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· 1st RFM/FFR Legacy Winner
29,388 Posts
Discussion Starter · #1 · (Edited)
I summarized 5 months worth of research, design, and testing here, hopefully making it easier for anyone so inclined to add ABS to their car. Much of the information, execusion, and data presented is my own. I strived for complete accuracy but use this information at your own risk. - Greg

NOTE: 6/29/14 - All the linked photos from "worldisround.com" are lost due to website crashed.
EDIT: 1/21 - I added a link that works to most of the recovered photos. Greg_M Cobra

Installing the Bosch 2U 3-channel ABS controller, tone rings, and sensors from the 1994/1995 Mustang on an FFR

Ford Parts list:

1994/1995 ABS controller with mounting bracket, number stamped into ABS module, 265 207 000, and 091 463 20810 9 electronics control module attached.

F72C-2C205AA - Left Front wheel sensor with mounting bolt
F72C-2C204AA - Right Front wheel sensor with mounting bolt
F72C-2C216AB - Left Rear wheel sensor with mounting bolt
F72C-2C190AB - Right Rear wheel sensor with mounting bolt
F4ZZ-2C189-A – 50 tooth tone ring for each rear pre-94 axle (or 94+ axle with tone ring attached)
7L8Z-2C182-B – 50 tooth tone ring for SN95 front spindle (SN 95's should have them installed)

Other Parts:
35' of 18ga twisted pair wire to connect wheel sensors to ABS module. If twisted pair is not available, use 70' (two 35' lengths) of 18ga stranded wire, single color is fine, and twist the single wires into a twisted pair with a drill motor.

8' each of 18ga multicolor stranded wire to connect control signals to the ABS controller

35' of 1/4” wire loom to cover sensor and control wires.

4' of 3/4” wire loom (or taping is optional) to cover main harness from ABS controller to car

One 60A fuse and holder to fuse the ABS controller main power feed.

10 feet of #10 wire to feed ABS main power and pump motor ground.

A means to connect the short OEM harness from controller to car (12-pin terminal strip or Molex plugs)

A means to connect large OEM power and ground wires from controller to car (60A 3-pin terminal strip or connector)

Dash mounted 12V lamp or LED to indicate ABS system status and error codes

A means to place ABS in diagnostic mode (either a single pole switch or a 2-pin Molex plug/receptacle)

A single pole switch to disable ABS (optional)

Brake lines (length is installation dependent) with flare adapters or the old OEM bubble flare fittings that came with the used ABS module

Wire ties and cable clamps to secure sensor and control wiring.

Procuring the ABS parts:
The ABS controller, sensors and tone rings are frequently available on eBay. Controllers with mounting bracket and short wiring pigtails go for between $10 and $100, a set of rear tone rings for $25 - $75, front or rear sensors for $35 - $75 a pair.

Cleaning the ABS parts:
Clean dirt from the ports with a dry swab being careful not to force any dirt into the holes. Block ports with a piece of rag and clean exterior of controller by hand with lacquer thinner on a rag. Follow that with 409 type cleaner with a rag. DO NOT SPRAY WITH WATER. Clean the sensors the same way. They are sealed so water will not hurt them.

Testing the sensors:
Test the sensors with an Ohm meter. Each of the ones I specified will read 1,650 Ohms. Unless you have, and plan to use the matching plug from the Mustang wiring harness, you can cut off the sensor's plug and strip the wires back 1.5”.

Bench testing the ABS controller:
I highly advise that you check the functionality of the controller prior to installation. Use the following wiring diagram to connect it on the bench: http://www.worldisround.com/hosted/30/203/34_o.jpg Here's a photo of it wired on the bench: http://www.worldisround.com/hosted/30/217/210_o.jpg
Be sure to connect the large ground wire on the motor as well. Substitute a resistor of any value between 1,000 – 10,000 Ohms in place of each wheel sensor. You could instead, wire the wheel sensors to the controller, whichever is most convenient. The controller does not care about sensor polarity so it does no matter which sensor wire goes to the + and – on the controller's sensor inputs.

