1998 OPEL FRONTERA transmission

5A–37 BRAKE CONTROL SYSTEM
StepNo Ye s
Action
5Is front 4WD controller normal?
Replace EHCU.
Go to Step 9
Replace 4WD
controller or
repair harness.
Go to Step 9
6Is transmission input normal? (Chart C-2 or TC-2)
Go to Step 7
Replace SW or
repair harness
Go to Step 9
7Is front 4WD controller normal?
Go to Step 8
Replace 4WD
controller or
repair harness.
Go to Step 9
8Is hydraulic unit grounded properly?Replace EHCU.
Go to Step 9Correct.
Go to Step 9
9Reconnect all components, ensure all components are properly
mounted.
Was this step finished?Repeat the “Basic
diagnostic flow
chart.”
Go to Step 9
Chart A-4 Brake Pedal Feed Is Abnormal
StepActionYe sNo
1Is the stop light actuated when the brake pedal is depressed?Go to Step 2Go to Step 3
21. Turn the ignition switch off.
2. Disconnected EHCU connector.
3. Measure voltage between the EHCU connector terminal 10
and 15 when brake pedal is depressed.
Is the voltage equal to the battery voltage?
Go to Step 4
Harness NG
between brake
SW and EHCU.
Go to Step 7
3Is stop light fuse C-14 normal?
Go to Step 5
Replace fuse
C-14.
Go to Step 7
4Is there continuity between EHCU connector terminals, 12 and 15
to body ground?
Go to Step 6
Repair body
grounded
harness.
Go to Step 7
5Is the brake SW normal?Repair stop light
harness.
Go to Step 7Replace brake
SW.
Go to Step 7
6Is the check harness/connector for suspended disconnection?Hydraulic system
leakage or air
entry (Refer to
servicing
“Leakage or
brake fluid” )
Go to Step 7
Repair harness.
Go to Step 7
7Reconnect all components and ensure all components are
properly mounted.
Was this step finished?Repeat the “Basic
diagnostic flow
chart.”
Go to Step 7

5A–39 BRAKE CONTROL SYSTEM
Diagnostic Trouble Codes
Choose and trace an appropriate flowchart by the
numbers listed below to find fault and repair.
Code
ItemDiagnosisChart No.
12Start CodeNormal—
14EHCU FunctionAbnormality in input/output, operational and
control circuitsB-2
15Power Voltage DropB-3
16CLASS–2 Communication Line Ab-
normalityB-4
21G-sensorWiring disconnectionB-5
23Transmission InputInput abnormalityB-6
24Transfer MonitorB-7
32Motor & Motor RelayShorted or disconnected coilB-8
35Valve RelayShorted or disconnected coil/wiringB-9
41FL Holding Solenoid ValveShorted or disconnected coil/wiringB-10
42FL Decompression Solenoid ValveShorted or disconnected coil/wiringB-11
43FR Holding Solenoid ValveShorted or disconnected coil/wiringB-12
44FR Decompression Solenoid ValveShorted or disconnected coil/wiringB-13
45Rear Holding Solenoid ValveShorted or disconnected coil/wiringB-14
46Rear Decompression Solenoid ValveShorted or disconnected coil/wiringB-15
51FL Wheel Speed SensorDisconnected coil/wiringB-16
52FR Wheel Speed SensorDisconnected coil/wiringB-17
53RL Wheel Speed SensorDisconnected coil/wiringB-18
54RR Wheel Speed SensorDisconnected coil/wiringB-19
61FL Wheel Speed SensorShorted coil/wiringB-20
62FR Wheel Speed SensorShorted coil/wiringB-21
63RL Wheel Speed SensorShorted coil/wiringB-22
64RR Wheel Speed SensorShorted coil/wiringB-23
65Sensor Signal InputWrong number of teethB-24

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–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 2with TECH 2
Wheel Speed Sensor Output InspectionChart C-1-1 to C-1-4Chart TC-1
Transmission SW InspectionChart C-2Chart TC-2
Chart C-1-1 FL Sensor Output Inspection Procedure
StepActionYe sNo
11. 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
21. 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
3Reconnect all components and ensure all components are
properly mounted.
Was this step finished?Repeat the “Basic
diagnostic flow
chart.”
Go to Step 3

5A–60
BRAKE CONTROL SYSTEM
Chart C-2 Transmission Input Inspection Procedure
StepActionYe sNo
11. 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
2Is the vehicle an A/T model?Go to Step 3Go to Step 5
3Turn 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
4Turn 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
5Measure 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
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

