ABS Code 51 abs not working and intermittent abs light on

Anyone know what to do here? I checked the ground, The main fuse 50 amp is good as well. I unplugged and replugged the ABS wires into the module. I was not sure how to test all the imput wires. But the code says bad ground, or motor jammed. What else can i check. anyway to check the motor to see if it truly is jammed? Any experience with this. Does this cause my braking to me mushier or am i just imagining it being mushy. I can lock up the front wheels when i brake really hard.
Should I open up the abs cpu and try cleaning it?

This all started a few days after i cleaned the engine bay some water prob got near the abs unit.

 

Light is not on at start but lights up after 10 min driving.

 

I did a little leg work for you. You need to check the voltage DROP from where the ground wire(s) from the ABS pump/controller to the actual grounding point. Do this for all grounds that you can see especially the short ground from the battery to the chassis, firewall to the block/head etc.

This article is a VERY good article explaining what is going on, yes it is for the charging system but the principal is the same.


http://www.tomorrowstechnician.com/toyota-charging-system-diagnostics/

 

Thanks for the info I am reading up on it and will check on it tomorrow. Been googling voltage drop it is a new concept to me. What i understand is I want to put the ohm meter on the negative of the battery and the ground near the ABS module and run it to see the drop and hope it is less then 0.2... still reading about this but it is new to me.

 

actually no, you are looking for a DC voltage drop of less that .2 volts. An auto ranging voltmeter like the Fluke shown is the way to go. The various computers in modern cars are very sensitive to bad grounds especially when we are dealing with such low currents.

 

Code has not come on for a few days now. Hopefully it healed.

 

Welp code cam on when driving to a friends but didnt come on when driving back home.. it was a 15 min drive.

 

Update, code went off but then came back intermittently for 2 weeks. was mostly off. Abs was working in the times when light was off and under abs braking cconditions. Came on today and it read 51. Then i checked the battery ground and it was much more corroded than it appeared. I cleaned it and put it back on and the window motors worked much stronger and faster after, indicating a better ground connection. Hoping this was the problem.

 

What kind of scanner do you need to read SRS codes? I have a cheesy generic one (works great for other stuff though) and it's showing no codes, but the light has been on for a long time...

 

i have a 2002 3.4l
You have to use a paperclip and plug it into the wire harness to connect 2 slots. essentially shorting the connection but then you count the flashing light numbers. Connect 13 to 4 with the key just turned on so the radio is on but the engine not on. Then read the number of flashing lights that the ABS does.

Tc (13) and E1/CG (4)

 

I have attached the ABS wiring skematic for a 2003 Tacoma... should be similar if not the same. The Code 51 is telling you either the ABS motor is intermittantly bad or the ground off of the ABS ECU is bad. The skematic shows two large amperage inputs to the ABS ECU a 60 amp and a 30 amp. The grounding point for the ABS ECU is on the right front inner fender with 2 white/black wires. If it was me, I would make an additonal ground wire and attach it to this grounding point and attach the other end directly to the negative post on the battery, secure it and drive it around and try to make the ABS pump work to see if a code is set. If a code is set then the pump motor is suspect.

 

The code has not come on since cleaning up the negative battery terminal. I cleaned off the ground early on and that did not seem to be the problem. I am pretty sure the negative terminal was affecting performance, the window motors would struggle when car was not running but now they run strong.

 

Any updates on this ? Besides the ground is it just the motor that’s shot ?