6-16 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DTC
NO.DETECTING ITEMDETECTING CONDITION
(DTC will set when detecting:)MIL
P0335Crankshaft position sensor
circuit malfunctionNo signal during engine running1 driving cycle
P0340Camshaft position sensor
circuit malfunctionNo signal for 2 sec. during engine cranking1 driving cycle
P0420Catalyst system efficiency
below threshold
Output waveforms of HO2S-1 and HO2S-2
are similar.
(Time from output voltage change of HO2S-1
to that of HO2S-2 is shorter than
specification.)
2 driving cycles
P0443EVAP Purge control valve
circuit malfunctionPurge control valve circuit is open or shorted
to ground2 driving cycles
P0480Radiator fan control circuit
malfunctionRadiator cooling fan relay terminal voltage is
low when cooling temp. is lower than
specification
2 driving cycles
P0500Vehicle speed sensor
malfunctionNo signal while running in “D” range or during
fuel cut at decelerating2 driving cycles
P0505Idle control system malfunction
Throttle opening change is small as compared
with electrically live time. Throttle valve opening
is not within its target range with CTP switch ON
or drive voltage exists though ECM (PCM) is not
outputting ISC drive command.
1 driving cycle
P0510Closed throttle position switch
malfunctionSwitch does not change from ON to OFF
(or from OFF to ON) even when vehicle speed
reaches over (or below) specification.
2 driving cycle
P1250Early Fuel Evaporation Heater
Circuit MalfunctionHeater monitor terminal voltage is higher than
specified value when EFE OFF or it is lower
than specified value when EFE ON.
2 driving cycles
P1450Barometric pressure sensor
circuit malfunctionBarometric pressure is lower or higher than
specification. (or sensor malfunction)1 driving cycle
P1451Barometric pressure sensor
performance problem
Difference between manifold absolute
pressure (MAP sensor value) and
barometric pressure (barometric pressure
sensor value) is larger than specification
during cranking.
2 driving cycles
P1500Starter signal circuit
malfunctionStarter signal is not inputted from engine
cranking till its start and after or it is always
inputted
2 driving cycles
P1510ECM (PCM) backup power
source malfunctionNo backup power after starting engine1 driving cycle
6-32 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
SCAN TOOL DATA DEFINITIONS
FUEL SYSTEM (FUEL SYSTEM STATUS)
Air / fuel ratio feedback loop status displayed as either
open or closed loop. Open indicates that ECM (PCM)
ignores feedback from the exhaust oxygen sensor.
Closed indicates final injection duration is corrected
for oxygen sensor feedback.
CALC LOAD (CALCULATED LOAD VALUE, %)
Engine load displayed as a percentage of maximum
possible load. Value is calculated mathematically us-
ing the formula: actual (current) intake air volume
maximum possible intake air volume x 100%.
COOLANT TEMP.
(ENGINE COOLANT TEMPERATURE, C, F)
It is detected by engine coolant temp. sensor
SHORT FT B1 (SHORT TERM FUEL TRIM, %)
Short term fuel trim value represents short term
corrections to the air / fuel mixture computation. A val-
ue of 0 indicates no correction, a value greater than
0 means an enrichment correction, and a value less
than 0 implies an enleanment correction.
LONG FT B1 (LONG TERM FUEL TRIM, %)
Long term fuel trim Value represents long term correc-
tions to the air / fuel mixture computation. A value of 0
indicates no correction, a value greater than 0 means
an enrichment correction, and a value less than 0 im-
plies an enleanment correction.
MAP (INTAKE MANIFOLD ABSOLUTE
PRESSURE, kPa, inHg)
It is detected by manifold absolute pressure sensor and
used (among other things) to compute engine load.
ENGINE SPEED (rpm)
It is computed by reference pulses from crankshaft
position sensor.
VEHICLE SPEED (km / h, MPH)
It is computed based on pulse signals from vehicle
speed sensor.
IGNITION ADVANCE
(IGNITION TIMING ADVANCE FOR NO.1
CYLINDER, )
Ignition timing of NO.1 cylinder is commanded by
ECM (PCM). The actual ignition timing should be
checked by using the timing light.
INTAKE AIR TEMP. (C, F)
It is detected by intake air temp. sensor and used to
determine the amount of air passing into the intake
manifold as air density varies with temperature.
MAF (MASS AIR FLOW RATE, gm / s, lb / min)
It represents total mass of air entering intake manifold
which is computed based on signals from MAP sen-
sor, IAT sensor, TP sensor, etc.
