Here's the drill on checking & clearing ABS codes with nothing more than a wire jump link. Note that this is for the 99 model specifically. Later models have a different procedure. The entire thread has helpful pics too >
forum.ih8mud.com/100-series-cruisers/491914-abs-engaging-99-lc.html#post6706776
Note - an obd scanner will not show you the ABS DTCs - you either need Techstream, a handheld tester, or
you can use the steps in the FSM under "In case of not using TOYOTA hand−held tester".
Here's how to get the DTCs (out of the '99 FSM):
PRE−CHECK
1. DIAGNOSIS SYSTEM
(a) Check the warning lights and buzzer.
(1) Release parking brake lever.
(2) When the ignition switch is turned ON, check that
the ABS warning lights go on for 3 seconds.
(3) Check the BRAKE warning light lights up when the
ignition switch is turned ON and the light goes off
when the engine starts.
(4) When 120 seconds have elapsed after the ignition
switch was turned ON, depressing and releasing
the brake pedal continuously with full stroke 15 − 20
times within 10 sec. Warning light lights up and
buzzer sounds.
HINT:
If the indicator check result is not normal, proceed to troubleshooting
for the ABS warning light circuit (See page DI−294).
(b) In case of not using TOYOTA hand−held tester:
Check the DTC.
(1) Disconnect the short pin from DLC1.
(2) Using SST, connect terminals Tc and E1 of DLC1.
SST 09843−18020
(3) Turn the ignition switch ON.
(4) Read the DTC from the ABS warning light on the
combination meter.
HINT:
If no code appears, inspect the diagnostic circuit or ABS
warning light circuit (See page DI−294 or DI−303).
As an example, the blinking patterns for normal code and
codes 11 and 21 are shown on the left.
(5) Codes are explained in the code table on page
DI−225.
(6) After completing the check, disconnect terminals Tc
and E1, and turn off the display.
If 2 or more malfunctions are indicated at the same time the lowest
numbered DTC will be displayed 1st.
(c) In case of using TOYOTA hand−held tester:
Check the DTC.
(1) Hook up the TOYOTA hand−held tester to the
DLC3.
(2) Read the DTC by following the prompts on the tester
screen.
HINT:
Please refer to the TOYOTA hand−held tester operator’s manual
for further details.
(d) In case of not using TOYOTA hand−held tester:
Clear the DTC.
(1) Using SST, connect terminals Tc and E1 of DLC1
and remove the short pin from DLC1.
SST 09843−18020
(2) Turn the ignition switch ON.
(3) Clear the DTC stored in ECU by depressing the
brake pedal 8 or more times within 5 seconds.
(4) Check that the warning light shows the normal
code.
(5) Remove the SST from the terminals of DLC1.
SST 09843−18020
(6) Connect the short pin to DLC1.
HINT:
Disconnecting the battery cable during repairs will not erase the
DTC in the ECU.
(e) In case of using TOYOTA hand−held tester:
Clear the DTC.
(1) Hook up the TOYOTA hand−held tester to the
DLC3.
(2) Turn the ignition switch ON.
(3) Operate the TOYOTA hand−held tester to erase the
codes.
(See TOYOTA hand−held tester operator’s manual.)
(f) (Reference):
Using TOYOTA break−out−box and TOYOTA hand−held
tester, measure the ECU terminal values.
(1) Turn the ignition switch OFF.
(2) Hook up the TOYOTA break−out−box and TOYOTA
hand−held tester to the vehicle.
(3) Turn the ignition switch ON.
(4) Read the ECU input/output values by following the
prompts on the tester screen.
HINT:
TOYOTA hand−held tester has a ”Snapshot” function.
This records the measured values and is effective in the
diagnosis of intermittent problems.
Please refer to the TOYOTA hand−held tester/TOYOTA
break−out−box operator’s manual for further details.
I'll bet you a beer that its a failed wheel speed sensor - $170 fixes that if so.