
MAP
sensor
To other sensorsTo TP sensor
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-43
DTC P0105 MANIFOLD ABSOLUTE PRESSURE (MAP) CIRCUIT
MALFUNCTION
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE
MAP: 4.9 kpa, 37 mmHg or less
(Low pressure – High vacuums – Low voltage)
MAP: 114.7 kpa, 860 mmHg or more
(High pressure – Low vacuums – High voltage)“G” circuit open
“P” circuit open or shorted to ground
“G” circuit open or shorted to ground
MAP sensor malfunction
ECM (PCM) malfunction
NOTE:
When DTC P0120 is indicated together, it is possible that “P” circuit is open.
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.

6-1-44 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
MAP Sensor Individual Check
1) Disconnect coupler from MAP sensor (1).
2) Remove MAP sensor (1).
3) Arrange 3 new 1.5 V batteries (2) in series (check that total volt-
age is 4.5 – 5.0 V) and connect its positive terminal to “Vin” termi-
nal of sensor and negative terminal to “Ground” terminal. Then
check voltage between “Vout” and “Ground”.
Also, check if voltage reduces when vacuum is applied up to 400
mmHg by using vacuum pump (3).
Output voltage (Vin voltage 4.5 – 5.5 V, ambient temp. 20 –
30C, 68 – 86F)
ALTITUDE
BAROMETRICOUTPUT
(Reference)PRESSUREVOLTAGE
(ft)(m)(mmHg)(kPa)(V)
0
0
760
100
3343
2 000
610
707
94
3.3 – 4.3
2 001
611
Under 70794
3041
5 000
1 524over 634
85
3.0 – 4.1
5 001
1 525
Under 63485
2737
8 000
2 438over 567
76
2.7 – 3.7
8 001
2 439
Under 56776
25–33
10 000
3 048over 526
70
2.5 – 3.3
If check result is not satisfactory, replace MAP sensor (1).
4) Install MAP sensor (1) securely.
5) Connect MAP sensor (1) coupler securely.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-65
Ignition
switch
Main
fuseMain relay
To ignition
switchTo other sensor Relay boxNo.1 injector
No.2 injector
No.3 injector
No.4 injector Fuse box
Signal to decrease amount of fuel injection
Signal to increase amount of fuel injection
High voltage
Low voltage
A / F mixture
becomes
richerOxygen
concentration
decreases
A / F mixture Oxygen
Fuel injectorSensed
information
A / F mixture
Exhaust gas
becomes
leanerconcentration
increases
DTC P0171 FUEL SYSTEM TOO LEAN
DTC P0172 FUEL SYSTEM TOO RICH
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE
When following condition occurs while engine running under
closed loop condition.
–Air / fuel ratio too lean
Total fuel trim (short and long terms added) is
more than 30%
or
–Air / fuel ratio too rich
(Total fuel trim is less than –30%)
2 driving cycle detection logic, continuous monitoring.Vacuum leaks (air drawn in).
Exhaust gas leakage.
Heated oxygen sensor-1 circuit
malfunction.
Fuel pressure out of specification.
Fuel injector malfunction (clogged or
leakage).
MAP sensor poor performance.
ECT sensor poor performance.
IAT sensor poor performance.
TP sensor poor performance.
EVAP control system malfunction.
PCV valve malfunction.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-67
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE
DIAG. FLOW
TABLE”.
2Is there DTC(s) other than fuel system
(DTC P0171 / P0172)?Go to applicable
DTC Diag. Flow
Table.Go to Step 3.
3Check HO2S-1 Output Voltage.
1) Connect scan tool to DLC with ignition switch OFF.
2) Warm up engine to normal operating temperature and keep
it at 2000 r / min. for 60 sec.
3) Repeat racing engine (Repeat depressing accelerator pedal
5 to 6 times continuously and take foot off from pedal to
enrich and enlean A / F mixture). See Fig. 1.
Does HO2S-1 output voltage deflect between below 0.3 V and
over 0.6 V repeatedly?Go to Step 4.Go to DTC
P0130 Diag.
Flow Table
(HO2S-1 circuit
check).
4Check Fuel Pressure (Refer to section 6E2 for details).
1) Release fuel pressure from fuel feed line.
2) Install fuel pressure gauge.
3) Check fuel pressure. See Fig. 2.
With fuel pump operating
and engine at stop : 270 – 310 kPa, 2.7 – 3.1 kg / cm
2,
38.4 – 44.0 psi.
At specified idle speed : 200 – 240 kPa, 2.0 – 2.4 kg / cm
2,
28.4 – 34.1 psi.
Is measured value as specified?
Go to Step 5.Go to Diag. Flow
Table B-3 Fuel
Pressure Check.
5Check Fuel Injectors and Circuit.
1) Using sound scope (1) or such, check operating sound of
each injector (2) when engine is running. Cycle of operating
sound should vary according to engine speed. See Fig. 3.
If no sound or an unusual sound is heard, check injector
circuit (wire or coupler) or injector.
2) Turn ignition switch OFF and disconnect a fuel injector
connector.
3) Check for proper connection to fuel injector at each terminal.
See Fig. 4.Go to Step 6.Check injector
circuit or replace
fuel injector(s).
4) If OK, then check injector resistance.
Injector Resistance: 12 – 13 ohm at 20C (68F)
5) Carry out steps 1) and 3) on each injector.
6) Check each injector for injected fuel volume referring to
Section 6E2. See Fig. 5.
Injected Fuel Volume: 38 – 48 cc / 15 sec 1.28 /
1.34 – 1.62 / 1.69 US / Imp.oz / 15 sec)
7) Check each injector for fuel leakage after injector closed.
Fuel Leakage: Less than 1 drop / min.
Is check result in step 1) and 3) to 7) satisfactory?
6Check EVAP Canister Purge Valve.
1) Disconnect purge hose (1) from EVAP canister.
2) Place finger against the end of disconnected hose.
3) Check that vacuum is not felt there when engine is cool and
running at idle. See Fig. 6.
Is vacuum felt?Check EVAP
control system
(See Section
6E2).Go to Step 7.
7Check intake manifold absolute pressure sensor for
performance (See DTC P0105 Diag. Flow Table).
Is it in good condition?Go to Step 8.Repair or
replace.

