OVERALL FUNCTION CHECK
Use this procedure to check the overall function of the vehicle
speed sensor circuit. During this check, a DTC might not be con-
®rmed.
1) Jack up drive wheels.
2) Start engine.
3) Read vehicle speed sensor signal in ``DATA MONITOR''
mode with CONSULT.
The vehicle speed on CONSULT should be able to
exceed 10 km/h (6 MPH) when rotating wheels with suit-
able gear position.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------OR-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1) Jack up drive wheels.
2) Start engine.
3) Rotate drive wheel by hand.
4) Check voltage between ECM terminal
V26and ground
with tester.
Voltage should vary between 0V - battery voltage.
SEF941N
SEF811R
TROUBLE DIAGNOSIS FOR ``VEHICLE SPEED SEN'' (DTC 14)
Vehicle Speed Sensor (VSS) (Cont'd)
EC-84
Electric Governor
The electric governor is built into the electronic fuel injection pump.
It moves the control sleeve to increase or decrease the amount of
fuel injected.
When current ¯ows through the coil, a magnetic force is produced,
rotating the rotor. The rotor shaft is installed to the control sleeve
via a ball pin which is eccentrically situated in relation to the rotor
shaft. With this arrangement, the control sleeve can be moved in
relation to rotor rotation.
The rotor's rotating angle is determined by a balanced condition of
magnetic force (generated by current ¯ow regulated by means of
the ECM) and tension of return spring (installed to rotor). The larger
the current ¯ow through the coil, the greater the rotor's rotating
angle. This means that the control sleeve moves to the right,
increasing the amount of fuel injected.
The ECM regulates the current ¯ow through the coil by changing
the duty ratio which controls the ON-OFF operation of the electric
governor grounding circuit.
ECM TERMINALS AND REFERENCE VALUE
Remarks: Speci®cation data are reference values and are measured between each terminal andV43(ECCS
ground) with a voltmeter.
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse
Signal)
4 B/Y ECCS relay (Self-shutoff)Ignition switch ``ON''
Ignition switch ``OFF''
For a few seconds after turning ignition switch
``OFF''0 - 1.5V
Ignition switch ``OFF''
A few seconds passed after turning ignition
switch ``OFF''BATTERY VOLTAGE
(11 - 14V)
101
107R/B Electric governorEngine is running.
Idle speedBATTERY VOLTAGE
(11 - 14V)
SEF632S
SEF633S
TROUBLE DIAGNOSIS FOR ``F/INJ F/B 2'' (DTC 18),
``F/INJ F/B'' (DTC 22), ``ELECTRIC GOV'' (DTC 25)
EC-96
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse
Signal)
102
108G/Y Electric governor groundEngine is running.
Idle speedApproximately 10V
SEF727V
Engine is running.
Engine speed is 2,000 rpm.Approximately 10V
SEF728V
11 6
11 7W Power supply for ECM Ignition switch ``ON''BATTERY VOLTAGE
(11 - 14V)
ON BOARD DIAGNOSIS LOGIC
Diagnostic
Trouble Code
No.Malfunction is detected when ....Check Items
(Possible cause)
18, 22, 25+Fuel injection feedback system does not operate prop-
erly. (This system consists essentially of ECM, electric
governor and control sleeve position sensor.)+Main power supply circuit (ECM terminals
11 6,11 7)
and fuse
+Harness or connectors
(Electric governor and control sleeve position sensor
circuit)
+Electric governor
+Electronic fuel injection pump
+ECM
TROUBLE DIAGNOSIS FOR ``F/INJ F/B 2'' (DTC 18),
``F/INJ F/B'' (DTC 22), ``ELECTRIC GOV'' (DTC 25)
Electric Governor (Cont'd)
EC-97
Injection Timing Control Valve
The injection timing control valve is built into the electronic fuel
injection pump. It controls the timer piston to change the fuel injec-
tion timing.
The timing control valve is a solenoid valve located in the line
between high-pressure chamber and low-pressure chamber. It
changes fuel pressure in the high-pressure chamber.
