Page 466 of 2053

1F2 -- 48 M161 ENGINE CONTROLS
D AEW OO M Y_2000
Failure
CodeDescriptionTrouble AreaMaintenance Hint
77No. 3 injector short
circuit to ground or open
When malfunction of injector
circuit
Injector #3 short circuit to
ground or openDInspection the ECM pin 65 about short
circuit or open with bad contact
DInspection the injector
DInspection the ECM
78No. 4 injector short
circuit to battery
When malfunction of injector
circuit
Injector #4 short circuit to
powerDInspection the power to injector #4 or
bad contact
DInspection the injector
DInspection the ECM
79No. 4 injector short
circuit to ground or open
When malfunction of injector
circuit
Injector #4 short circuit to
ground or openDInspection the ECM pin 66 about short
circuit or open with bad contact
DInspection the injector
DInspection the ECM
YAA1F420YAA1F430
Injector Spray Pattern Check
1. Turn the ignition switch OFF.
2. Remove the fuel injector connectors.
3. Remove the fuel distributor and injector with a unit. At this time, do not remove the supply and return line.
Notice:Prepare the beaker for taking the fuel.
4. Connect the shop made cable to the injector with a firing order.
5. Connect the other end of shop made cable to the positive battery cable and negative battery cable.
6. Turn the ignition switch ON.
7. Check the injector for normal spray pattern as shown in the figure. Check injector for leaks or later drop
Injector Resistance Inspection
1. Turn the ignition switch OFF.
2. Remove the fuel injector connectors.
3. Measure the fuel injector coil resistance using a multimeter.
Specified Value
14 ~ 17Ω
Notice:Replace the fuel injector if the measured value is out of the specified values. Check the connector and wire
connection between the ECM and the injector if the measured values are normal.
Page 469 of 2053

M161 ENGINE CONTROLS 1F2 -- 51
D AEW OO M Y_2000
KAB1F230
Failure
CodeDescriptionTrouble AreaMaintenance Hint
40Purge control valve
short circuit to batteryWhen short circuit to power
sourceDInspection the ECM pin 34 about short
circuitoropenwithbadcontact
41
Purge control valve
short circuit to ground or
openWhen short circuit to ground or
open
circuitor open withbadcontact
DInspection the source power of valve
DInspection the purge control solenoid
vale
54Purge control circuit
malfunctionWhen malfunction of purge
control : not workvale
DInspection the ECM
Test
YAA1F460
1. Maintain the normal temperature and idling state by
operating the engine.
2. Connect the ECM terminal No. 11 and No. 34 and
check for normal operation through the output waves
using oscilloscope.Notice:Test during purge control valve operation after
the minimum of 1 minute after the engine turned on.
3. Connect the ECM terminal No. 34 and No.10 and
check for current consumption during the ignition
switch ON.
Specified Value
0.3 ~ 0.5 A
4. Remove the line to canister and measure the pres-
sure with the vacuum pressure gauge.
Specified Value
> 500 mbar
(after approx. 1 min.)
purge control valve operates
at this time
Notice:Test while at normal temperature and at idling
state by operating the engine.
Page 471 of 2053

M161 ENGINE CONTROLS 1F2 -- 53
D AEW OO M Y_2000
Fuel Pressure Test
Tools Required
103 589 00 21 00 Fuel Pressure Gauge
1. Turn the ignition switch to “OFF” position.
2. Remove the fuel pressure test connector.
YAA1F700
3. Connect the fuel pressure gauge to the fuel pressure test connector.
4. Test the fuel pressure at idling by operating the engine using the fuel pressure gauge 103 589 00 21 00.
Vacuum Hose Connected (bar)
3.2~3.6
Vacuum Hose Disconnected (bar)3.7~4.2
5. Replace the pressure regulator diaphragm if out of the specification.
Internal Leakage Test
1. Connect the fuel pressure gauge 103 589 00 21 00 to
the fuel pressure test connector.
YAA1F0K0
2. Stop the engine for approximately 30 minutes and then check the fuel pressure changes.
Pressure change
Fuel pressure drops slowlyDFuel leakage at the injector
DFaulty fuel pressure regulator ’s diaphragm and O-ring
Fuel pressure drops rapidlyDFaulty check valve in the fuel pump
3. If there is no change in fuel pressure and maintain the following pressure over 30minutes, it is normal.
Fuel pressure (bar)
≥2.5
Page 476 of 2053