5A–61 BRAKE CONTROL SYSTEM
Chart TC-2 Transmission Input Inspection Procedure (Use TECH 2)
StepActionYe sNo
11. Connect TECH 2.
2. Select Data List.
Is this vehicle an A/T model ?
Go to Step 2Go to Step 4
2Is “Off-Road Switch(Transmission Input): Active” when the shift
lever is the L and R?
Go to Step 3Go to Step 6
3Is “Off-Road Switch(Transmission Input): Inactive” when the shift
lever is other than the L and R?
Go to Step 7Go to Step 6
4Is “Off-Road Switch(Transmission Input): Active” when the shift
lever is in 1, 2 and R?
Go to Step 5Go to Step 6
5Is “Off-Road Switch(Transmission Input): Inactive” when the shift
lever is other than the 1, 2 and R?
Go to Step 7Go to Step 6
61. Abnormal T/M SW, inhibitor SW, or harness.
2. Repair T/M SW, inhibitor SW, or harness.
Is the T/M SW, inhibitor SW, or harness repaired?
Go to Step 7Go to Step 6
7Reconnect all components, ensure all components are properly
mounted.
Was this step finished?Repeat the “Basic
diagnostic flow
chart.”
Go to Step 7

6A–13
ENGINE MECHANICAL
Condition CorrectionPossible cause
Engine knockingPreignition due to use of spark plugs
of inadequate heat rangeInstall Spark Plugs of adequate heat
range
Carbon deposits in combustion
chambersClean
Fuel too low in octane ratingReplace fuel
Wide Open Throttle enrichment
system failureRefer to Section 6E
Selection of transmission gear
incorrectCaution operator of incorrect gear
selection
Engine overheatingRefer to “Engine Lacks Power”
OthersWater pump defectiveReplace
Drive belt slippingReplace auto tentioner or drive belt
Abnormal Combustion
ConditionPossible causeCorrection
Trouble in fuel systemFuel pressure control valve defectiveReplace
Fuel filter cloggedReplace
Fuel pump cloggedClean or replace
Fuel tank or fuel pipe cloggedClean or replace
Fuel injector cloggedClean or replace
Fuel pump relay defectiveReplace
Power supply cable for fuel pump
broken or poor connectionsReconnect, correct or replace
Mass Airflow (MAF) sensor circuit
open or defectiveCorrect or replace
MAF Sensor defectiveReplace
Manifold Absolute Pressure Sensor
circuit open or shortedCorrect or replace
Manifold Absolute Pressure Sensor
defectiveReplace
Engine Coolant Temperature (ECT)
Sensor circuit open or shortedCorrect or replace
ECT Sensor defectiveReplace
Throttle Position Sensor adjustment
incorrectReadjust
Throttle Position Sensor defectiveReplace
Throttle Position Sensor connector
poor connectionsReconnect
Vehicle Speed Sensor cable poor
connections or defectiveCorrect or replace
Vehicle Speed Sensor loosely fixedFix tightly
Vehicle Speed Sensor in wrong
contact or defectiveReplace
Powertrain Control Module cable
poor connections or defectiveCorrect or replace

6A–14
ENGINE MECHANICAL
Condition CorrectionPossible cause
Trouble in emission control systemHeated Oxygen Sensor circuit openCorrect or replace
Heated Oxygen Sensor defectiveReplace
Signal vacuum hose loosely fitted or
defectiveCorrect or replace
EGR Valve circuit open or shortedCorrect or replace
Exhaust Gas Recirculation Valve
defectiveReplace
ECT Sensor circuit open or shortedCorrect or replace
Canister Purge Valve circuit open or
shortedCorrect or replace
Canister Purge Valve defectiveReplace
ECT Sensor defectiveReplace
Positive Crankcase Ventilation
(PCV) valve and hose cloggedCorrect or replace
Evaporator systemRefer to Section 6E
Trouble in ignition system————Refer to “Engine Lacks Power”
Trouble in cylinder head partsCarbon deposits in combustion
chamberRemove carbon
Carbon deposit on valve, valve seat
and valve guideRemove carbon
Engine Oil Consumption Excessive
ConditionPossible causeCorrection
Oil leakingOil pan drain plug looseRetighten or replace gasket
Crankcase fixing bolts loosenedRetighten
Oil pan setting bolts loosenedRetighten
Oil pan gasket brokenReplace gasket
Front cover retaining bolts loose or
gasket brokenRetighten or replace gasket
Head cover fixing bolts loose or
gasket brokenRetighten or replace gasket
Oil cooler adapter crackedReplace
Oil cooler center bolt looseRetighten
Oil cooler O–ring brokenReplace
Oil cooler piping loose or brokenRetighten or replace
Oil filter adapter crackedReplace
Oil filter attaching bolt loose or rubber
gasket brokenRetighten or replace oil filter
Oil cooler brokenReplace
Crankshaft front or rear oil seal
defectiveReplace oil seal
Oil pressure unit loose or brokenRetighten or replace
Blow–by gas hose brokenReplace hose
Positive Crankcase Ventilation Valve
cloggedClean
Engine/Transmission coupling failedReplace oil seal