Display of fuel injection signal using oscilloscope
1. CMP sensor signal
2. Fuel injector signal
3. Fuel injection time
2V/Div.
20V/Div.1
2
10ms/Div
Waveforms at specified idle speed 3 Sensor rotor
in distributorCamshaft
position sensor
6-74 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DTC P0340 CAMSHAFT POSITION (CMP) SENSOR CIRCUIT MALFUNCTION
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE
No CMP sensor signal for 2 seconds at engine
cranking (CKP sensor signal is inputted).CMP sensor circuit open or short.
Signal rotor teeth damaged.
CMP sensor malfunction, foreign material being
attached or improper installation.
ECM (PCM) malfunction.
Reference
Connect oscilloscope between terminals C01-2 and C01-10 of ECM (PCM) connector connected to ECM (PCM)
and check CMP sensor signal.
DTC CONFIRMATION PROCEDURE
1) Clear DTC.
2) Start engine and keep it at idle for 1 min.
3) 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).
6-1-34 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
CONNECTOR “C01”
TERMINAL
NO.CIRCUITNORMAL
VOLTAGECONDITION
1Ground——
2Ground——
3Ground——
4EVAP canister purge valve10 – 14 VIgnition switch ON
Indication
deflection
5Power steering switch
deflection
repeated
0 V and
Ignition switch ON
0 V and
10 – 14 V
6Idle air control valve0 – 13 VAt specified idle speed after engine warmed
up
7Heater of HO2S-110 – 14 VIgnition switch ON
8Fuel injector NO.410 – 14 VIgnition switch ON
9Fuel injector NO.110 – 14 VIgnition switch ON
10Sensor ground——
11Camshaft position sensor0 – 0.8 V
and 4 – 6 VIgnition switch ON
12Blank——
13Heater oxygen sensor-1Refer to DTC P0130 diag. flow table
14Engine coolant temp. sensor0.55 – 0.95 VIgnition switch ON
Engine coolant temp.: 80C (176F)
15Intake air temp. sensor2.0 – 2.7 VIgnition switch ON
Intake air temp.: 20C (68F)
16Blank——
17Electric load signal (+)
0 – 1 VIgnition switch ON
Small light and rear defogger OFF
17Electric load signal (+)
10 – 14 VIgnition switch ON
Small light and rear defogger ON
18Blank——
19Ignition coil #2——
20Ignition coil #1——
21Fuel injector NO.210 – 14 VIgnition switch ON
22Power source for sensor4.75 – 5.25 VIgnition switch ON
23Crankshaft position sensor (+)——
24Crankshaft position sensor (–)——
25Blank——
26Manifold absolute pressure
sensor3.3 – 4.0 VIgnition switch ON
Barometric pressure: 100 kPa (760 mmHg)
27Blank——
28Immobilizer indicator lamp0 – 2 VIgnition switch ON28Immobilizer indicator lamp10 – 14 VWhen engine running
29Blank——
30Blank——
31Fuel injector NO.310 – 14 VIgnition switch ON
6-1-36 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
CONNECTOR “C03”
TERMINAL
NO.CIRCUITNORMAL
VOLTAGECONDITION
1Malfunction indicator lamp0 – 1 VIgnition switch ON1Malfunction indicator lamp10 – 14 VWhen engine running
2
Vehicle speed sensor (M / T)
Indicator
deflection
repeated
0 V and
4 – 6 V
Ignition switch ON
Front left tire turned slowly with front right
tire locked
Output shaft speed sensor
(+) (A / T)0.4 – 0.8 VIgnition switch ON
3Blank——
4Shift solenoidA(A / T)0 VIgnition switch ON, Select lever at P-range4Shift solenoid – A (A / T)10 – 14 VIgnition switch ON, Select lever at D-range
5Throttleposition sensor
0.2 – 1.0 VIgnition switch ON
Throttle valve at idle position
5Throttle position sensor
2.8 – 4.8 VIgnition switch ON
Throttle valve at full open position
6Ignition switch10 – 14 VIgnition switch ON
7Data link connector—Ignition switch ON
8Output shaft speed sensor
(–) (A / T)0.4 – 0.8 VIgnition switch ON
9Blank——
10Sensor ground——
11Shift solenoidB(A / T)0 VIgnition switch ON, Select lever at P-range11Shift solenoid – B (A / T)10 – 14 VIgnition switch ON, Select lever at D-range
12Blank——
13Blank——
14Blank——
15Blank——
16Tachometer (if equipped)0 – 1 VIgnition switch ON
17Engine start switch6 – 12 VWhile engine cranking17g
(Engine start signal)0 – 1 VOther than above
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-69
Ignition coil assembly
for No.1 & No.4 spark plugs
Ignition coil assembly
for No.2 & No.3 spark plugs
Ignition switch
Main relay
Main
fuseRelay box
To ignition switch
CKP sensorCMP sensorNo.1 injector
No.2 injector
No.3 injector
No.4 injector Fuse box
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
DTC P0304 CYLINDER 4 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.
Below
specified value
6-1-70 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
1. CKP sensor signal
2. No.1 fuel injector signal
3. No.3 fuel injector signal
4. Fuel injection time
Display of fuel injection signal using oscilloscope
Waveforms at specified idle speed5ms/Div
DTC DETECTING CONDITIONPOSSIBLE 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
EGR system malfunction
DTC CONFIRMATION PROCEDURE
NOTE:
Among different types of random misfire, if misfire occurs at cylinders 1 and 4 or cylinders 3 and 2 simulta-
neously, it may not possible to reconfirm DTC by using the following DTC confirmation procedure. When
diagnosing the trouble of DTC P0300 (Random misfire detected) of the engine which is apparently misfir-
ing, even if DTC P0300 cannot be reconfirmed by using the following DTC confirmation procedure, pro-
ceed to the following Diag. Flow Table.
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)
–Intake air temp.: between –10C and 80C (14F and 176F)
–Engine coolant temp.: –10C, 14F or higher
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”.
Reference
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-73
Crankshaft
timing belt
pulleyCKP
sensor
Oscilloscope Waveforms
Waveforms at engine cranking (260 r/min) Waveforms at specified idle speed16 waives
for 10 signals13 waives for
10 signals
30 signal 30 signal 0.5 V / Div.
10 ms / Div.0.5 V / Div.
5 ms / Div.
DTC P0335 CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT MALFUNCTION
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE
NO CKP sensor signal for 2 seconds at engine
cranking.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 C01-23 (+) and C01-24 (–) of ECM (PCM) connector connected to ECM
(PCM) and check CKP sensor signal.
DTC CONFIRMATION PROCEDURE
1) Clear DTC and crank engine for 2 sec.
2) Select “DTC” mode on scan tool and check DTC.