1F2 -- 58 M161 ENGINE CONTROLS
D AEW OO M Y_2000
Failure
CodeDescriptionTrouble AreaMaintenance Hint
126
Throttle position sensor
1 not plausible with
Throttle position sensor
2
When difference between
TPS 1 and TPS 2DMonitoring the actual values through
scan tool
DIns
pection the ECMpin 84, 85, 87,
127High permanent throttle
signalWhen failure of wiring
harness or actuator
DInspectiontheECMpin84,85,87,
112, 67, 68 about short circuit or open
with bad contact
Itiththttlltt
185
Mass air flow sensor
and throttle position
sensor failureWhen difference between
MAF and TPS signal
DInspection the throttle valve actuator
DInspection the ECM
Circuit Description
The ECM supplies a 5 volt reference signal and a ground to the TP sensor. The TP sensor sends a voltage signal back
to the ECM relative to the throttle plate opening. The voltage signalwill vary from approximately 0.3 ~ 0.9 volts at
closed throttle, to over 4.0 ~ 4.6 volts at Wide Open Throttle (WOT).
The TP sensors serve for engine load control according to the drive pedal command. Load adjustments independent of
the drive pedal command can be implemented; such functions are, for instance, idle control, speed control, drive slip
control, load shock damping, and similar functions.
When the actuator current fails, the throttle valve is returned to emergency operating position by a spring. The throttle
valve position, thereby the actuator drive position checkback is provided by two potentiometers. The motor positions
the throttle valve against the return spring force. Motor and return spring are two separate energy sources. Each of
them is able to position the throttle valve in emergency position alone. Throttle valve position checkback and monitor-
ing is provided by two actual value potentiometers connected to the engine control electronics.
Throttle Actuator Inspection
1. Turn the ignition switch to “ON” position.
2. Measure the TPS 1 signal voltage at the ECM pin No. 87 and TPS 2 signal voltage at the ECM pin No. 85.
Pedal PositionSpecified Value
TPS1Closed0.3 ~ 0.9 vTPS1Opened4.0 ~ 4.6 v
TPS2Closed4.0 ~ 4.6 vTPS2Opened0.3 ~ 0.9 v
Throttle Actuator DC Motor Inspection
1. Turn the ignition switch to “ON” position.
2. Measure the signal voltage between the ECM pin No. 67 and No. 68.
Application
Specified Value
Ignition “ON”0.8 ~ 2.3 v
Engine StatusIdling1.0 ~ 2.5 v
(Coolant temperature is over 70°C)
Throttle Actuator DC Motor Resistance
1. Turn the ignition switch to “OFF” position.
2. Measure the resistance between the ECM pin No. 67 and No. 68.
Specified Value
<10Ω
Page 488 of 2053