THROTTLE POS
(ABSOLUTE THROTTLE POSITION, %)
When throttle position sensor is fully closed position,
throttle opening is indicated as 0% and 100% full open
position.
OXYGEN SENSOR B1 S1
(HEATED OXYGEN SENSOR-1, V)
It indicates output voltage of HO2S-1 installed on ex-
haust manifold (pre-catalyst).
OXYGEN SENSOR B1 S2
(HEATED OXYGEN SENSOR-2, V)
It indicates output voltage of HO2S-2 installed on ex-
haust pipe (post-catalyst). It is used to detect catalyst
deterioration.
DESIRED IDLE (DESIRED IDLE SPEED, rpm)
The Desired Idle Speed is an ECM (PCM) internal pa-
rameter which indicates the ECM (PCM) requested
idle. If the engine is not running, this number is not valid.
TP SENSOR VOLT (THROTTLE POSITION
SENSOR OUTPUT VOLTAGE, V)
The Throttle Position Sensor reading provides throttle
valve opening information in the form of voltage.
INJ PULSE WIDTH
(FUEL INJECTION PULSE WIDTH, msec.)
This parameter indicates time of the injector drive
(valve opening) pulse which is output from ECM
(PCM) (but injector drive time of NO.1 cylinder for
multiport fuel injection).
IAC FLOW DUTY (IDLE AIR (SPEED) CONTROL
DUTY, %)
This parameter indicates opening of the throttle valve
in terms of percentage to opening controllable by the
ISC actuator.
TOTAL FUEL TRIM (%)
The value of Total Fuel Trim is obtained by putting val-
ues of short Term Fuel Trim and Long Term Fuel Trim
together. This value indicates how much correction is
necessary to keep the air / fuel mixture stoichiomet-
rical.
BATTERY VOLTAGE (V)
This parameter indicates battery positive voltage in-
putted from main relay to ECM (PCM).
6-36 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
CONNECTOR “C01”
TER-
MINALWIRE
COLORCIRCUITSTANDARD
VOLTAGECONDITION
1LgPower source for sensor4.75 – 5.25 VIgnition switch ON
2OrCamshaft position sensor (+)——
3W/BCrankshaft position sensor
(+)——
4Gr / GClosed throttle position switch
0 – 1 V
Ignition switch ON, ISC actuator
plunger is in contact with throttle lever
screw
4Gr / G(In ISC actuator)
4 – 6 V
Ignition switch ON
Plunger is apart from throttle lever
screw
5Lg / RManifold absolute pressure
sensor3.3 – 4.0 V
Ignition switch ON
Barometric pressure: 100 kPa,
760 mmHg
6Lg / WThrottle position sensor
0.2 – 1.0 V
Ignition switch ON, when clearance
between throttle lever and throttle stop
screw is less than 0.35 mm (0.014 in.)
2.8 – 4.8 VIgnition switch ON
Throttle valve at full open position
7Gr / WEngine coolant temp. sensor0.55 – 0.95 VIgnition switch ON
Engine coolant temp.: 80C (176F)
8P/BHeater of H02S-110 – 14 VIgnition switch ON
9GGround for sensors——
10WCamshaft position sensor (–)——
11W/RCrankshaft position sensor
(+)——
12W/BEFE heater monitor0 – 1 VHeater relay OFF12W/BEFE heater monitor10 – 14 VHeater relay ON
13RHeated oxygen sensor-1Refer to DTC flow chart
14GrIntake air temp. sensor2.0 – 2.7 V
Ignition switch ON
Sensor ambient temp.
(Intake air temp): 20C (68F)
10 – 14 VIgnition switch ON
15Bl / WPower steering pressure
switch (If equipped)
0 – 1 V
With engine running at idle speed,
turning steering wheel to the right or left
as far as it stops, repeating it a few
times
16B/YEngine start switch6 – 12 VWhile engine cranking16B/Yg
(Engine start signal)0 – 1 VOther than above
Ignition coil
Igniter
Ignition switch
Main
fuse
Injector resistor
Fuel injector
Crankshaft
position sensor
Camshaft
position sensor
Ground
at engine “I / G COIL METER”
Main relay
6-68 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DTC P0300 RANDOM MISFIRE DETECTED (Misfire detected at 2 or more
cylinders)
DTC P0301 CYLINDER 1 MISFIRE DETECTED
DTC P0302 CYLINDER 2 MISFIRE DETECTED
DTC P0303 CYLINDER 3 MISFIRE DETECTED
CIRCUIT DESCRIPTION
ECM (PCM) monitors crankshaft revolution speed and engine speed via the crankshaft position sensor and cylin-
der No. via the camshaft position sensor. Then it calculates the change in the crankshaft revolution speed and from
how many times such change occurred in every 200 or 1000 engine revolutions, it detects occurrence of misfire.
