6-34 ENGINE GENERAL INFORMATION AND DIAGNOSIS
IGNITION ADVANCE (IGNITION TIMING ADVANCE FOR NO.1 CYLINDER, °)
Ignition timing of NO.1 cylinder is commanded by ECM. 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 sensor,
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 exhaust manifold (pre-catalyst).
OXYGEN SENSOR B1 S2 (HEATED OXYGEN SENSOR-2, V)
It indicates output voltage of HO2S-2 installed on exhaust pipe (post-catalyst). It is used to detect catalyst dete-
rioration.
DESIRED IDLE (DESIRED IDLE SPEED, rpm)
The Desired Idle Speed is an ECM internal parameter which indicates the ECM 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 (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 values 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 stoichiometrical.
BATTERY VOLTAGE (V)
This parameter indicates battery positive voltage inputted from main relay to ECM.
CANIST PURGE DUTY (EVAP CANISTER PURGE FLOW DUTY, %)
This parameter indicates valve ON (valve open) time rate within a certain set cycle of EVAP purge solenoid
valve which controls the amount of EVAP purge.
0% means that the purge valve is completely closed while 100% is a fully open valve.
CLOSED THROTTLE POSITION (ON/OFF)
This parameter will read ON when throttle valve is fully closed, or OFF when the throttle is not fully closed.
FUEL CUT (ON/OFF)
ON : Fuel being cut (output signal to injector is stopped)
OFF : Fuel not being cut
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-37
ECM VOLTAGE VALUES TABLE
For TYPE A (See NOTE)
NOTE:
Type A is other than follows.
Type B is right hand steering vehicle equipped with fasten seat belt light and immobilizer control sys-
tem.
TERMINAL NO. CIRCUIT NORMAL VOLT-
AGECONDITION
C421 Ground––
2 Ground––
3 Ground––
4 EVAP canister purge valve 10 – 14 V Ignition switch ON
5 Engine coolant temp. and barometric
pressure signal for TCM (A/T)Indication
deflection
repeated 0 V
and 10 – 14 VIgnition switch ON
6 Idle air control valve 0 – 13 V At specified idle speed after engine warmed up
7 Heater of HO2S-1 (if equipped) 10 – 14 V Ignition switch ON
8 Fuel injector NO.4 10 – 14 V Ignition switch ON
9 Fuel injector NO.1 10 – 14 V Ignition switch ON
10 Sensor ground––
11 Camshaft position sensor 0 – 0.8 V and
4 – 6 VIgnition switch ON
12 Knock sensor (if equipped) 2.1 - 2.9 V Ignition switch ON
13 Heated oxygen sensor-1 (if equipped) Refer to DTC P0130 diag. flow table
CO adjusting resistor (if equipped)––
14 Engine coolant temp. sensor 0.55 - 0.95 V Ignition switch ON
Engine coolant temp. : 80°C (176°F)
15 Intake air temp. sensor 2.0 – 2.7 V Ignition switch ON
Intake air temp. : 20°C (68°F)
16 Test switch terminal (Vehicle without
immobilizer indicator lamp)4 – 6 V Ignition switch ON
17 Electric load signal (+) 0V Ignition switch ON
Small light and rear defogger OFF
10 – 14 V Ignition switch ON
Small light and rear defogger ON
18 A/C triple pressure switch 10 – 14 V A/C not operated
19 Ignition coil #2––
20 Ignition coil #1––
21 Fuel injector NO.2 10 – 14 V Ignition switch ON
22 Power source for sensor 4.75 – 5.25 V Ignition switch ON
23 Crankshaft position sensor––
24–– –
25 Shield ground––
26 Manifold absolute pressure sensor 3.3 – 4.0 V Ignition switch ON
Barometric pressure : 100 kPa (760 mmHg)
27 Diag. Switch terminal (Vehicle without
immobilizer indicator lamp)4 – 6 V Ignition switch ON
28 Monitor output (Vehicle without immo-
bilizer indicator lamp)––
29 Blank––
30 Blank––
31 Fuel injector NO.3 10 – 14 V Ignition switch ON
6-40 ENGINE GENERAL INFORMATION AND DIAGNOSIS
For TYPE B (For applicable mode, refer to NOTE in “ECM VOLTAGE VALUES TABLE”) G02 17 Power source for back-up 10 – 14 V Anytime
TERMINAL NO. CIRCUIT NORMAL VOLT-
AGECONDITION
C421Ground––
2Ground––
3Ground––
4 EVAP canister purge valve 10 – 14 V Ignition switch ON
5–– –
6 Idle air control valve 0 – 13 V At specified idle speed after engine warmed up
7 Heater of HO2S-1 (if equipped) 10 – 14 V Ignition switch ON
8 Fuel injector NO.4 10 – 14 V Ignition switch ON
9 Fuel injector NO.1 10 – 14 V Ignition switch ON
10 Sensor ground––
11 Camshaft position sensor 0 – 0.8 V and
4 – 6 VIgnition switch ON
12 Shield ground––
13 Heated oxygen sensor-1 (if equipped) Refer to DTC P0130 diag. flow table
CO adjusting resistor (if equipped)––
