5A–34
BRAKE CONTROL SYSTEM
Part Location (RHD model)
D08RW623
Legend
(1) F–2
(2) F–3
(3) H–33
(4) H–7
(5) H–46
(6) C–16
(7) E–42, E–43, M–8
(8) E–47, E–48, M–1
(9) B–13 or B–14
(10) C–13
(11) H–4, H–5, H–6
(12) H–10, H–11
(13) E–4 (4JX1)(14) E–30 (4GJ2, 6VD1/6VE1)
(15) Fuse Box
(16) H–42
(17) C–41
(18) C–85
(19) C–4 (EHCU)
(20) Relay & Fuse Box
(21) C–39
(22) H–13, H–15, H–16, H–26, H–27
(23) I–10
(24) I–9
(25) H–12
(26) C–63
(27) B–25
5A–35 BRAKE CONTROL SYSTEM
Symptom Diagnosis
The symptoms that cannot be indicated by the warning
light can be divided in the following five categories:
1. ABS works frequently but vehicle does not
decelerate.
2. Uneven braking occurs while ABS works.
3. The wheels lock during braking.4. Brake pedal feel is abnormal.
5. Braking sound (from EHCU) is heard while not
braking.
These are all attributable to problems which cannot be de-
tected by EHCU self-diagnosis. Use the customer com-
plaint and a test to determine which symptom is present.
Then follow the appropriate flow chart listed below.
NoSymptomDiagnostic Flow ChartsNo.Sym tomWithout TECH 2With TECH 2
1ABS works frequently but vehicle does not decelerate.Chart A–1Chart TA–1
2Uneven braking occurs while ABS works.Chart A–2—
3The wheels are locked.Chart A–3Chart TA–3
4Brake pedal feel is abnormal.Chart A–4—
5Braking sound (from EHCU) is heard while not braking. Chart A–5Chart TA–5
Chart A–1 ABS Works Frequently But Vehicle Does Not Decelerate
StepActionYe sNo
11. Turn key off.
2. G Sensor connector and EHCU connector disconnected.
Is there continuity between EHCU terminals 26 and 8?
Go to Step 2Go to Step 3
2Connect EHCU connector.
Is there continuity between the G sensor and the EHCU?
Go to Step 3
Repair circuit.
Go to Step 1
3Is the G sensor normal? (Refer to chart B-5)
Go to Step 4
Replace G
sensor.
Go to Step 11
4Is braking force distribution normal between the front and rear of
the vehicle?
Go to Step 5
Repair brake
parts.
Go to Step 11
5Are axle parts installed normally?Go to Step 6Repair axle parts.
Go to Step 11
6Is there play in each wheel speed sensor?Repair wheel
speed sensor.
Go to Step 11
Go to Step 7
7Is there damage, or powered iron sticking to each wheel speed
sensor/sensor ring?Replace sensor
or sensor ring.
Go to Step 11
Go to Step 8
8Is the output of each wheel speed sensor normal? (Refer to chart
C-1 or TC-1)
Go to Step 9
Replace wheel
speed sensor or
repair harness.
Go to Step 11
9Is the input of transmission normal? (Refer to chart C-2 or TC-2)
Go to Step 10
Replace switch or
repair harness.
Go to Step 11
