display MITSUBISHI LANCER EVOLUTION IV 1998 Workshop Manual

MPI – Troubleshooting13-26
7. INSPECTION PROCEDURE USING
OSCILLOSCOPE
7-1 AIR FLOW SENSOR (AFS)
Observing waveforms displayed on the oscilloscope allows
you to visually identify possible unusual disturbances in
waveform that could temporarily occur in the air flow sensor
output.

(1) Disconnect the air flow sensor connector and connect
the special tool (Test Harness: MB991709) to it. (Ensure
that all terminals are connected.)
(2) Connect the oscilloscope probe to terminal no. 3 of air
flow sensor connector.
NOTE
If the engine ECU connector is used, connect the
oscilloscope probe to terminal no. 90.
(3) Perform the same steps from here on as with the 4G9
engine.
7-2 CAMSHAFT POSITION SENSOR AND CRANK
ANGLE SENSOR
Perform the same steps as with the conventional 4G9 engine
for the inspection.
7-3 INJECTOR
Observing waveforms displayed on the oscilloscope allows
you to visually check the conditions of injector drive signals
actually output from the engine ECU.
Injector Control Signal (Oscilloscope 1)

(1) Disconnect the injector connector and connect the special
tool (Test Harness: MB991348) to the circuit. (Ensure
that the terminals on both the power supply and engine
ECU sides are connected.)
(2) Connect the oscilloscope probe to terminal no. 2 of injector
connector.
NOTE
If the engine ECU connector is used for the measurement,
take measurements at each of the following terminals.
Connect the oscilloscope probe to terminal no. 1 when
the waveform is observed with no. 1 cylinder, to terminal
no. 14 when the waveform is observed with no. 2 cylinder,
to terminal no. 2 when the waveform is observed with
no. 3 cylinder, and to terminal no. 15 when the waveform
is observed with no. 4 cylinder.
Oscilloscope
Oscilloscope

REAR AXLE – Special Tools27-3
SPECIAL TOOLS
ToolNumberNameUse
MB991529Diagnosis code
check harnessInspection of AYC (diagnosis display by AYC
warning lamp)
MD998330
(MD998331)Oil pressure
gauge
(2,942 kPa
{30 kgf/cm
2})
Hydraulic pressure measurement with AYC>
MB991705Hose adapter
MB990925Bearing & oil seal
installer setPressfitting of oil seal
MB991115Oil seal installerPressfitting of oil seal (used in
combination with MB990938)
MD998812Installer capPressfitting of oil seal nism of vehicles with AYC>
MD998813Installer 100
MD998829Installer adapter
(60)
MB990767End yoke holderFixing of hub

ABS – TroubleshootingABS – Troubleshooting35B-6
Code No. 27: AYC monitor system (defective AYC)Probable cause
This code is output when the AYC monitor signal becomes faulty.
Defective AYC-ECU

Defective ABS-ECU

Defective harness or connector
OK
Replace the ABS-ECU.
OK
MUT-II data list
AYC signal
OKOFF to be displayed when the
engine runs at idle with the
vehicle stationary.NGReplace AYC-ECU.
OK
Check the harness between ABS-ECU
and AYC-ECU.NG
Repair
Check the following connectors:
B-25, B-96NG
Repair
Code No. 32: Acceleration sensor (longitudinal accelera-
tion) circuit systemProbable cause
This code is output under either of the following conditions:

The output from the acceleration sensor (longitudinal acceleration) becomes 0.5
V or less, or 4.5 V or more.

The acceleration sensor (longitudinal acceleration) harness is open- or
short-circuited.
Defective acceleration sensor (longitudinal accelera-
tion)

Defective harness or connector

Defective ABS-ECU
OK
Check the trouble symptom.NGReplace ABS-ECU.
OK
Check the trouble symptom.NGCheck and repair the harness between
acceleration sensor (longitudinal
acceleration) and ABS-ECU.
OK
Check the trouble symptom.NGCheck and repair the harness between
general-purpose fuse No. 6 and
acceleration sensor (longitudinal
acceleration).
OK
Replace ABS-ECU.
OK
Check the following connector:
B-24NG
Repair
OK
Measure at B-24 ABS-ECU connector.

Connect the connector.