On power up, the controller runs a self test which should light the ABS lamp, click 2 relays, and then extinguish the ABS lamp. This all occurs within 2 seconds. The self test checks the following: continuity on each wheel sensor, continuity of the three solenoid valve coils, continuity of the ABS pump motor. It does so by passing a very small (0.2V) supervisory voltage through these components and monitoring for a 0.1 mA current draw. The supervisory voltage is always present whenever the controller is on so anytime a monitored component fails, the ABS lamp will illuminate, disable ABS function and store an error code. Battery voltage is also monitored and will produce an error if it drops below 10V.

If the ABS lamp stays on, the self test failed and codes will be available to diagnose the fault. To read the codes (up to 3 are stored in memory), ground the orange/white wire and power up the controller. The ABS lamp will light and one relay will click. The ABS lamp will then blink a series codes. For example, 3 flashes followed by 2 flashes (code 32) means right rear ABS sensor continuity fault The next codes will display if present and then the lamp will turn on solid. Use these codes to remedy the fault(s).

12 - system OK
19 - anti-lock control module
22 - right front valve
24 - left front valve
26 - rear valve
31 - right front ABS sensor continuity fault
32 - right rear ABS sensor continuity fault
33 - left front ABS sensor continuity fault
34 - left rear ABS sensor continuity fault
41 - right front ABS sensor
42 - right rear ABS sensor
43 - left front ABS sensor
44 - left rear ABS sensor
61 - pump motor/pump motor relay fault
63 - voltage supply interruption
69 - vehicle battery voltage less than 10VDC
78 - ABS sensor frequency fault

If the controller passed the self test, test the real-time fault monitoring next. With the controller power on, disconnect one wheel sensor or its substituted resistor. Within 2 seconds, the ABS lamp should turn on indicating a system fault is present. Reconnect the sensor or resistor and power cycle the controller. The self test should now pass.

The next test is for the operation of the hydraulic solenoid valves. Remove the plastic cover on the electronics module by removing the single Torx screw. The cover lifts off with a little pressure. Remove the plug to the solenoid valve coils from the main circuit board. This plug has 6 black, yellow and green wires. Carefully and momentarily connect 12V between the Black-Green wires on the plug (not the circuit board). You should hear a distinct click from the solenoid valve. If you see a spark when disconnecting but no click, the valve is stuck. Repeat this test for each of the Black-Yellow wire combinations and note the click. They should click as well. If you get no spark, test the continuity for a reading of 1.5 Ohms for each valve coil. See the pin-out and plug here: http://www.worldisround.com/hosted/30/217/202_o.jpg http://www.worldisround.com/hosted/30/217/199_o.jpg

If the solenoid tests fails, you have a couple of options. 1. Get you money back and buy another controller. 2. Try heating, tapping, and electrifying the stuck valve and hope it unsticks. I would not recommend taking it apart unless you are desperate. If the solenoid coil is electrically open, you will have to get another controller.

The final test is to see if the pump motor will actually run. Disconnect all power and ground wires to the controller that were used for the self test. You can simply pull the large and the small square connector from the electronic module. Connect a 12V battery ground to the pump motor ground stud (this is an isolated ground from the rest of the controller). Momentarily connect the battery positive to the top of the Torx screw located directly beneath the relay nearest the edge of the circuit board. See “pump motor drive caption” in this photo but note Torx screw is removed. Leave screw in for this test http://www.worldisround.com/hosted/30/217/202_o.jpg http://www.worldisround.com/hosted/30/217/200_o.jpg
The motor should spin up. Hold on to the controller because the motor is quite strong and will try to flip the controller over! If the motor spins fast, you are done.

This concludes the bench testing procedure.

