1998 OPEL FRONTERA key

5A–44
BRAKE CONTROL SYSTEM
Chart B-3 Power Voltage Drop (DTC 15)
StepActionYe sNo
1Is the battery voltage normal? (Battery capacity check)
Go to Step 2
Charge or
replace battery.
Go to Step 2
21. Turn the key off.
2. Disconnect EHCU connector.
3. Turn the key on.
Is the voltage between EHCU connector terminals 8 and 15,
higher than 10V?Check harness
connector for
suspected
disconnection.
Fault found:
Repair, and
perform system
self-check.
No fault found:
replace EHCU.
Go to Step 3
Repair harness or
connector.
Go to Step 3
31. Reconnect all components, ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat the “Basic
diagnostic flow
chart.”
Go to Step 3
Chart B-4 CLASS-2 Communication Line Abnormality (DTC 16)
StepActionYe sNo
11. Turn the key off.
2. Disconnect EHCU and PCM connector.
Is there continuity between EHCU connector terminals 25 and
ground?
Go to Step 2
Repair harness or
connector.
Go to Step 3
21. Connect EHCU connector.
2. Clear diagnostic trouble code.
3. Turn the key on.
Is the diagnostic trouble code 16 shown on the displayed?Check the PCM
harness. Refer to
6E section.
Go to Step 3
Replace EHCU.
Go to Step 3
31. Reconnect all components, ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat the “Basic
diagnostic flow
chart.”
Go to Step 3

5A–46
BRAKE CONTROL SYSTEM
Chart B-6 Abnormal Transmission Input (DTC 23)
StepActionYe sNo
11. Turn the key off.
2. Disconnect EHCU connector.
Is there continuity between EHCU connector terminal 6 to 15
(Gear position-P(A/T), N(M/T))?Shorted switch
harness.
Repair switch or
harness.
Go to Step 6
Go to Step 2
2Is the vehicle an A/T model?Go to Step 3Go to Step 4
3Turn the key on and measure the voltage between EHCU
connector terminal 6 and 15.
Is the 6V under 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
4Turn the key on and measure the voltage between EHCU
connector terminal 6 and 15.
Is the 9.6V over 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
5Is 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)?Suspected
harness/
connector short
power
source/GND.
Suspected
shorted
transmission SW.
Fault found:
repair, and
perform system
self-check.
No fault found:
replace EHCU.
Go to Step 6
Transmission SW
trouble.
Disconnected
harness.
Repair SW and
harness.
Go to Step 6
61. Reconnect all components, 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

5A–47 BRAKE CONTROL SYSTEM
Chart B-7 Transfer Monitor (DTC 24)
StepActionYe sNo
11. Turn the key off.
2. Disconnect EHCU connector.
Is the EHCU connector terminal 9 line normally?
Go to Step 2
Repair
Go to Step 3
2Is the TOD ECU or 4WD controller normal?
Replace EHCU.
Go to Step 3
Repair or replace
TOD ECU or
4WD contrder.
Go to Step 3
31. Reconnect all components, ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat the “Basic
diagnostic flow
chart.”
Go to Step 3
Chart B-8 EHCU Pump Motor And Motor Relay Circuit (DTC 32)
StepActionYe sNo
11. Turn the key off.
2. Disconnect EHCU connector.
3. Measure voltage between EHCU connector terminal 13 and
body ground.
Is the voltage equal to battery voltage?
Go to Step 2
Repair
fuse/harness
between battery
and EHCU
connector
terminal 13.
Go to Step 3
2Is there continuity between EHCU connector terminal 12 and
ground?
Go to Step 3
Repair between
EHCU connector
terminal 12 and
ground.
Go to Step 3
31. 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 3
Chart B-9 EHCU Pump Valve And Valve Relay Circuit (DTC 35)
StepActionYe sNo
11. Turn the key off.
2. Disconnect EHCU connector.
3. Measure voltage between EHCU connector terminal 14 and
body ground.
Is the voltage equal to battery voltage?
Replace EHCU.
Go to Step 2
Repair fuse and
harness EHCU
connector
terminal 14 and
battery.
Go to Step 2
21. 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 2

5A–50
BRAKE CONTROL SYSTEM
Chart B-16 FL Speed Sensor Disconnection (DTC 51)
StepActionYe sNo
11. Turn the key off.
2. Disconnect EHCU connector.
3. Measure the resistance between EHCU connector terminals
20 and 21.
Is the resistance between 1.3k and 1.9k ohms?Check for faults
in harness
between speed
sensor and
EHCU.
Fault found:
Repair, and
perform system
self-check.
No fault found:
Replace EHCU.
Go to Step 3
Go to Step 2
2Measure the FL speed sensor resistance at the sensor connector.
Is the resistance between 1.3k and 1.9k ohms?Repair harness
abnormality
between sensors
and EHCU.
Go to Step 3
Replace sensor.
Go to Step 3
31. Reconnect all components, ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat the “Basic
diagnostic flow
chart.”
Go to Step 3
Chart B-17 FR Speed Sensor Disconnection (DTC 52)
StepActionYe sNo
11. Turn the key off.
2. Disconnect EHCU connector.
3. Measure the resistance between EHCU connector terminals 4
and 5.
Is the resistance between 1.3k and 1.9k ohms?Check for faults
in harness
between speed
sensor and
EHCU.
Fault found:
Repair, and
perform system
self-check.
No fault found:
Replace EHCU.
Go to Step 3
Go to Step 2
2Measure the FR speed sensor resistance at the sensor
connector.
Is the resistance between 1.3k and 1.9k ohms?Repair harness
abnormality
between sensors
and EHCU.
Go to Step 3
Replace sensor.
Go to Step 3
31. 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 3

