Opel Frontera UBS. Manual - part 211

5A–57

BRAKE CONTROL SYSTEM

Unit Inspection Procedure

This section describes the following inspection
procedures referred to during “SYMPTOM DIAGNOSIS”
and “DIAGNOSIS BY ‘ABS’ WARNING LIGHT
ILLUMINATION PATTERN” :

without TECH 2

with TECH 2

Wheel Speed Sensor Output Inspection

Chart C-1-1 to C-1-4

Chart TC-1

Transmission SW Inspection

Chart C-2

Chart TC-2

Chart C-1-1 FL Sensor Output Inspection Procedure

Step

Action

Yes

No

1

1. Turn the key off.
2. Disconnect EHCU connector.
3. Jack up the vehicle, With all four wheels off the ground.

Measure the AC voltage between EHCU connector terminals
while turning FL wheel at a speed of 1 RPS:

Is voltage between EHCU connector terminals 20 and 21 under
200 mV?

Go to Step 2

Ok.

Go to Step 3

2

1. Disconnect the wheel speed sensor.
2. Measure resistance between the wheel speed sensor

connector terminals 1 and 2.

Is resistance between connector (C-13) terminals 1 and 2 within
1.3k - 1.9k ohms?

Connector is

faulty, or open or

short circuit in

harness between

wheel speed

sensor connector

and EHCU.

Inspect and

correct the

connector or

harness

Go to Step 3

Wheel speed

sensor is faulty.

Replace the

wheel speed

sensor.

Go to Step 3

3

Reconnect all components and ensure all components are
properly mounted.

Was this step finished?

Repeat the “Basic

diagnostic flow

chart.”

Go to Step 3

5A–58

BRAKE CONTROL SYSTEM

Chart C-1-2 FR Sensor Output Inspection Procedure

Step

Action

Yes

No

1

1. Turn the key off.
2. Disconnect EHCU connector.
3. Jack up the vehicle with all four wheels off the ground.

Measure the AC voltage between EHCU connector terminals
while turning FR wheel at a speed of 1 RPS:

Is voltage between EHCU connector terminals 4 and 5 under 200
mV?

Go to Step 2

Ok.

Go to Step 3

2

1. Disconnect the wheel speed sensor.
2. Measure resistance between the wheel speed sensor

connector terminals 1 and 2.

Is resistance between connector (C-41) terminals 1 and 2 within
1.3k - 1.9k ohms?

Connector is

faulty, or open or

short circuit of

harness between

wheel speed

sensor connector

and EHCU.

Inspect and

correct the

connector or

harness

Go to Step 3

Wheel speed

sensor is faulty.

Replace the

wheel speed

sensor.

Go to Step 3

3

Reconnect all components and ensure all components are
properly mounted.

Was this step finished?

Repeat the “Basic

diagnostic flow

chart.”

Go to Step 3

Chart C-1-3 RL Sensor Output Inspection Procedure

Step

Action

Yes

No

1

1. Turn the key off.
2. Disconnect EHCU connector.
3. Jack up the vehicle with all four wheels off the ground.

Measure the AC voltage between EHCU connector terminals
while turning RL wheel at a speed of 1 RPS:

Is voltage between EHCU connector terminals 22 and 23 under
200 mV?

Go to Step 2

Ok.

Go to Step 3

2

1. Disconnect the wheel speed sensor.
2. Measure resistance between the wheel speed sensor

connector terminals 1 and 2.

Is resistance between connector (F-3) terminals 1 and 2 within
1.3k - 1.9k ohms?

Connector is

faulty, or open or

short circuit of

harness between

wheel speed

sensor connector

and EHCU.

Inspect and

correct the

connector or

harness

Go to Step 3

Wheel speed

sensor is faulty.

Replace the

wheel speed

sensor.

Go to Step 3

3

Reconnect all components and ensure all components are
properly mounted.

Was this step finished?

Repeat the “Basic

diagnostic flow

chart.”

