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Help with ABS disable

MTZ

New Member
Hi all, new here and looking for help. I'm a mechanic, but new to opening ecu's.

I am disabling the ABS system on a racebike, but want to keep the traction control and anti wheelie features and have no ABS light so the diagnostics can still highlight faults. I have the ABS disconnected and plugged up, but want to remove the pump and block to save space.

I would like to know what kind of resistors I should replace the pump motor and solenoids with? The pump windings measure 1.1 ohms, and the solenoids 7.5 ohms.
I'm not sure how to replace the pressure transducer (4 pin)?

Hopefully this is easy. Any help appreciated. Thanks!
 
Last edited:

Diver300

Well-Known Member
Most Helpful Member
You could probably replace the solenoids with resistors around 7.5 Ohms. They will dissipate around 25 W if they operate. That may only be for short periods, so you may get away with smaller resistors but I would suggest wirewound resistors of at least 5 W continuous rating.

The pump will take far less current when running than would be calculated by the supply voltage divided by the resistance, which is around 10 A. It will probably take 2 - 4 A. You could try using the same resistors.

It's difficult to know what would simulate the pressure transducer. The electronics may expect to see a change in reading when the pump runs or the brakes operate. Simulating that could be difficult.

ABS modulators on cars often have quite extensive electronics inside them. Is that the part that you want to keep?
 
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MTZ

New Member
You could probably replace the solenoids with resistors around 7.5 Ohms. They will dissipate around 25 W if they operate. That may only be for short periods, so you may get away with smaller resistors but I would suggest wirewound resistors of at least 5 W continuous rating.

The pump will take far less current when running than would be calculated by the supply voltage divided by the resistance, which is around 10 A. It will probably take 2 - 4 A. You could try using the same resistors.

It's difficult to know what would simulate the pressure transducer. The electronics may expect to see a change in reading when the pump runs or the brakes operate. Simulating that could be difficult.

ABS modulators on cars often have quite extensive electronics inside them. Is that the part that you want to keep?

Thanks for the advice on resistors! I'll give them a try, very helpful.
I had been looking at much larger ones for the pump, because the circuit has a 30 amp fuse, but resistors for that would've been huge.

I would think the pressure transducer will be used by the computer for diagnostics, but I'm not sure. It will be an experiment replacing this. I was hoping to try taking a fixed atmospheric reading from the sensor to use. But, I'm not sure how to test this for a suitable replacement, there are 4 terminals but no indication of what each is? Although, there is a split between the top and bottom terminals in the picture below.
Screenshot_20221008_165555_edit_804100158725215.jpg

I would probably keep the transducer, but I don't think I can remove it from the block without destroying it.

Yes, I want to keep the electronics as they share wheel speed etc. with the engine control unit. There are commercially available ABS delete plugs to replace the whole ABS unit, I'm not sure how they simulate the pressure, or if they do, but they seem to work without creating fault codes. None in stock at the moment, and pretty expensive.
 

MTZ

New Member
I've had difficulty finding info on testing the pressure sensor, but it seems it probably has a 5v feed, an earth, a signal live, and a signal earth.
If I wanted a fixed value to bypass the sensor, can this be done with a voltage regulator or is there a better way? Thanks

This type sensor seems to have been a common fault in cars, and the company in the link below claims to bypass the sensor without creating fault codes.
 

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