When current ¯ows through the solenoid (the solenoid turns ON),
the timing control valve opens, advancing fuel injection timing.
When current does not ¯ow through it, the timing control valve
closes, retarding injection timing.
The ECM emits an ON-OFF duty signal. The longer the OFF-
duration, the greater the advance angle. The longer the
ON-duration, the greater the retard angle. This means that chang-
ing the ON-OFF duty ratio makes it possible to achieve an optimal
advance angle and accurately control fuel injection timing.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Speci®cation data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
ACT INJ TIMG+Engine: After warming up
+Air conditioner switch: ``OFF''
+Shift lever: ``N''
+No-loadIdle þ9.5 to þ12.0É
2,000 rpm þ10.0 to þ15.5É
INJ TIMG C/V+Engine: After warming up, idle the engine. Approx. 50%
ECM TERMINALS AND REFERENCE VALUE
Remarks: Speci®cation data are reference values and are measured between each terminal andV43(ECCS
ground) with a voltmeter.
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse
Signal)
104
11 0L/WInjection timing control
valveEngine is running.
(Warm-up condition)
Idle speedBATTERY VOLTAGE
(11 - 14V)
SEF729V
Engine is running.(Warm-up condition)
Engine speed is 2,000 rpm.BATTERY VOLTAGE
(11 - 14V)
SEF730V
SEF638S
TROUBLE DIAGNOSIS FOR ``F/INJ TIMG F/B'' (DTC 21)
EC-101
DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK FOR AIR IN FUEL FILTER.
1. Move priming pump up and down to
purge air from fuel ®lter.
2. Perform ``DIAGNOSTIC TROUBLE
CODE CONFIRMATION PROCE-
DURE''.
NG
cOK
INSPECTION END
CHECK POWER SUPPLY.
1. Turn ignition switch ``OFF''.
2. Disconnect injection timing control valve
harness connector.
3. Turn ignition switch ``ON''.
4. Check harness continuity between ter-
minal
V2and ground with CONSULT or
tester.
Voltage: Battery voltage
OK
cNG
Check the following.
+Harness connectors
M51,F6
+Electronic fuel injection
pump harness connector
F3
+10A fuse
+Harness for open or
short between injection
timing control valve and
fuse
If NG, repair harness or
connectors.
CHECK OUTPUT SIGNAL CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Disconnect ECM harness connector.
3. Check harness continuity between ter-
minal
V1and ECM terminals104,
11 0.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Check the following.
+Electronic fuel injection
pump harness connector
F3
+Harness for open or
short between injection
timing control valve and
ECM
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
CHECK COMPONENT
(Injection timing control valve).
Refer to ``COMPONENT INSPECTION''
on next page.
OK
cNG
Replace injection timing
control valve.
Disconnect and reconnect harness connec-
tors in the circuit. Then retest.
Trouble is not ®xed.
Check ECM pin terminals for damage and
check the connection of ECM harness con-
nector. Reconnect ECM harness connector
and retest.
INSPECTION END
SEF670V
SEF685V
SEF754V
SEF755V
.
.
.
.
.
.
.
TROUBLE DIAGNOSIS FOR ``F/INJ TIMG F/B'' (DTC 21)
Injection Timing Control Valve (Cont'd)
EC-104
Accelerator Switch (F/C)
The accelerator switch is installed to the accelerator pedal assem-
bly. The switch senses accelerator position and sends an ON-OFF
signal to the ECM. The ECM uses the signal to control the fuel cut
operation at deceleration for better fuel efficiency.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Speci®cation data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
ACCEL SW (FC)+Ignition switch: ON
(Engine stopped)Accelerator pedal: released CLOSE
Accelerator pedal: slightly open OPEN
DECELER F/CUT+Engine: After warming upIdle OFF
When accelerator pedal is
released quickly with engine
speed at 3,000 rpm or more.ON
ECM TERMINALS AND REFERENCE VALUE
Remarks: Speci®cation data are reference values and are measured between each terminal andV43(ECCS
ground) with a voltmeter.
