ABS DTC code 51 (2 Viewers)
- Thread starter lt403
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Closing out this thread for myself and any future searchers.
Shout out to @slow95z. He got me the used ABS controller quickly and as advertised for a good price.
Installation was pretty simple. There are always the corrosive concerns whenever working with DOT3 fluid. Bleeding was more of a challenge as no fluid was moving initially. I correctly figured I needed to activate the ABS controller to start the fluid flow. I used the jack stand method in this old thread Is there a way to trigger ABS actuator to combat spongy breakes?. From there, bleeding was straight forward.
That same thread gives you the wiring diagram to manually activate the ABS controller using jumper wires. I was asking about that capability earlier in this thread, so I thought I'd give it a go on my old ABS controller and see if that got it working. Nope. Dead as a doornail. So the ABS code 51 seems to be a legitimate indication the ABS controller is dead.
ABS is back functioning properly with no more codes. Thanks for the help everyone.
Shout out to @slow95z. He got me the used ABS controller quickly and as advertised for a good price.
Installation was pretty simple. There are always the corrosive concerns whenever working with DOT3 fluid. Bleeding was more of a challenge as no fluid was moving initially. I correctly figured I needed to activate the ABS controller to start the fluid flow. I used the jack stand method in this old thread Is there a way to trigger ABS actuator to combat spongy breakes?. From there, bleeding was straight forward.
That same thread gives you the wiring diagram to manually activate the ABS controller using jumper wires. I was asking about that capability earlier in this thread, so I thought I'd give it a go on my old ABS controller and see if that got it working. Nope. Dead as a doornail. So the ABS code 51 seems to be a legitimate indication the ABS controller is dead.
ABS is back functioning properly with no more codes. Thanks for the help everyone.
I am also getting a code 51 and have been cleaning ground connections throughout. I also upgraded the grounds from the battery with no luck. I'll be (hopefully) getting an ABS motor and will let you know what the results are.
You could try hot wiring it, like the link in post 23 describes. That creates new grounds. In my case, I just got a big spark jump with the connectIon to the battery. No solenoid engagement. However, no one on this thread seems to have solved the code 51 without replacing the controller.
Good luck.
Good luck.
My personal opinion is because the brushes like on every electric motor eventually wear out. The code indicates a stuck pump motor. If the motor shaft isn't spinning it's either jammed, or there's no field pushing through the armature. As I said in a previous commitment I thought there was someone rebuilding the motors. Seems like a good niche to get into. Especially with the age of some of these vehicles out there. It's only a matter of time before everyone will need it done.
What's odd is in the diagnostic manual I came across online, Code 51 had two parts to it. If the buzzer was on and the light was on then the pump motor was locked. However, if only the light was on, according to the manual, the problem lay in the MT+ or MT- harness. (Not sure what MT refers to but assume it's referring to pos and neg wires in ABS system)
@hobbes Was your buzzer on when you had the code?
@hobbes Was your buzzer on when you had the code?
I'm also unsure of which buzzer it's referring to. The link I had is now dead, or else I would post it up. Let me see if I can find it...
I think I could hear a slight humming on mine when I jumped it. Motor was probably locked. I've got my old one sitting in a box. Not sure if I want to toss it or not.
I've been unable to find that diagnostic sheet I was looking at, but here's another thing to consider.
The PO installed a new booster and master cylinder a month before I purchased the vehicle (everything has been performed by the dealer for the past 25 years). He said the ABS line came on right after he had those replaced. So, I'm wondering if when the car was bled it dislodged some gunk in the lines causing the ABS pump to lock. I have a used one on the way, but am thinking a purge from the link you provided may help.
Thoughts on the connection between a new master cylinder and a Code 51 coming on right after it's replaced?
The PO installed a new booster and master cylinder a month before I purchased the vehicle (everything has been performed by the dealer for the past 25 years). He said the ABS line came on right after he had those replaced. So, I'm wondering if when the car was bled it dislodged some gunk in the lines causing the ABS pump to lock. I have a used one on the way, but am thinking a purge from the link you provided may help.
Thoughts on the connection between a new master cylinder and a Code 51 coming on right after it's replaced?
Mine occurred right after I did some front axle work. I was convinced when the light came on it was due to that. Turns out that was an incorrect assumption in my case. I don’t know why changing a master/booster would cause a 51 code. Perhaps if they actuated it to bleed the brakes that was coincidentally it’s last gasp?
Just want to confirm that replacing the ABS pump with a used pump SOLVED the ABS Code 51 for me. Was pretty easy to bleed and besides one of the ABS lines needing to be torched to loosen up, went smoothly.
