6-92 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
Fig. 1 for Step 1
DTC P1450 BAROMETRIC PRESSURE SENSOR LOW / HIGH INPUT
DTC P1451 BAROMETRIC PRESSURE SENSOR PERFORMANCE PROBLEM
WIRING DIAGRAM / CIRCUIT DESCRIPTION
Barometric pressure sensor is installed in ECM (PCM).
DTC DETECTING CONDITION
POSSIBLE CAUSE
DTC P1450:
Barometric pressure: 136 kPa 1025 mmHg or higher, or
33 kPa 250 mmHg or lowerECM (PCM) (barometric pressure sensor)
malfunction
DTC P1451:
Vehicle stopped.
Engine cranking.
Difference between barometric pressure and intake
manifold absolute pressure is 26 kPa, 200 mmHg or more.
2 driving cycle detection logic, monitoring once / 1 driving.Manifold absolute pressure sensor and its
circuit malfunction
ECM (PCM) (barometric pressure sensor)
malfunction
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) Turn ignition switch ON for 2 sec., crank engine for 2 sec. and run it at idle for 1 min.
4) Check pending DTC in “ON BOARD TEST” or “PENDING DTC” mode and DTC in “DTC” mode.
INSPECTION
DTC P1450:
Substitute a known-good ECM (PCM) and recheck.
DTC P1451:
NOTE:
Note that atmospheric pressure varies depending on weather conditions as well as altitude.
Take that into consideration when performing these check.
STEP
ACTIONYESNO
11) Connect scan tool to DLC with ignition switch
OFF.
2) Turn ignition switch ON and select “DATA
LIST” mode on scan tool.
3) Check manifold absolute pressure. See Fig. 1.
Is it barometric pressure (approx. 100 kPa,
760 mmHg) at sea level?Substitute a known-
good ECM (PCM) and
recheck.Check intake manifold
pressure sensor and its
circuit.
Go to P0105 DIAG.
FLOW TABLE.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-15
DIAGNOSTIC TROUBLE CODE (DTC) TABLE
NOTE:
1 driving cycle: MIL lights up when DTC is detected in the first driving cycle.
2 driving cycles: MIL lights up when the same DTC is detected also in the next driving cycle after DTC is
detected and stored temporarily in the first driving cycle.
DTC
NO.
DETECTING ITEMDETECTING CONDITION
(DTC will set when detecting:)MIL
P0105Manifold absolute pressure
circuit malfunction
Low pressure-high vacuum-low voltage (or MAP
sensor circuit shorted to ground)
High pressure-low vacuum-high voltage (or MAP
sensor circuit open)
1 driving
cycle
P0110Intake air temp. circuit
malfunctionIntake air temp. circuit low input
Intake air temp. circuit high input1 driving
cycle
P0115Engine coolant temp. circuit
malfunctionEngine coolant temp. circuit low input
Engine coolant temp. circuit high input1 driving
cycle
P0120Throttle position circuit
malfunctionThrottle position circuit low input
Throttle position circuit high input1 driving
cycle
P0121Throttle position circuit
performance problemPoor performance of TP sensor2 driving
cycles
P0130HO2S circuit malfunction
(Sensor-1)
Min. output voltage of HO2S-higher than
specification
Max. output voltage of HO2S-lower than
specification
2 driving
cycles
P0133HO2S circuit slow response
(Sensor-1)Response time of HO2S-1 output voltage between
rich and lean is longer than specification.2 driving
cycles
P0134HO2S circuit no activity detected
(Sensor-1)Output voltage of HO2S-1 fails to go specification.
(or HO2S-1 circuit open or short)2 driving
cycles
P0135HO2S heater circuit malfunction
(Sensor-1)Terminal voltage is lower than specification at heater
OFF or it is higher at heater ON.2 driving
cycles
P0136HO2S circuit malfunction
(Sensor-2)Max. voltage of HO2S-2 is lower than specification
or its min. voltage is higher than specification2 driving
cycles
P0141HO2S heater circuit malfunction
(Sensor-2)Terminal voltage is lower than specification at heater
OFF or it is higher at heater ON. (or heater circuit or
short)2 driving
cycles
P0171Fuel system too lean
Short term fuel trim or total fuel trim (short and long
terms added) is larger than specification for specified
time or longer. (fuel trim toward rich side is large.)2 driving
cycles
P0172Fuel system too rich
Short term fuel trim or total fuel trim (short and long
term added) is smaller than specification for
specified time or longer. (fuel trim toward lean side is
large.)
2 driving
cycles
P0300
P0301
P0302
P0303Random misfire detected
Cylinder 1 misfire detected
Cylinder 2 misfire detected
Cylinder 3 misfire detectedMisfire of such level as to cause damage to three
way catalyst
MIL
flashing
during
misfire
detection
P0304
y
Cylinder 4 misfire detectedMisfire of such level as to deteriorate emission but
not to cause damage to three way catalyst2 driving
cycles
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
6-1-18 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
FAIL-SAFE TABLE
When any of the following DTCs is detected, ECM (PCM) enters fail-safe mode as long as malfunction continues
to exist but that mode is canceled when ECM (PCM) detects normal condition after that.
DTC NO.
DETECTED ITEMFAIL-SAFE OPERATION
P0105Manifold absolute pressure circuit
malfunction
ECM (PCM) uses value determined by throttle
opening and engine speed.
ECM (PCM) stops EGR, EVAP purge and idle air
control.
P0110Intake air temp. circuit malfunctionECM (PCM) controls actuators assuming that
intake air temperature is 20C (68F).