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse
Signal)
29 R/L Accelerator switch (F/C)Ignition switch ``ON''
Accelerator pedal fully releasedBATTERY VOLTAGE
(11 - 14V)
Ignition switch ``ON''
Accelerator pedal depressedApproximately 0V
ON BOARD DIAGNOSIS LOGIC
Diagnostic
Trouble Code
No.Malfunction is detected when ....Check Items
(Possible cause)
23+The OFF signal (short) is sent to the ECM for a cer-
tain period of time even when the accelerator pedal is
not being depressed.+Harness or connectors
(The switch circuit is shorted.)
+Accelerator switch (F/C)
SEF687V
TROUBLE DIAGNOSIS FOR ``ACCEL POS SW (F/C)'' (DTC 23)
EC-106
DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK OVERALL FUNCTION.1. Turn ignition switch ``ON''.
2. Check ``ACCEL SW (F/C)'' in
``DATA MONITOR'' mode with
CONSULT.
Accelerator pedal released:
OFF
Accelerator pedal depressed:
ON
--------------------------------------------------------------------------------------------------------------------------------------OR--------------------------------------------------------------------------------------------------------------------------------------
1. Turn ignition switch ``ON''.
2. Check voltage between ECM
terminal
V29and ground.
Voltage:
Accelerator pedal released
Battery voltage
Accelerator pedal depressed
Approximately 0V
NG
cOK
INSPECTION END
CHECK GROUND CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Loosen and retighten engine ground
screws.
3. Disconnect accelerator switch (F/C) har-
ness connector.
4. Check harness continuity between termi-
nal
V3and engine ground.
Continuity should exist.
If OK, check harness for short to ground
and short to power.
OK
cNG
Check the following.
+Harness connectors
M51,F6(RHD mod-
els)
+Joint connector
F18+Harness for open or
short between accelera-
tor switch (F/C) and
engine ground
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
CHECK INPUT SIGNAL CIRCUIT.
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM
terminal
V29and terminalV1.
Continuity should exist.
If OK, check harness for short to ground
and short to power.
OK
cNG
Check the following.
+Harness connectors
F6,M51(RHD mod-
els)
+Harness for open or short
between ECM and accel-
erator switch (F/C)
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
CHECK COMPONENT
[Accelerator switch (F/C)].
Refer to ``COMPONENT INSPECTION''
on next page.
OK
cNG
Replace accelerator pedal
assembly.
Disconnect and reconnect harness connec-
tors in the circuit. Then retest.
Trouble is not ®xed.
Check ECM pin terminals for damage and
check the connection of ECM harness con-
nector. Reconnect ECM harness connector
and retest.
INSPECTION END
SEF688V
SEF589S
SEF590S
SEF591S
SEF592S
.
.
.
.
.
.
.
TROUBLE DIAGNOSIS FOR ``ACCEL POS SW (F/C)'' (DTC 23)
Accelerator Switch (F/C) (Cont'd)
EC-109
Cooling Fan (Overheat)
SYSTEM DESCRIPTION
Vehicle speed sensorcVehicle speed
ECM
(ECCS-D
control
mod-
ule)
cCooling fan
relayEngine coolant temperature sensorcEngine coolant temperature
Air conditioner switch
cAir conditioner ``ON'' signal
The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, air condi-
tioner system pressure and air conditioner ON signal. The control system has 2-step control [ON/OFF].
Operation
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Speci®cation data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
AIR COND SIG+Engine: After warming up, idle
the engineAir conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor operates.)ON
COOLING FAN+When cooling fan is stopped. OFF
+When cooling fan operates. ON
ECM TERMINALS AND REFERENCE VALUE
Remarks: Speci®cation data are reference values and are measured between each terminal andV43(ECCS
ground) with a voltmeter.
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse
Signal)
14 L Cooling fan relayEngine is running.
Cooling fan is not operating.BATTERY VOLTAGE
(11 - 14V)
Engine is running.
Cooling fan is operating.0-1V
SEF757V
TROUBLE DIAGNOSIS FOR ``OVER HEAT'' (DTC 28)
EC-113