When ECM (PCM) detects a misfire (misfire rate per 200 revolutions) which can cause overheat and damage to
the three way catalytic converter, it makes the malfunction indicator lamp (MIL) flash as long as misfire occurs at
that rate.
After that, however, when the misfire rate drops, MIL remains ON until it has been judged as normal 3 times under
the same driving conditions.
Also, when ECM (PCM) detects a misfire (misfire rate per 1000 revolutions) which will not cause damage to three
way catalytic converter but can cause exhaust emission to be deteriorated, it makes MIL light according to the 2
driving cycle detection logic.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-69
Below
specified value DTC DETECTING CONDITION
POSSIBLE CAUSE
Engine under other than high revolution condition
Not on rough road
Engine speed changing rate
Manifold absolute
pressure changing rate
Throttle opening changing rate
Misfire rate per 200 or 1000 engine revolutions (how
much and how often crankshaft revolution speed
changes) is higher than specified valueEngine overheating
Vacuum leaks (air inhaling) from air intake system
Ignition system malfunction (spark plug(s), high-
tension cord(s), ignition coil assembly)
Fuel pressure out of specification
Fuel injector malfunction (clogged or leakage)
Engine compression out of specification
Valve lash (clearance) out of specification
Manifold absolute pressure sensor malfunction
Engine coolant temp. sensor malfunction
PCV valve malfunction
EVAP control system malfunction
DTC CONFIRMATION PROCEDURE
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic accident
and be very careful during testing to avoid occurrence of an accident.
Road test should be carried out with 2 persons, a driver and a tester.
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) Check vehicle and environmental condition for:
–Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
–Ambient temp.: –10C, 14F or higher
–Intake air temp.: 70C, 158F or lower
–Engine coolant temp.: –10 – 11 0C, 14 – 230F
4) Start engine and keep it at idle for 2 min. or more.
5) Check DTC in “DTC” mode and pending DTC in “ON BOARD TEST” or “PENDING DTC” mode.
6) If DTC is not detected at idle, consult usual driving based on information obtained in “Customer complaint analy-
sis” and “Freeze frame data check”.
Oscilloscope Waveforms
Crankshaft
timing belt pulleyCKP
sensor
2V/Div.
5ms/Div.
Waveforms at specified idle speed
6-72 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DTC P0335 CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT MALFUNCTION
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE
No CKP sensor signal during 1 revolution of
camshaft.CKP sensor circuit open or short.
Crankshaft timing belt pulley teeth damaged.
CKP sensor malfunction, foreign material being
attached or improper installation.
ECM (PCM) malfunction.
Reference
Connect oscilloscope between terminals C01-3 (+) and C01-11 (–) of ECM (PCM) connector connected to ECM
(PCM) and check CKP sensor signal.
DTC CONFIRMATION PROCEDURE
1) Clear DTC, start engine and keep it at idle for 1 min.
2) Select “DTC” mode on scan tool and check DTC.
6-1-16 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
DTC
NO.DETECTING ITEMDETECTING CONDITION
(DTC will set when detecting:)MIL
P0335Crankshaft position sensor
circuit malfunctionNo signal for 2 sec. During engine cranking1 driving
cycle
P0340Camshaft position sensor circuit
malfunctionNo signal during engine running1 driving
cycle
P0400Exhaust gas recirculation
flow malfunction detectedExcessive or insufficient EGR flow2 driving
cycles
P0420Catalyst system efficiency below
threshold
Output waveforms of HO2S-1 and HO2S-2 are
similar.
(Time from output voltage change of HO2S-1 to that
of HO2S-2 is shorter than specification.)
2 driving
cycles
P0443Purge control valve circuit
malfunctionPurge control valve circuit is open or shorted to
ground2 driving
cycles
P0480Radiator fan control circuit
malfunctionRadiator cooling fan relay terminal voltage is low
when cooling temp. is lower than specification2 driving
cycles
P0500Vehicle speed sensor
malfunctionNo signal while running in “D” range or during fuel cut
at decelerating2 driving
cycles
P0505Idle control system malfunctionNo closed signal to IAC valve is detected2 driving
cycles
P0601Internal control module memory
check sum errorData write error (or check sum error) when written
into ECM (PCM)1 driving
cycle
P1450Barometric pressure sensor
circuit malfunctionBarometric pressure is lower or higher than
specification. (or sensor malfunction)1 driving
cycle
P1451Barometric pressure sensor
performance problem
Difference between manifold absolute pressure
(MAP sensor value) and barometric pressure
(barometric pressure sensor value) is larger than
specification during cranking.