5A–51 BRAKE CONTROL SYSTEM
Chart B-18 RL Speed Sensor Disconnection (DTC 53)
StepActionYe sNo
11. Turn the key off.
2. Disconnect EHCU connector.
3. Measure the resistance between EHCU connector terminals
22 and 23.
Is the resistance between 1.3k and 1.9k ohms?Check for faults
in harness
between speed
sensor and
EHCU.
Fault found:
Repair, and
perform system
self-check.
No fault found:
Replace EHCU.
Go to Step 3
Go to Step 2
2Measure the RL speed sensor resistance at the sensor
connector.
Is the resistance between 1.3k and 1.9k ohms?Repair harness
abnormality
between sensors
and EHCU.
Go to Step 3
Replace sensor.
Go to Step 3
31. 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 3
Chart B-19 RR Speed Sensor Disconnection (DTC 54)
StepActionYe sNo
11. Turn the key off.
2. Disconnect EHCU connector.
3. Measure the resistance between EHCU connector terminals 2
and 3.
Is the resistance between 1.3K and 1.9k ohms?Check for faults
in harness
between speed
sensor and
EHCU.
Fault found:
Repair, and
perform system
self-check.
No fault found:
Replace EHCU.
Go to Step 3.
Go to Step 2
2Measure the RR speed sensor resistance at the sensor
connector.
Is the sensor resistance between 1.3k and 1.9k ohms?Repair harness
abnormality
between sensors
and EHCU.
Go to Step 3
Replace sensor.
Go to Step 3
31. 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 3

5A–52
BRAKE CONTROL SYSTEM
Chart B-20 FL Speed Sensor Short Circuit (DTC 61)
StepActionYe sNo
11. Turn the key off.
2. Disconnect EHCU connector
3. Measure the FL speed sensor resistance between EHCU
connector terminals 20 and 21.
Is the resistance between 1.3k and 1.9k ohms?
Go to Step 2Go to Step 3
2Is there play in the sensor/sensor rotor?
Go to Step 4
Repair.
Go to Step 6
3Measure the FL speed sensor resistance at the sensor connector.
Is the resistance between 1.3k and 1.9k ohms?Repair harness
abnormality
between sensors
and EHCU.
Go to Step 6
Replace sensor.
Go to Step 6
4Damage and powdered iron sticking to sensor/sensor ring?
Go to Step 5
Repair.
Go to Step 6
5Is sensor output normal? (Chart C-1-1 or TC-1)Check for faults
in harness
between speed
sensor and
EHCU.
Fault found:
repair, and
perform system
self-check.
No fault found:
replace EHCU.
Go to Step 6
Replace sensor.
Go to Step 6
61. 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
NOTE: Even after repairing the faulty part the warning
light (W/L) does not go out if the vehicle is at a stop. Turn
the ignition switch to the ON position and drive the vehicle
at 12 km/h or higher to make sure that the warning light
goes out.

5A–53 BRAKE CONTROL SYSTEM
Chart B-21 FR Speed Sensor Short Circuit (DTC 62)
StepActionYe sNo
11. Turn the key off.
2. Disconnect EHCU connector.
3. Measure the FR speed sensor resistance between EHCU
connector terminals 4 and 5.
Is the resistance between 1.3k and 1.9k ohms?
Go to Step 2Go to Step 3
2Is there play in the sensor/sensor rotor?
Go to Step 4
Repair.
Go to Step 6
3Measure the FR speed sensor resistance at the sensor
connector.
Is the resistance between 1.3k and 1.9k ohms?Repair harness
abnormality
between sensors
and EHCU.
Go to Step 6
Replace sensor.
Go to Step 6
4Damage and powdered iron sticking to sensor/sensor ring?
Go to Step 5
Repair.
Go to Step 6
5Is sensor output normal? (Chart C-1-2 or TC-1)Check for faults
in harness
between speed
sensor and
EHCU.
Fault found:
repair, and
perform system
self-check.
No fault found:
replace EHCU.
Go to Step 6
Replace sensor.
Go to Step 6
61. Reconnect all components and ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat “Basic
diagnostic flow
chart.”
Go to Step 6
NOTE: Even after repairing the faulty part the warning
light (W/L) does not go out if the vehicle is at a stop. Turn
the ignition switch to the ON position and drive the vehicle
at 12 km/h or higher to make sure that the warning light
goes out.

5A–54
BRAKE CONTROL SYSTEM
Chart B-22 RL Speed Sensor Short Circuit (DTC 63)
StepActionYe sNo
11. Turn the key off.
2. Disconnect EHCU connector
3. Measure the RL speed sensor resistance between EHCU
connector terminals 22 and 23.
Is the resistance between 1.3k and 1.9k ohms?
Go to Step 2Go to Step 3
2Is there play in the sensor/sensor rotor?
Go to Step 4
Repair.
Go to Step 6
3Measure the RL speed sensor resistance at the sensor
connector.
Is the resistance between 1.3k and 1.9k ohms?Repair harness
abnormality
between sensors
and EHCU.
Go to Step 6
Replace sensor.
Go to Step 6
4Damage and powdered iron sticking to sensor/sensor ring?
Go to Step 5
Repair.
Go to Step 6
5Is sensor output normal? (Chart C-1-3 or TC-1)?Check for faults
in harness
between speed
sensor and
EHCU.
Fault found:
repair, and
perform system
self-check.
No fault found:
replace EHCU.
Go to Step 6
Replace sensor.
Go to Step 6
61. 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
NOTE: Even after repairing the faulty part the warning
light (W/L) does not go out if the vehicle is at a stop. Turn
the ignition switch to the ON position and drive the vehicle
at 12 km/h or higher to make sure that the warning light
goes out.