14 Engine coolant temp. sensor 0.55 - 0.95 V Ignition switch ON
Engine coolant temp. : 80°C (176°F)
15 Intake air temp. sensor 2.0 – 2.7 V Ignition switch ON
Intake air temp. : 20°C (68°F)
16 Throttle position sensor 0.2 – 1.0 V Ignition switch ON
Throttle valve at idle position
2.8 – 4.8 V Ignition switch ON
Throttle valve at full open position
17 EGR valve (stepper motor coil 3)
(if equipped)10 – 14 V Ignition switch ON
18 EGR valve (stepper motor coil 1)
(if equipped)10 – 14 V Ignition switch ON
19 Ignition coil #2––
20 Ignition coil #1––
21 Fuel injector NO.2 10 – 14 V Ignition switch ON
22 Power source for sensor 4.75 – 5.25 V Ignition switch ON
23 Crankshaft position sensor––
24–– –
25 knock sensor (if equipped) 2.1 – 2.9 V Ignition switch ON
26 Manifold absolute pressure sensor 3.3 – 4.0 V Ignition switch ON
Barometric pressure : 100 kPa (760 mmHg)
27–– –
28 EGR valve (stepper motor coil 4)
(if equipped)10 – 14 V Ignition switch ON
29 EGR valve (stepper motor coil 2)
(if equipped)10 – 14 V Ignition switch ON
30 A/C triple pressure switch 10 – 14 V A/C not operated
31 Fuel injector NO.3 10 – 14 V Ignition switch ON
TERMINAL
NO.CIRCUIT NORMAL
VOLTAGECONDITION
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-53
MAP SENSOR INDIVIDUAL CHECK
1) Disconnect connector from MAP sensor (1).
2) Remove MAP sensor (1).
3) Arrange 3 new 1.5 V batteries (2) in series (check that total
voltage is 4.5 – 5.0 V) and connect its positive terminal to
“Vin” terminal 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 (When input voltage is 4.5 – 5.5 V, ambient
temp. 20 – 30°C, 68 – 86°F)
If check result is not satisfactory, replace MAP sensor (1).
4) Install MAP sensor (1) securely.
5) Connect MAP sensor (1) connector securely.
INSPECTION
ALTITUDE
(Reference)BAROMETRIC
PRESSUREOUTPUT
VOLTAGE
(ft) (m) (mmHg) (kPa) (V)
0
|
2 0000
|
610760
|
707100
|
943.3 – 4.3
2 001
|
5 000611
|
1 524Under 707
over 63494
|
853.0 – 4.1
5 001
|
8 0001 525
|
2 438Under 634
over 56785
|
762.7 – 3.7
8 001
|
10 0002 439
|
3 048Under 567
over 52676
|
702.5 – 3.3
Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
2 Check MAP Sensor and Its Circuit.
1) Connect scan tool to DLC with ignition
switch OFF.
2) Turn ignition switch ON.
3) Check intake manifold pressure.
See Fig. 1.
Is it 114 kPa or more or 43 kPa or less?Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-63
DTC P0121 THROTTLE POSITION CIRCUIT RANGE/PERFORMANCE PROB-
LEM
WIRING DIAGRAM / CIRCUIT DESCRIPTION
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF. Clear DTC with ignition switch ON, check vehicle and environmental condition for :
–Altitude (barometric pressure) : 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
–Ambient temp. : –10°C, 14°F or higher
–Intake air temp. : 70°C, 158°F or lower
–Engine coolant temp. : 70 – 110°C, 158 – 230°F
2) Warm up engine to normal operating temperature.
3) Increase vehicle speed to 30 – 40 mph, 50 – 60 km/h in 3rd gear or “D” range and hold throttle valve at that
opening position for 1 min.
4) Stop vehicle.
5) Check DTC in “DTC” mode and pending DTC in “ON BOARD TEST” or “PENDING DTC” mode.
[A] : Case of TYPE A is shown (See NOTE) [B] : Case of TYPE B is shown (See NOTE)
C42-10
C42-22
5V5V
ECM
GRY/RED
GRY/BLU
ORN
C42 (31P) C41 (24P) G02 (17P)1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18 19 20 21
22 23 24 25 26 28 27 29 30 315 6
1 2 3 4 5 6 7
11 12
9 10 11 13 12 14 15 16
16 171 2
7 8
13 14 3 4
9 10
15 17 188
19 20 21 22 23 24
C42-16 [B]C41-3 [A]
NOTE:
For TYPE A and TYPE B, refer to NOTE in “ECM VOLTAGE VALUES TABLE” for applicable model.
DTC DETECTING CONDITION POSSIBLE CAUSE
DTC will set when the following conditions are detected.
After engine warmed up.
While vehicle running at specified engine speed.
No change in intake manifold pressure (constant throttle opening)
Difference between actual throttle opening (detected from TP sensor)
and opening calculated by ECM (Obtained on the basis of engine
speed and intake manifold pressure) in larger than specified value.
✱2 driving cycle detection logic, continuous monitoringTP sensor malfunction
High resistance in the circuit
ECM malfunction
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent 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, on a level road.