2 driving
cycles
P1500Starter signal circuit malfunctionStarter signal is not inputted from engine cranking till
its start and after or it is always inputted2 driving
cycles
P1510ECM (PCM) backup power
source malfunctionNo backup power after starting engine1 driving
cycle
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-31
SCAN TOOL DATA DEFINITIONS
FUEL SYSTEM (FUEL SYSTEM STATUS)
Air / fuel ratio feedback loop status displayed as either
open or closed loop. Open indicates that ECM (PCM)
ignores feedback from the exhaust oxygen sensor.
Closed indicates final injection duration is corrected
for oxygen sensor feedback.
CALC LOAD (CALCULATED LOAD VALUE, %)
Engine load displayed as a percentage of maximum
possible load. Value is calculated mathematically us-
ing the formula: actual (current) intake air volume
maximum possible intake air volume x 100%.
COOLANT TEMP.
(ENGINE COOLANT TEMPERATURE, C, F)
It is detected by engine coolant temp. sensor
SHORT FT B1 (SHORT TERM FUEL TRIM, %)
Short term fuel trim value represents short term
corrections to the air / fuel mixture computation. A val-
ue of 0 indicates no correction, a value greater than
0 means an enrichment correction, and a value less
than 0 implies an enleanment correction.
LONG FT B1 (LONG TERM FUEL TRIM, %)
Long term fuel trim Value represents long term correc-
tions to the air / fuel mixture computation. A value of 0
indicates no correction, a value greater than 0 means
an enrichment correction, and a value less than 0 im-
plies an enleanment correction.
MAP (INTAKE MANIFOLD ABSOLUTE
PRESSURE, kPa, inHg)
It is detected by manifold absolute pressure sensor and
used (among other things) to compute engine load.
ENGINE SPEED (rpm)
It is computed by reference pulses from crankshaft
position sensor.
VEHICLE SPEED (km / h, MPH)
It is computed based on pulse signals from vehicle
speed sensor.
IGNITION ADVANCE
(IGNITION TIMING ADVANCE FOR NO.1
CYLINDER, )
Ignition timing of NO.1 cylinder is commanded by
ECM (PCM). The actual ignition timing should be
checked by using the timing light.
INTAKE AIR TEMP. (C, F)
It is detected by intake air temp. sensor and used to
determine the amount of air passing into the intake
manifold as air density varies with temperature.
MAF (MASS AIR FLOW RATE, gm / s, lb / min)
It represents total mass of air entering intake manifold
which is computed based on signals from MAP sen-
sor, IAT sensor, TP sensor, etc.
THROTTLE POS
(ABSOLUTE THROTTLE POSITION, %)
When throttle position sensor is fully closed position,
throttle opening is indicated as 0% and 100% full open
position.
OXYGEN SENSOR B1 S1
(HEATED OXYGEN SENSOR-1, V)
It indicates output voltage of HO2S-1 installed on ex-
haust manifold (pre-catalyst).
OXYGEN SENSOR B1 S2
(HEATED OXYGEN SENSOR-2, V)
It indicates output voltage of HO2S-2 installed on ex-
haust pipe (post-catalyst). It is used to detect catalyst
deterioration.
DESIRED IDLE (DESIRED IDLE SPEED, rpm)
The Desired Idle Speed is an ECM (PCM) internal pa-
rameter which indicates the ECM (PCM) requested
idle. If the engine is not running, this number is not valid.
TP SENSOR VOLT (THROTTLE POSITION
SENSOR OUTPUT VOLTAGE, V)
The Throttle Position Sensor reading provides throttle
valve opening information in the form of voltage.
INJ PULSE WIDTH
(FUEL INJECTION PULSE WIDTH, msec.)
This parameter indicates time of the injector drive
(valve opening) pulse which is output from ECM
(PCM) (but injector drive time of NO.1 cylinder for
multiport fuel injection).
IAC FLOW DUTY (IDLE AIR (SPEED) CONTROL
DUTY, %)
This parameter indicates current flow time rate within
a certain set cycle of IAC valve (valve opening rate)
which controls the amount of bypass air (idle speed).
TOTAL FUEL TRIM (%)
The value of Total Fuel Trim is obtained by putting val-
ues of short Term Fuel Trim and Long Term Fuel Trim
together. This value indicates how much correction is
necessary to keep the air / fuel mixture stoichiomet-
rical.
BATTERY VOLTAGE (V)
This parameter indicates battery positive voltage in-
putted from main relay to ECM (PCM).