTC connector under the dash (where you plug in the data scanner). Confirm that you have a 16 pin connector and open up a small paper clip to make a jumper. Insert that into pin 4 (4th from the left on top) and pin 13 (4th from the right on the bottom) Turn the key on and pump the brakes rapidly 8-10 times. Turn off the key. The lights will be off. This only resets the lights so, if you have not corrected the underlying problem, the lights will come on again.



On the RWAL (Rear Wheel Anti Lock) module which sits 3" closer to the firewall than the proportioning valve, there is a rubber cap pointed horizontally right towards the master cylinder. Poke a paperclip thru the rubber cap about 1-1/2" until it touches the back of the RWAL accumulator piston. With key off, have a friend press and hold pressure on the brake pedal. If the piston moves, the service manual says to replace the RWAL. Mine moved, so the RWAL is supposedly bad. The only way for brake fluid to move the piston in the accumulator is for the anti-lock solenoid to be energized with battery voltage via the green wire on the "A" terminal of the connector... (OR if the solenoid valve is blocked open??, I thought.)

The leaking valve seat let fluid pass into the accumulator. The accumulator is spring loaded, so the "leak" doesn't go on the ground, rather it's collected in a spring loaded piston chamber and when you let off the brake pedal, the spring pushes the fluid back into the rear brake hydraulic lines & back into the master cylinder. Viola! Mushy pedal in spite of the following; brand new master cylinder, no air in system, fully bled system, NO visible fluid leaking under the truck.

My solution: My master cylinder reservoir was filthy with little black hunks of ??? in it. I suspected a chunk got caught under the solenoid valve seat during a hard stop yesterday, so with the key off/engine off I put 12volts to the green wire to energize the accumulator solenoid and repeatedly pressed the pedal to the floor and let it rest 10 seconds for a couple minutes. My theory was I could repeatedly fill and empty the spring loaded piston chamber of the accumulator and dislodge whatever might be blocking open the solenoid valve seat. SHAZAM! It worked...

If this problem comes back, I will do one of the following: Install a used RWAL module (new is big buck$) and powerflush all four corners again, or I will disconnect the rear brake lines from the RWAL module, connect them directly to one another, flush/bleed the system and effectively bypass the dang RWAL system.


If you end up with the proportioning valve shutting off the circuit you are working on, close all bleeders on that circuit, go to the OTHER end of the truck, have helper pump up the brakes, and HOLD it, then release one of the bleeders. This will get the p-valve to release again. Go back to what you were doing previously.



I checked all the soft lines and didn't find any leaks or kinks. However, I did have a new development today. Took the truck for a drive around the neighborhood and the brake pedal was behaving as normal. Then, suddenly, the pedal became mushy and went down to the floor while still stopping the truck. I messed with it some more and found that when I step on it hard, it has some resistance, but when I ease into it, it just sinks down. I did a little bit of research and read that this can be cause by a bad master cylinder seal. Then I read that the seals can fail if the brake fluid hasn't been changed in a while and then you attempt to bleed the brakes. Something having to do with buildup at the end of the cylinder that doesn't get used under normal circumstances, but can cause damage when the pedal is dropped to the floor during bleeding, which would make sense since I don't know when was the last time that the system was drained before I had it done a couple of days ago. This is all fine and good, but could this also be the cause of the lack of rear brakes? I'm thinking no since the the rear brakes seem to have failed BEFORE the fluid drain, but input is greatly appreciated.

 

with scantool i have only this error:
P0051
P0053
P0071
P0073

 

I think the first two are for your O2 sensor (replace it), and you intake sir temp sensor seems bad too.

Have you disconnected the battery for 15 minutes to reset the PCM yet?

 

Have you disconnected the battery for 15 minutes to reset the PCM yet?
---Yes

 

You are getting codes for both O2 sensors.... How old are they?

Intake air temp sensor is probably toast, as dbbd1 says.

Those are powertrain codes, the typical handheld scanner the parts stores have, won't read abs codes. Which is what you need.

 

Guys today I took the continuity test of the abs pump connector (2 ways, red and black) and there is continuity between red and black..the pump is dead?

 

Certain codes will disable the ABS system. You really need to get your codes read, and see what the system is whining about.

 

Are both lights on? Try pulling the ABS codes by grounding pin 13

 

How exactly do you ground pin 13?

 

Straighten out a paper clip and short pins 4 and 13 together.