Installing the system:
Mount the ABS controller in a convenient location. Closer to the master cylinder will allow for the shortest brake lines. Here are a few choices for mounting location:

You must decide how to connect the controller's wiring to the car. I used a 12-pin terminal strip for the low current connections but another choice is Molex connectors. The 60A main power feed and the two ground connections require a robust method of connection. I used a terminal strip for these as well. Here's my mount and how I interfaced the wiring connections: http://www.worldisround.com/hosted/30/203/255_o.jpg

The wiring diagram is fairly self explanatory. Note the wire color changes made for the Left-front and Left-rear sensor (-) connections. http://www.worldisround.com/hosted/30/203/34_o.jpg When wiring the sensors, be sure to use twisted pair wire or use a drill motor to twist two single 18ga wires into a pair before placing them in the protective sleeve. The sensor connections to the controller are designated positive/negative but the controller is not phase or polarity sensitive so there is no need to follow the polarity convention.

For ease of plumbing you can even swap the Left-front and Right-front brake line outputs to the controller if you also swap the Left-front and Right-front sensor wiring inputs to the controller.

The front wheel sensors are very easy to install assuming you have SN95 front spindles. The sensors will fit the existing mounting holes and the harness is the correct length to fit in the wheel wells. Of course you will have to extended the harness with additional twisted pair back to the controller. For information on front wheel sensor mounting go here: http://www.worldisround.com/articles/123897/photo543.html and

If your FFR uses an SN95 based rear end and front spindles refer to this document to guide you through the installation: http://www.corral.net/tech/handling/abs.html

If your FFR use a pre-ABS (1987-1993) rear end with disc brake conversion, start here to see the modifications required to adapt tone rings to the rear axles:

Testing the system and first drive
After filling and bleeding the brakes as you would any conventional braking system you are ready to go for a test drive. Start the car and verify the ABS lamp turns on/off within 2 seconds. If not, the self test has failed and you must read the error codes and remedy the failure before ABS will function. If all is well, drive at varying speeds and make moderate stops all the time checking the ABS lamp for illumination. If it stays off, the ABS is operating. Make a few panic stops and note how the pedal feels. You should feel no hint of ABS in the pedal as long as the car is not inclined to skid. Now purposely induce a skid and note when any tire has the first hint of locking, the brake pedal pressure will increase. You will feel little or no pulsing, just a steady pressure until the car comes to a complete stop. During the last 10 feet, the pedal may pulse very slightly and a “chuffing” sound is audible from the tires. The ABS pump motor may continue to run for a second after the car completely stops.

Additional data and links of interest
The ABS controller input current with no faults and ABS lamp off is 360mA

The ABS module will pass the self test with any wheel sensor substitute resistance between 0 – 20,000 Ohms. The module does not check for wheel sensor shorts only wheel sensor open faults. However, if a sensor were to short it would not produce a waveform when the car moves so the ABS would identify that as sensor frequency fault and produce a 41-44 error code.

If you want to check the ABS module's ability to identify a sensor frequency fault, disconnect one wheel sensor and substitute a resistor between 1000 and 10,000 ohms. Drive the car a few feet. The ABS lamp should light and the resultant error code will be a 41-44 code.

If you want to simulate full ABS operation on the bench, set the controller up as described in the “bench test” procedure. Configure two signal generators for 300 Hz, sine wave, 1V p-p output. Couple the output of generator-1 using 10 uF caps to the Front-left and Front-right sensor inputs. Couple the output of generator-2 in the same fashion to the Rear-left and Rear-right sensor inputs. Apply 12V to the BOO (brake on/off) wire and rapidly reduce the frequency of one of the signal generators. This will simulate a skid. The valves will pulse rapidly and the pump motor will run.

Three ABS faults are stored in memory for many on/off cycles unless the car is driven for a few minutes above 30 mph. Driving the car over 30 seems to erase the codes quickly.

The ABS will “kick in” as slow as 5 mph.

A wheel sensor voltage waveform: http://www.worldisround.com/hosted/30/198/515.jpg

The gap between the tone ring teeth and the sensor magnet is 0.027” – 0.030”.