1F2 -- 70 M161 ENGINE CONTROLS
D AEW OO M Y_2000
Acceleration Pedal Position Sensor 1 Inspection
1. Turn the ignition switch to “ON” position.
2. Measure the signal voltage between the ECM pin No. 47 and No. 31 while operating the accelerator pedal as follow-
ing conditions.
DNot depress the pedal (closed throttle position)
DFully depress the pedal (full throttle with kick down)
Condition of Throttle Valve
Specified Value (V)
Closed Throttle Valve0.3 ~ 0.7
Fully Depressed Throttle Valve4.3 ~ 4.8
Notice:If measured value is not within the specified value, check the pedal valve sensor and the supply voltage to
APP 1 sensor.
Acceleration Pedal Position Sensor 2 Inspection
1. Turn the ignition switch to “ON” position.
2. Measure the signal voltage between the ECM pin No. 48 and No. 50 while operating the accelerator pedal as follow-
ing conditions.
DNot depress the pedal (closed throttle position)
DFully depress the pedal (full throttle with kick down)
Condition of Throttle Valve
Specified Value (V)
Closed Throttle Valve0.1 ~ 0.4
Fully Depressed Throttle Valve2.1 ~ 2.5
Notice:If measured value is not within the specified value, check the pedal valve sensor and the supply voltage to
APP sensor 2.
Page 508 of 2053
1F2 -- 90 M161 ENGINE CONTROLS
D AEW OO M Y_2000
INTERNAL FAILURE
Failure
CodeDescriptionTrouble AreaMaintenance Hint
21Transmission coding
failureWhen faulty of variant coding
of transmission
DInspection the coding condition
through scan tool
DInspection the Engine Control Module
(ECM)
DInspection the CAN line
DInspection the TCM
136ECM failure (RAM)
When malfunction of random
access memory -- ECM
internal error
DInspection the ECM
142Uncoded/ unprogramed
ECMWhen malfunction of ECM
coding-- required ECM
encoding
DFulfill the ECM variant coding
137ECM failure (EPROM)
143
ECM failure
(EEPROM/Flash -- EPPOM
checksum failure)
144ECM failure (coding ID
checksum failure)When malfunction of ECM
internalDInspection the ECM
145ECM failure (coding
checksum failure)
146ECM failure (programming
checksum failure)
Page 514 of 2053

1F2 -- 96 M161 ENGINE CONTROLS
D AEW OO M Y_2000
YAA1F550
8. Using the fuel tank cap wrench 661 589 00 46 00,
remove the locking cap.
9. Remove the pump from the fuel tank.
Notice:Check the condition of the seal and replace if
necessary. Drain the fuel before removing the pump.
10. Perform an operational check of the fuel pump.
11. Installation should follow the removal procedure in
the reverse order.
YAA1F190
FUEL FILTER
Removal and Installation Procedure
1. Disconnect the negative battery cable.
Caution: The fuel system is under pressure. To
avoid fuel spillage and the risk of personal injury or
fire, it is necessary to relieve the fuel system pres -
sure before disconnecting the fuel lines.
2. Relieve the fuel system pressure. Refer to “Dis-
charging the Pressure in Fuel System” in this sec-
tion.
3. Disconnect the fuel lines from the fuel filter.
Installation Notice
Tightening Torque
28 NSm (21 lb-ft)
4. Remove the fuel filter mounting bracket bolt .
Installation Notice
Tightening Torque
6NSm (53 lb-in)
Notice:Place the fuel pump pad. There may be a corro-
sion due to the contact between the fuel filter and the
bracket.
5. Remove the fuel filter.
6. Install the fuel filter.
7. Perform a leak test of the fuel filter.
8. Installation should follow the removal procedure in
the reverse order.
Page 517 of 2053

M161 ENGINE CONTROLS 1F2 -- 99
D AEW OO M Y_2000
YAA1F710
FUEL RAIL AND INJECTORS
Removal and Installation Procedure
Caution: The fuel system is under pressure. To
avoid fuel spillage and the risk of personal injury or
fire, it is necessary to relieve the fuel system pres -
sure before disconnecting the fuel lines.
1. Discharge the fuel pressure from the fuel pressure
test connector.
2. Disconnect the negative battery cable.
3. Disconnect the vacuum hose from the fuel pressure
regulator.
YAA1F740
4. Remove the cable guide.
5. Disconnect the Hot Film Air Mass (HFM) sensor
connector.
6. Remove the intake air duct mounting bolts.
Installation Notice
Tightening Torque
9NSm (80 Ib-in)
7. Remove the intake air duct clamps.
8. Remove the intake air duct.
YAA1F750
9. Remove the fuel return and supply line.
Notice:For removal, cover around parts with cloths not
to be stained by fuel. In case of checking the injector
only, do not remove the fuel return and supply line.
Installation Notice
Tightening Torque
23 NSm (17 Ib-ft)
10. Remove the six injector connectors.
YAA1F760
11. Remove the two left and two right bolts and one cen-
ter bolt of the fuel rail assembly from the intake man-
ifold.
Installation Notice
Tightening Torque
25 NSm (18 Ib-ft)