Opel Frontera UBS. Manual - part 2038

5A–32

BRAKE CONTROL SYSTEM

5A–33

BRAKE CONTROL SYSTEM

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.

No

Symptom

Diagnostic Flow Charts

No.

Sym tom

Without TECH 2

With TECH 2

1

ABS works frequently but vehicle does not decelerate.

Chart A–1

Chart TA–1

2

Uneven braking occurs while ABS works.

Chart A–2

—

3

The wheels are locked.

Chart A–3

Chart TA–3

4

Brake pedal feel is abnormal.

Chart A–4

—

5

Braking sound (from EHCU) is heard while not braking. 

Chart A–5

Chart TA–5

Chart A–1 ABS Works Frequently But Vehicle Does Not Decelerate

Step

Action

Yes

No

1

1. Turn key off.
2. G Sensor connector and EHCU connector disconnected.

Is there continuity between EHCU terminals 26 and 8?

Go to Step 2

Go to Step 3

2

Connect EHCU connector.

Is there continuity between the G sensor and the EHCU?

Go to Step 3

Repair circuit.

Go to Step 1

3

Is the G sensor normal? (Refer to chart B-5)

Go to Step 4

Replace G

sensor.

Go to Step 11

4

Is braking force distribution normal between the front and rear of
the vehicle?

Go to Step 5

Repair brake

parts.

Go to Step 11

5

Are axle parts installed normally?

Go to Step 6

Repair axle parts.

Go to Step 11

6

Is there play in each wheel speed sensor?

Repair wheel

speed sensor.

Go to Step 11

Go to Step 7

7

Is 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

8

Is 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

9

Is 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