New EOM rear axle tone ring source ($30): http://www.mustangmagicparts.com/motorcraft-f4zz2c189a-abs-p42189.html

A good website for troubleshooting: http://www.veryuseful.com/mustang/tech/brakes/absDiagInfo.html

A good website for installing ABS on an SN95 vehicle: http://www.corral.net/tech/handling/abs.html

Adding ABS to a pre-ABS FFR : http://www.ffcars.com/forums/showthread.php?t=260335

A great explanation on pages 116 – 117 on how the ABS module works: http://books.google.com/books?id=sj...=11&sqi=2&ved=0CHkQ6AEwCg#v=onepage&q&f=false

Three good videos made by a FFR member demonstrating the module bench test procedures:

A look inside the ABS hydraulic module: http://www.worldisround.com/hosted/30/227/224_o.jpg

The four major pro's of having ABS:
1. Not flatspotting tires in an emergency stop.
2. Shorter braking distance on surfaces that are wet, rough, or suboptimal in any way.
3. Being able to apply more brake to the more heavily loaded outside tire in a turn, which increases the overall braking ability in a turn. In this case, ABS is a dynamic side-to-side proportioning system which you can't achieve with a front/rear proportioning valve or balance bar.
4. Steering ability is maintained in a turn during emergency braking with no fear of the front wheels locking.

Have fun with this,

· Premium Member
883 Posts
Greg, thanks for a great write up. i have beenm following this ABS on the forum and have collected all the parts for my install. This write up puts the icing on the cake.
Thank You again.

· Registered
1,169 Posts

Outstanding post. thanks for saving me a ton of time searching info.

Will be saving off here in a moment or two to my FFR "Things to know" folder.

· Senior Charter Member
382 Posts


Had my ABS parts in a box for two years. Did some initial research and found some instructions here and there but the decides to drive the car and fit the parts in winter.
Never happened.

Now I found it was time and have three free days to finish my project. Your instruction (I never realized they were FRESHLY published) will help a lot.

Thanks a lot.


· 1st RFM/FFR Legacy Winner
29,388 Posts
Discussion Starter · #8 ·
You are welcome. That goes for everyone who responded.

Good luck and enjoy the benefits of ABS,

· Registered
7,966 Posts
Greg, just wanted to say thanks again for the testing procedure on the ABS system. Just finished wiring and testing mine, it passed every test just fine. Guess I was lucky, as it sat for over a year before I got to this point. I owe you a cold one.

· 1st RFM/FFR Legacy Winner
29,388 Posts
Discussion Starter · #11 ·
That's great news. You got lucky.


· Premium Member
9,683 Posts
Has anyone adapted ABS to a 9" rearend?

· Registered
3,245 Posts
As you know, your car was an inspiration while I was building mine. While I don't plan to follow you down the ABS path, you continue to be a source of information and inspiration,

· Registered
368 Posts
Aww, I really, really wanted to go the ABS route, but adapting it to my 55" fox axle looks beyond my skill. If anyone does machine the ring plate I'd buy a pair...

· Registered
1,560 Posts
Awesome Job Greg

I will be sure to test mine before the body goes on. Please describe the difference in your brakes. I am sure you put it through the paces by now. I didn't notice if you had Power Brakes or not prior.. Are you glad you did it? Just curious of your impressions.. Thanks again for doing the hard work and documenting it... JJ

· 1st RFM/FFR Legacy Winner
29,388 Posts
Discussion Starter · #19 ·
Yes I had/have hydroboost brakes. Two words best describe the brakes; safe and predicable. I never worry about sliding the front tires and with the computer controlled variable F/R proportioning, the rears work harder than they did before ABS. I can apply more brake to the more heavily loaded outside tire in a turn, which increases the overall braking ability in a turn. In this case, ABS is a dynamic side-to-side proportioning system which you can't achieve with a front/rear proportioning valve or balance bar.

It's the best mod I have done.

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