P0115Engine coolant temp. circuit malfunctionECM (PCM) controls actuators assuming that
engine coolant temperature is 80C (176F).
P0120Throttle position circuit malfunctionECM (PCM) controls actuators assuming that
throttle opening is 20.
P0340Camshaft position sensor circuit
malfunctionECM (PCM) controls injection system sequential
injection to synchronous injection.
P0500Vehicle speed sensor malfunctionECM (PCM) stops idle air control.
P1450Barometric pressure sensor low /
high inputECM (PCM) controls actuators assuming that
barometric pressure is 100 kPa (760 mmHg).
6-1-28 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
ConditionPossible CauseReferring Item
Excessive
hydrocarbon (HC)
emission or carbon
monoxide (CO)Ignition system out of order
Faulty spark plug
Leaky or disconnected high-tension cord
Faulty ignition coil with ignitor
Low compression
Engine and emission control system out of
order
Lead contamination of three way catalytic
converter
Faulty evaporative emission control system
Fuel pressure out of specification
Closed loop system (A / F feed back
compensation) fails
–Faulty TP sensor
–Poor performance of ECT sensor or MAP
sensor
Faulty injector(s)
Faulty ECM (PCM)
Others
Engine not at normal operating temperature
Clogged air cleaner
Vacuum leaks
Spark plugs in Section 6F1
High-tension cords in Section 6F1
Ignition coil assembly in Section
6F1
Refer to “Low compression”
section
Check for absence of filler neck
restrictor
EVAP control system in Section
6E2
Diagnostic Flow Table B-3
TP sensor in Section 6E2
ECT sensor or MAP sensor in
Section 6E2
Diagnostic Flow Table B-1
Excessive nitrogen
oxides (NOx)
emissionIgnition system out of order
Improper ignition timing
Engine and emission control system out of
order
Lead contamination of catalytic converter
Faulty EGR system
Fuel pressure out of specification
Closed loop system (A / F feed back
compensation) fails
–Faulty TP sensor
–Poor performance of ECT sensor or MAP
sensor
Faulty injector(s)
Faulty ECM (PCM)
See section 6F1
Check for absence of filler neck
restrictor.
EGR system in Section 6E2
Diagnostic Flow Table B-3
TP sensor in Section 6E2
ECT sensor or MAP sensor in
Section 6E2
Diagnostic Flow Table B-1
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-29
SCAN TOOL DATA
As the data values given below are standard values estimated on the basis of values obtained from the normally
operating vehicles by using a scan tool, use them as reference values. Even when the vehicle is in good condition,
there may be cases where the checked value does not fall within each specified data range. Therefore, judgment
as abnormal should not be made by checking with these data alone.
Also, conditions in the below table that can be checked by the scan tool are those detected by ECM (PCM) and
output from ECM (PCM) as commands and there may be cases where the engine or actuator is not operating (in
the condition) as indicated by the scan tool. Be sure to use the timing light to check the ignition timing.
NOTE:
With the generic scan tool, only star () marked data in the table below can be read.
When checking the data with the engine running at idle or racing, be sure to shift M / T gear to the neutral
gear position and A / T gear to the “Park” position and pull the parking brake fully. Also, if nothing or “no
load” is indicated, turn OFF A / C, all electric loads, P / S and all the other necessary switches.
SCAN TOOL DATAVEHICLE CONDITIONNORMAL CONDITION /
REFERENCE VALUES
FUEL SYSTEM B1 (FUEL
SYSTEM STATUS)At specified idle speed after warming upCLOSED
(closed loop)
CALC LOAD
(CALCULATED LOADAt specified idle speed with no load after
warming up3 – 9%(
VALUE)At 2500 r / min with no load after warming up12 – 17%
COOLANT TEMP.
(ENGINE COOLANT
TEMP.)
At specified idle speed after warming up85 – 100C,
185 – 212F
SHORT FT BI (SHORT
TERM FUEL TRIM)At specified idle speed after warming up–20 – +20%
LONG FT BI (LONG
TERM FUEL TRIM)At specified idle speed after warming up–15 – +15%
MAP (INTAKE
MANIFOLD ABSOLUTE
PRESSURE)At specified idle speed with no load after
warming up24 – 37 kPa,
180 – 280 mmHg
ENGINE SPEEDAt idling with no load after warming up
Desired
idle speed
± 50 r / min
VEHICLE SPEEDAt stop0 km / h, 0 MPH
IGNITION ADVANCE
(IGNITION TIMING
ADVANCE FOR NO.1
CYLINDER)
At specified idle speed with no load after
warming up9 – 15 BTDC
INTAKE AIR TEMP.At specified idle speed after warming upAmbient +35C (95F)
temp.–5C (23F)
MAF (MASS AIR FLOW
RATE)
At specified idle speed with no load after
warming up0 – 4 gm / sec
RATE)At 2500 r / min with no load after warming up4 – 9 gm / sec
THROTTLE POS
(ABSOLUTE
Ignition switch
ON / engineThrottle valve fully closed7 – 18%
(ABSOLUTE
THROTTLE POSITION)
ON / engine
stoppedThrottle valve fully open70 – 100%
O2S B1 S1 (HEATED
OXYGEN SENSOR-1)At specified idle speed after warming up0.05 – 0.95 V
O2S B1 S2 (HEATED
OXYGEN SENSOR-2)When engine is running at 2000 r / min. for
3 min or longer after warming up.0 – 0.95 V
O2S FT B1 S1At specified idle speed after warning up–20 – +20%
DIS. WITH MIL ON————
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