[PhasTsupRa]

I have recently found that my ABS system has stoped working. I have my trac removed for a while and everything was fine. I checked for codes and ended up with Code 35 and 36 Failed Right rear and left front Speed sensors and Left rear and right front failed speedsensors. I inspected the sensors and cleaned them. I try to reset the ABS system with no avail , i also reset the ECU. I checked the ECU you for codes and it was clean. I cant get My ABS computer to work again. I cant clear the codes it has either. It only throws codes , doesnt want to go into WSS Special test mode... i just cut the warning lamp so it wouldnt trigger the lamp anymore. I now have no abs. I was wondering if any toyota tech's here could help me reboot this thing and maybe get it working again.

 

[Nick 95 6sp]

not sure about rebooting etc.

But I think some aftermarket swaybars have been reported to break wheel speed sensors. Also, one of my wheel speed sensors was ruined when my rear wheel bearing went bad before I had a chance to replace it but I'm not even 100% sure the wacked bearing caused it, but it was definitely bad and was replaced with the bearing.

 

[Guest]

You know I'm interested as to how hard it was to see the speed sensors? My trac light comes on if I hit a hard bump and my unit becomes non-functional until I restart the car. Was it hard for you to check? (Sorry for not being able to contribute, but I wanted to know)

 

[PhasTsupRa]

Does your trac light come on or both abs and trac? What maybe happening if the sensors are not tightend down is the magnet (sensor) will shift upward on a bump and weaken amplitude and signal frequency their for shutting down the system. Damaged or missing teeth on the sensor ring will show up as flat spots or gaps in the sine wave pattern aswell. A bent axle or hub will produce an undulating pattern that changes as the strength of the sensor signal changes with every revolution. In your cases it indicates a weak signal caused by an excessively wide air gap between the tip of the sensor and its ring, or a build up of metallic debris on the end of the sensor. A weak signal can also be caused by internal resistance in the sensor or its wiring circuit, or loose or corroded wiring connectors. Clean the sesnsors of mettallic debris they are right behind the discs , held down by a single 10mm bolt. Use a deep socket prefrebly. Once you remove it clean the tip , inspect the splines with a flash light , you can add some grease to stop any corrosion or buildup on the tip. After you cleaned and tightened all 4 sensors take a drive , get her on some bumps. If the system fails again Dont restart the car , just leave it running if you can , now get into the diagnostic box , remove the grey short pin and connect trerminals Tc and E1. Look at your ABS lamp and write down the code its throwing. First series of blinks is first digit second series is second digit 2.5 second gap is your second code if their is any , if not it keeps repeation the fist code.

TOYOTA ABS CODES
11 — Open shorted relay circuit. Check modulator wiring harness, solenoid relay, solenoid relay wiring harness and solenoid relay connector.
12 — Short in solenoid relay circuit. Check modulator wiring harness, solenoid relay, solenoid relay wiring harness and solenoid relay connector.
13 — Open pump motor relay circuit. Check modulator wiring harness, pump motor wiring harness, pump motor relay circuit and pump motor connector.
14 — Short in pump motor relay circuit. Check modulator wiring harness, pump motor wiring harness, pump motor relay circuit and pump motor connector.
21 — Open or short in ABS solenoid for right front wheel.
22 — Open or short in ABS solenoid for left front wheel.
23 — Open or short in ABS solenoid for right rear wheel.
24 — Open or short in ABS solenoid for left rear wheel.
31 — Problem in right front wheel speed sensor circuit.
32 — Problem in left front wheel speed sensor circuit.
33 — Problem in right rear wheel speed sensor circuit.
34 — Problem in left rear wheel speed sensor circuit.
35 — Open in left front or right rear wheel speed sensor (WSS) circuit.
36 — Open in right front or left rear WSS circuit.
37 — Faulty rear speed sensor rotor.
41 — Battery voltage too low or high (under 9.5 volts or over 16.2 volts). Check battery and charging system.
51 — Pump motor is locked or pump motor circuit is open. Check pump motor, motor relay, wiring harness and modulator ground connections.
"Always on" (no flash codes, just a steady light) — Malfunction of ABS module

If you get a speed sensor code you need to check that the harnesses are connected properly , the front harnesses are in the engine bay sticking out of the ABS relay , they are grey in color, slide the relay off the bracket and check they are plugged in snug , the rears have the wires coming out under the plastic speaker box behind your rear seat , they them go under the plastic panals and have a harness (grey) right on there , you will see it once you take off the plastic interior panals on both sides. If this still does not solve your problem i can give you s advanced wheel speed sensor check method , and some more ways you can test the entire system along with diagrams. BTW i fixed my ABS system yesterday , turned out to be the harnesses behind the rear interior panals. When i was installing my Speakers and crossovers my Helper mistook it for speaker wire ROTFL :blah: Good luck

 

[Guest]

^^^ Man that is a fantastic write-up. I notice mine seems to be on the left side of the vehicle and when I hit a bump, the TRAC light comes on, followed by the TRAC OFF light a few seconds later. I tried pulling codes after the car was restarted because I thought the ecu stored these, but to no avail. So you say to plug these in while the car's already on, huh? I'll give a look into this, and same with the speed sensors that are sitting behind the discs. I don't get an abs light, though. Only trac.