Go to Step 3

5A–59

BRAKE CONTROL SYSTEM

Chart C-1-4 RR Sensor Output Inspection Procedure

Step

Action

Yes

No

1

1. Turn the key off.
2. Disconnect EHCU connector.
3. Jack up the vehicle with all four wheels off the ground.

Measure the AC voltage between EHCU connector terminals
while turning RR wheel at a speed of 1 RPS:

Is voltage between EHCU connector terminals 2 and 3 under 200
mV?

Go to Step 2

Ok.

Go to Step 3

2

1. Disconnect the wheel speed sensor.
2. Measure resistance between the wheel speed sensor

connector terminals 1 and 2.

Is resistance between connector (F-2) terminals 1 and 2 within
1.3k - 1.9k ohms?

Connector is

faulty, or open or

short circuit of

harness between

wheel speed

sensor connector

and EHCU.

Inspect and

correct the

connector or

harness

Go to Step 3

Wheel speed

sensor is faulty.

Replace the

wheel speed

sensor.

Go to Step 3

3

Reconnect all components and ensure all components are
properly mounted.

Was this step finished?

Repeat the “Basic

diagnostic flow

chart.”

Go to Step 3

Chart TC-1 Sensor Output Inspection Procedure (Use TECH 2)

Step

Action

Yes

No

1

1. Connect TECH 2.
2. While driving the vehicle, check the wheel speed of each

sensor by Data List.

Is the vehicle speed value is normal?

Go to Step 6

Go to Step 2

2

Check the sensor harness for suspected disconnection (Check
while shaking harness/connector).

Is the sensor harness connection normal?

Replace speed

sensor.

Go to Step 3

Repair.

Go to Step 6

3

While driving the vehicle, check the wheel speed of each sensor
by Data List.

Is the vehicle speed value is normal?

Go to Step 6

Go to Step 4

4

Check the sensor rotor.

Is the sensor rotor normal?

Go to Step 6

Replace sensor

rotor.

Go to Step 5

5

While driving the vehicle, check the wheel speed of each sensor
by Data List.

Is the vehicle speed value is normal?

Go to Step 6

Repair harness or

connector

between EHCU

and speed

sensor.

Go to Step 6

6

Reconnect all components, ensure all components are properly
mounted.

Was this step finished?

Repeat the “Basic

diagnostic flow

chart.”

Go to Step 6

5A–60

BRAKE CONTROL SYSTEM

Chart C-2 Transmission Input Inspection Procedure

Step

Action

Yes

No

1

1. Turn the key off.
2. Disconnect EHCU connector.

Is there continuity between EHCU connector terminals 6 and 15
(Gear position-P(A/T), N(M/T))?

Shorted switch

harness.

Repair switch or

harness.

Go to Step 6

Go to Step 2

2

Is the vehicle an A/T model?

Go to Step 3

Go to Step 5

3

Turn the key on and measure voltage between EHCU connector
terminals 6 and 15.

Is there less than 6V when the gear position is L, and R(Battery
voltage 12V)?

Go to Step 5

Transmission SW

trouble.

Disconnected

harness.

Repair SW and

harness.

Go to Step 6

4

Turn the key on and measure the voltage between EHCU
connector terminal 6 and 15.

Is there more than 9.6V when the gear position is 1, 2, R(Battery
voltage 12V)?

Go to Step 5

Transmission SW

trouble.

Disconnected

harness.

Repair SW and

harness.

Go to Step 6

5

Measure the voltage between EHCU connector terminals 6 and
15.

Is there 6.6 to 9.0V when the gear position is 3, 4, 5 and N(M/T) or
2,3,D,N and P(A/T)(Battery voltage 12V)?

Go to Step 6

Transmission SW

trouble.

Disconnected

harness.

Repair SW and

harness.

Go to Step 6

6

1. Reconnect all components and ensure all components are

properly mounted.

2. Clear diagnostic trouble code.

Was this step finished?

Repeat the “Basic

diagnostic flow

chart.”

Go to Step 6