cant pull abs codes

um i tried like ten times to pull the abs codes and i did research this. b/c i found that there are special rotors? i have an 88 TC. i just ordered a new rotor from napa for the left rear and the right rear was fairly new. could this cause the abs light to stay on? the rotor cost 30 bucks. the light was on before i changed the rotor. i had to change it bc it was all tore up like a cheese grater. so i guess im stuck with the light is the way it seems. will i at least have front abs breaks? thanks

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1966 mustang
1988 tbird

Only the FRONT rotors have the ABS exciter rings intergal with the rotors. Rear rotors dont.... ABS exciter ring is the thing on the axle in back of the rotor that looks like a big gear.

If the yellow ABS light is on, the entire ABS system is disabled.

If the ABS light is on, but you cant get codes, check the ABS power relay to be sure it is powering up the ABS computer. If the relay fails to energize because it is bad or isnt getting power to energize it with the key in RUN, the ABS light will come on via the normally closed contacts in the relay.

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Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 21 psi, forced air intercooler, water injection, bypass valve, Ranger roller cam, subframes, etc., etc.. // 86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP nitrous, ignition, gears, suspension, etc., etc.... // 91 Escort: Bone stock winter car // 04 Taurus Duratec (wifes car)

ok Jeff, so check power to the abs pc in the trunk. My light is yellow that is on too. so it is disabled. and im guessing still checking for power to the pc is the first step.

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1966 mustang
1988 tbird

That is a good place to start since it wont output codes. Troubleshooting the ABS system can be a long painful process.... the Ford shop manual has about 50 pages of flowcharts for the ABS system.

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Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 21 psi, forced air intercooler, water injection, bypass valve, Ranger roller cam, subframes, etc., etc.. // 86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP nitrous, ignition, gears, suspension, etc., etc.... // 91 Escort: Bone stock winter car // 04 Taurus Duratec (wifes car)

WOOOHOOO Im excited now. damn this is gonna suck lol.

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1966 mustang
1988 tbird

Another thing that will cause the ABS light to be on all the time is if continuity is lost between the ABS computer and one or more of the ABS sensors. On our 18 year old cars, it's not uncommon to find the shielded cable frayed and broken; I just repaired my front two sensor cables and ABS is now operational again, so check the cables, too.

HTH

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Joe F.

JR's Place - My 87 TC

[This message has been edited by JoeCool (edited 05-17-2005).]

Originally posted by JoeCool:
Another thing that will cause the ABS light to be on all the time is if continuity is lost between the ABS computer and one or more of the ABS sensors.

True, a bad sensor cable will make the ABS light come on. However only after moving. With a bad sensor cable, if the engine is started and the car is at a standstill, the ABS will go through its checks and the light should go off (if no other faults are present). Once moving, the light will then come on.

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88 Silver T/C, original owner, 260,000 miles.
Loaded with everything except leather & auto trans.
K&N, Gillis(18 psi), SVO roller #1, big SS valves, ported intake, head, & exhaust.
Short block & turbo original/untouched.
Spec-II/III combo clutch assembly ordered.
Polyurethane bushings throughout, Goodyear GT-HR 235/55R16's.

Originally posted by PetzJC:
True, a bad sensor cable will make the ABS light come on. However only after moving. With a bad sensor cable, if the engine is started and the car is at a standstill, the ABS will go through its checks and the light should go off (if no other faults are present). Once moving, the light will then come on.

Incorrect.... if the ABS computer senses an open or short in one of the wheel sensors, the ABS light will be on all the time, even if the car is standing still. I know for a fact this is true after the furry creatures of the forest chewed thru my cables TWICE this past winter.

If the ABS computer believes the sensor is in the correct resistance range (i.e., not open or shorted) but the ABS comp doesnt get a correct signal from one (or more) sensor(s) due to the sensor being demagnetized, incorrect sensor-exciter ring gap, damaged exciter ring, etc, then the light will only come on when the car is moving.



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Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 21 psi, forced air intercooler, water injection, bypass valve, Ranger roller cam, subframes, etc., etc.. // 86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP nitrous, ignition, gears, suspension, etc., etc.... // 91 Escort: Bone stock winter car // 04 Taurus Duratec (wifes car)

If the ABS light is always on once the key it turned to On, i'd check voltage to the ABS module as Jeff stated. It is the first check.

i have much of the ABS info on my website. Here's step 1 if you have the ABS light On all of the time the ignition key is On:
http://www.tbirdheritage.com/turbocoupewebsite/abspinpointtestsx2.php?s=&actionstepid= A1

By the way, you don't really need a breakout box, it just helps. If you need the wire colors, let us know. i don't have that info right now, but can check later, if someone else doesn't reply with that info.

It is possible to have a wheel sensor cause the lamp to turn on immediately, prior to motion.

[This message has been edited by JT (edited 05-17-2005).]

Originally posted by Jeff K:
If the ABS computer senses an open or short in one of the wheel sensors, the ABS light will be on all the time, even if the car is standing still.

That is interesting because I just spliced in a new length of cable on my right rear sensor. It was broke (open) when conducting the resistance check, and the ABS light only came on once moving....damn electrons have a mind of their own sometimes....

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88 Silver T/C, original owner, 260,000 miles.
Loaded with everything except leather & auto trans.
K&N, Gillis(18 psi), SVO roller #1, big SS valves, ported intake, head, & exhaust.
Short block & turbo original/untouched.
Spec-II/III combo clutch assembly ordered.
Polyurethane bushings throughout, Goodyear GT-HR 235/55R16's.