Ignition switch: ON

Voltage across 4 and 17
OK:2.4 – 2.6 V
(horizontal position)NGCheck the following connectors:
B-24, D-20, B-52NG
Repair
NG
Check the harness between accelera-
tion sensor (longitudinal acceleration)
and ABS-ECU.NG
Repair
OK
Check the trouble symptom.
OK
Check the valve relay.NG
Replace
(1) NGCheck the following connectors:
D-20, B-49, B-75NG
Repair
Check the following connector:
D-20, B-49, B-75NG
Repair
(2) NG
Measure at D-20 acceleration sensor
(longitudinal acceleration) connector.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON
(1) Voltage across 1 and body ground
OK:Battery voltage
(2) Continuity across 3 and body
ground
OK:Conducting

ABS – Troubleshooting35B-14
INSPECTION PROCEDURE 4
When the ignition key is turned to “START”, the ABS
warning lamp does not illuminate.
Probable cause
The ABS-ECU is powered through IG2 which is turned off when the ignition key
is in START position. The ABS warning lamp is powered through IG1 which is not
turned off even when the ignition key is in START position. So the cause must be
a defective circuit on valve relay side.
Malfunction of wiring harness or connector

Malfunction of valve relay
OK
Check the trouble symptom.NGCheck the harness between the com-
bination meter and valve relay, and
repair if necessary.
OK
Check the motor for operation.NGCheck the harness between the valve
relay and ground, and repair if neces-
sary.
OK
Check the following connector:
A-76NG
Repair
OK
Measure at valve relay connector A-76.

Disconnect the connector and
measure at the harness side.

Disconnect ABS-ECU connector
B-25.

Ignition switch: ON

Voltage between 3 and body
ground
OK:Battery voltageNGCheck the following connectors
and diode:
A-76, B-26NG
Repair
ABS valve relay check.NGReplace the valve relay.
INSPECTION PROCEDURE 5
Brake operation is abnormal
Probable cause
The varies depending on the driving conditions and the road surface conditions, so
problem diagnosis is difficult. However, if a normal diagnosis code is displayed, carry
out the following inspection.
Improper installation of wheel speed sensor

Incorrect sensor harness contact

Foreign material adhering to wheel speed sensor

Malfunction of wheel speed sensor

Malfunction of wheel bearing

Malfunction of hydraulic unit

Malfunction of ABS-ECU
NG
Repair
Hydraulic unit checkOKWheel speed sensor inspection. [Refer to Inspection Procedure
for “when either of diagnosis codes No. 11 to 14 is output” (P.35B-3).]

CHASSIS ELECTRICAL – Ignition Switch and Immobilizer System54-13
IGNITION SWITCH AND IMMOBILIZER SYSTEM

SPECIAL TOOL
ToolNumberNameUse
MB991502MUT-II sub
assembly
Immobilizer system check
(Diagnosis display using the MUT-II)

Registration of the ID code
TROUBLESHOOTING
Caution
The ID code should always be re-registered when replacing the immobilizer-ECU.
STANDARD FLOW OF DIAGNOSIS TROUBLESHOOTING
Refer to GROUP 00 – How To Use Troubleshooting/Inspection Service Points.
DIAGNOSIS FUNCTION
DIAGNOSIS CODES CHECK
Refer to GROUP 00 – How To Use Troubleshooting/Inspection Service Points.
ERASING DIAGNOSIS CODES
Refer to GROUP 00 – How To Use Troubleshooting/Inspection Service Points.
Caution
The diagnosis codes which result from disconnecting the battery cables cannot be erased.
INSPECTION CHART FOR DIAGNOSIS CODES
Diagnosis code No.Inspection itemsReference
page
11Transponder communication system54-14
12*ID code are not the same or are not registered54-14
21Communication system between MUT-II and engine-ECU54-15
31EEPROM abnormality inside immobilizer-ECU54-15
NOTE
*: Diagnosis code No. 12 is not recorded.

CHASSIS ELECTRICAL – Ignition Switch and Immobilizer System54-21
ID CODE REGISTRATION METHOD
If using an ignition key that has just been newly purchased,
or if the immobilizer-ECU has been replaced, you will need
to register the ID codes for each ignition key being used
into the immobilizer-ECU. (A maximum of eight different ID
codes can be registered.)
Moreover, when the immobilizer-ECU has been replaced, you
will need to use the MUT-II to register the password that
the user specifies into the immobilizer-ECU. (Refer to the
MUT-II instruction manual for instructions on using the MUT-II.)
Caution
If registering of the ID codes is carried out all
previously-registered codes will be erased. Accordingly,
you should have ready all of the ignition keys that have
already been registered.
1. Connect the MUT-II to the diagnosis connector.
Caution
Turn the ignition switch off before connecting or
disconnecting the MUT-II.
2. Check that the diagnosis code No.54 is not displayed
for MPI system. If the code is displayed, carry out
troubleshooting before proceeding to the next step. (Refer
to GROUP 13A – Troubleshooting).
3. Use the ignition key that is to be registered to turn the
ignition switch to the ON position.
4. Use the MUT-II to register the ID code. If you are
registering two or more codes, use the next key to be
registered to turn the ignition switch to the ON position
without disconnecting the MUT-II.
5. Disconnect the MUT-II. This completes the registration
operation.
6. Check that the engine can be started by each one of
the ignition keys.
7. Check that the diagnosis code No.54 is not displayed
for MPI system. If the code is displayed, erase it. (Refer
to GROUP 13A – Troubleshooting).
MUT-II