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

6-1-72 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
Disconnect connectors when checking plugs
for spark1. Fuel delivery pipe
2. Fuel feed hose
3. FUel pressure
gauge & 3 way joint
STEPACTIONYESNO
6Check PCV valve for clogging (See Section 6E2).
Is it in good condition?Go to Step 7.Replace PCV valve.
7Check EVAP Canister Purge Valve for Closing.
1) Disconnect purge hose (1) from EVAP canister.
2) Place finger against the end of disconnected hose.
3) Check that vacuum is not felt there, when engine is
cool and running at idle. See Fig. 7.
Is vacuum felt?Check EVAP
control system
(See Section 6E2).Go to Step 8.
8Check intake manifold pressure sensor for performance
(See DTC P0105 Diag. Flow Table).
Is it in good condition?Go to Step 9.Repair or replace.
9Check engine coolant temp. sensor for performance
(See Section 6E2).
Is it in good condition?Go to Step 10.Replace engine
coolant temp.
sensor.
10Check parts or system which can cause engine rough
idle or poor performance.
–Engine compression (See Section 6A1).
–Valve lash (See Section 6A1).
–Valve timing (Timing belt installation. See Section 6A1).
Are they in good condition?Check wire harness
and connection of
ECM (PCM) ground,
ignition system and
fuel injector for
intermittent open
and short.Repair or replace.
Fig. 1 for Step 3 Fig. 2 for Step 3 Fig. 3 for Step 4
Fig. 4 for Step 5 Fig. 5 for Step 4 Fig. 6 for Step 5
Fig. 7 for Step 7

Applying Vacuum Displayed Value on Scan Tool
0Barometric pressure
(Approx. 100 kPa, 760 mmHg)
27 kPa
200 mmHgBarometric pressure –27 kPa
(Approx. 73 kPa, 560 mmHg
67 kPa
500 mmHgBarometric pressure –67 kPa
(Approx. 33 kPa, 260 mmHg)
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-95
Fig. 2 for Step 2
STEPACTIONYESNO
2Check MAP Sensor
1) Remove MAP sensor from intake manifold and connect
vacuum pump gauge to MAP sensor. See Fig. 2.
2) Connect scan tool to DLC and turn ignition switch ON.
3) Check intake manifold absolute pressure displayed on
scan tool under following conditions.
Is check result satisfactory?Check air intake
system for air
being drawn in
and engine
compression.
If OK, then
substitute a
known-good ECM
(PCM) and
recheck.Replace MAP
sensor.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-101
1. Fuel injector
2. Delivery pipe
3. Fuel regulator
4. Fuel filter
5. Fuel pump
Special Tool
(A) Gauge (09912-58441)
(B) Hose (09912-58431)
(C) 3-way joint (09912-58490)
TABLE B-3 FUEL PRESSURE CHECK
INSPECTION
STEPACTIONYESON
11) Release fuel pressure from fuel feed line.
2) Install fuel pressure gauge.
3) Check fuel pressure by repeating ignition switch
ON and OFF.
Is fuel pressure then 270 – 310 kPa
(2.7 – 3.1 kg / cm
2, 38.4 – 44.0 psi)?
Go to Step 2.Go to Step 5.
2Is 200 kPa (2.0 kg / cm2, 28.4 psi) or higher fuel
pressure retained for 1 minute after fuel pump is
stopped at step 1?Go to Step 3.Go to Step 4.
31) Start engine and warm it up to normal operating
temperature.
2) Keep it running at specified idle speed.
Is fuel pressure then within 200 – 240 kPa
(2.0 – 2.4 kg / cm
2, 28.4 – 34.1 psi)?
Normal fuel pressure.Clogged vacuum
passage for fuel
pressure regulator or
faulty fuel pressure
regulator.
4Is there fuel leakage from fuel feed line hose, pipe or
their joint?Fuel leakage from
hose, pipe or joint.Go to Step 10.
5Was fuel pressure higher than spec. in step 1?Go to Step 6.Go to Step 7.
61) Disconnect fuel return hose from fuel pressure
regulator and connect new return hose to it.
2) Put the other end of new return hose into approved
gasoline container.
3) Operate fuel pump.
Is specified fuel pressure obtained then?Restricted fuel return
hose or pipe.Faulty fuel pressure
regulator.