 

[PhasTsupRa]

Keep in mind the engine ECU computer + ABS computer + Trac Computer all send messages to eachother. Its almost as if they would be one unit. If your trac light is off its highly probable that your abs would reapeat that message , are you sure the lamp itself is ok. The master warning lamp [!] may go off aswell. Does your O/D OFF indicator blink aswell? Did you remove the trac fuse? or do you still make use of your trac system? The O/D light is the ECU talking to you , ABS light is the ABS system and TRAC well its trac.

 

[Guest]

O/D OFF button works, and the light comes on when it's off. So that's fine. TRAC light also works when I lose traction, so that's fine. But like I said, on one of the wheels the traction control is getting a bad signal and then it's causing my traction control unit to turn itself off, basically, until I keep driving the car and turn it off and turn it on somewhere. HOWEVER (and note this), if I were to park the car and turn it off right after hitting the bump to disable my traction control, then turn it back on, the TRACTION CONTROL WOULD STILL BE OFF. So in essence, it'd knock the traction computer off-line, but I'd have to hit something AGAIN to knock it back on-line before I restarted the car, else the traction control would still be faulty.

Also, I make use of my traction control. Every now and then I get the blinking O/D Off light. I am aware that it's a speed sensor code which I tried to fix in the odometer but maybe it's on one of my actual sensors as we are thinking now.

What I will do is when I do my brakes when I go home, I'll find these speed sensors and have a look at them. Not sure what I'll be looking FOR, but I will figure it out. Thanks a TON for your help, and if you have anymore ideas after my further describing the problem, please let me know.

 

[PhasTsupRa]

Check them for magnetic debries , clean and lubricate the tips , corrosion , any splices the wires may have etc.. i bet its the wires if not the speed sensors loose bolts that are causing the problem. A good wheel speed sensor will generally produce an alternating current (AC) voltage reading of 50 to 700 MV when the wheel is spun at a speed of about one revolution per second. So you can check them individually by unplugging the harnesses.If the voltage reading is low or nonexistent, check the sensor’s resistance (with the key off). If the wheel speed sensor doesn’t read between 990 to 1210 ohms, If the sensor has too much internal resistance (opens) or too little resistance (shorts), the sensor is defective and needs to be replaced.Grounds or shorts in the wheel speed sensor cables can be found by checking continuity between the wiring connectors. If a defect is found in the wires that run between the sensor and the chassis, replacing the wires with new ones is a better repair choice than trying to fix or splice them. These wires undergo a great deal of flexing every time the suspension encounters a bump, so new wires will hold up better than ones that have been soldered, spliced or taped. Their is a device that plugs in the Little harness below the steering wheel where a special breakout box can be plugged in to check the systems entire wiring. Its most likely not going to be internal but if you dont find anything wrong with those sensors and chassis wires its worth a shot. Good luck

 

[Guest]

You really know your stuff. I'll be sure to post something up if I find something when I do my brakes in a couple weeks. Thanks again for all your help.

 

[PhasTsupRa]

Man, i spent 3 days drinking caffeine reading about this system and how to diagnose it , entire artical's and schematics. I was determined to get that ABS lamp out. I hate when my supra is blinking codes! I read every post and found that no one had ever actually solved anything and written up a write up. So now im doing my best saving people the headache. You going to HIN event in Boston?

 

[Guest]

Nope, sorry. I will do a write-up if I can find my problem. Thanks again.

 

[supra8388]

Man, i spent 3 days drinking caffeine reading about this system and how to diagnose it , entire artical's and schematics. I was determined to get that ABS lamp out. I hate when my supra is blinking codes! I read every post and found that no one had ever actually solved anything and written up a write up. So now im doing my best saving people the headache. You going to HIN event in Boston?

Great writeup, probably you can help me on this. My O/D is blinking code 89. i have searched everywhere and all i got is people talking about speed seonsor, odo which is not the problem i am very sure caused i have tried those cure it didnt work.

I suspected the TRAC ecu. Do you have any idea? Your input will be much appreciated. Thanks

 

[Guest]

Hey Phast, I finally checked these and I am throwing a 43 on the TRAC light and a 58 on the ABS light, but I don't see those on your list. What are they?

EDIT: Nevermind, looks like I have a bad trac pump or circuit somewhere, and possibly a bad abs ecu or trac ecu.