6-78 ENGINE GENERAL INFORMATION AND DIAGNOSIS
5 Check Fuel Injectors and Circuit.
1) Using sound scope (1) or such, check oper-
ating 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 cou-
pler) 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.
4) If OK, then check injector resistance.
Injector Resistance : 11.3 – 13.8 ohm at
20°C (68°F)
5) Carry out steps 1) and 3) on each injector.
6) Check each injector for injected fuel volume
(1) referring to Section 6E1. See Fig. 5.
Injected Fuel Volume : 43 – 47 cc/15 sec
1.45/1.51 – 1.58/1.65 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) satisfac-
tory?Go to Step 6. Check injector circuit or
replace fuel injector(s).
6 Check EVAP Canister Purge Valve.
1) Disconnect purge hose from EVAP canister
purge valve.
2) Place finger against the end of EVAP canis-
ter purge valve.
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 sys-
tem (See Section 6E1).Go to Step 7.
7 Check Intake manifold absolute pressure sen-
sor for performance (See DTC P0105 (No.11)
Diag. Flow Table).
Is it in good condition?Go to Step 8. Repair or replace.
8 Check Engine Coolant Temp. Sensor for perfor-
mance (See Section 6E1).
Is it in good condition?Go to Step 9. Replace engine coolant
temp. sensor.
9 Check Intake Air Temp. Sensor for perfor-
mance (See Section 6E1).
Is it in good condition?Go to Step 10. Replace intake air temp.
sensor.
10 Check Throttle Position Sensor for performance
(See Step 4 of DTC P0121 Diag. Flow Table).
Is it in good condition?Go to Step 11. Replace throttle position
sensor.
11 Check PCV Valve for valve clogging (See Sec-
tion 6E1).
Is it good condition?Substitute a known-good
ECM and recheck.Replace PCV valve. Step Action Yes No
6-82 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC CONFIRMATION PROCEDURE
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. : –10°C, 14°F or higher
–Intake air temp. : 70°C, 158°F or lower
–Engine coolant temp. : – 10 – 110°C, 14 – 230°F
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
analysis” and “Freeze frame data check”.
INSPECTION
DTC DETECTING CONDITION POSSIBLE CAUSE
Engine under other than high revolution condition
Not on rough road
Engine speed changing rate (Below specified value)
Manifold absolute pressure changing rate (Below
specified value)
Throttle opening changing rate (Below specified
value)
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
NOTE:
Among different types of random misfire, if misfire occurs at cylinders 1 and 4 or cylinders 3 and 2
simultaneously, it may not possible to reconfirm DTC by using the following DTC confirmation proce-
dure. When diagnosing the trouble of DTC P0300 (Random misfire detected) of the engine which is
apparently misfiring, even if DTC P0300 cannot be reconfirmed by using the following DTC confirma-
tion procedure, proceed 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 acci-
dent 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.
CAUTION:
For iridium spark plugs, do not adjust air gap or clean.
Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” performed? Go to Step 2. Go to “ENGINE
DIAG. FLOW
TABLE”.
6-94 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC P0400 EXHAUST GAS RECIRCULATION FLOW MALFUNCTION
WIRING DIAGRAM / CIRCUIT DESCRIPTION
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
Clear DTC with ignition switch ON, check vehicle and environmental condition for :
–Altitude (barometric pressure) : 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
–Ambient temp. : –10°C, 14°F or higher
–Intake air temp. : 70°C, 122°F or lower
2) Start engine and warm it up to normal operating temperature (70 – 110°C, 158 – 230°F) and run it at idle for
5 min.
3) Increase vehicle speed to 50 – 55 mph, 80 – 88 km/h in 5th gear or in “D” range.
4) Hold throttle valve at that opening position for 2 min. or longer.
5) Increase engine speed to 4000 r/min. in 3rd gear or in “2” range.
6) Release accelerator pedal and with engine brake applied, keep vehicle coasting (fuel cut condition) till
engine speed reaches 1500 r/min.
1. EGR valve [A] : Case of TYPE A is shown (See NOTE) [B] : Case of TYPE B is shown (See NOTE)
C42 (31P) C41 (24P) G02 (17P)1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18 19 20 21
22 23 24 25 26 28 27 29 30 315 6
1 2 3 4 5 6 7
11 12
9 10 11 13 12 14 15 16
16 171 2
7 8
13 14 3 4
9 10
15 17 188
19 20 21 22 23 24
+BECM
C42-18
C42-29
C42-28 C42-17
C42-1
GRY
GRN/ORN
WHT/RED
C42-3 BRN/YEL
BLK/ORN
BLK/ORN BLK/RED1
3
1 2
4
6 5
+BECM
C41-2
C41-9
C41-17 C41-8
C42-1
GRN
GRN/ORN
WHT/RED
C42-3 BRN/YEL
BLK/ORN
BLK/ORN BLK/RED1
3
1 2
4
6 5
[A][B]
NOTE:
For TYPE A and TYPE B, refer to NOTE in “ECM VOLTAGE VALUES TABLE” for applicable model.
DTC DETECTING CONDITION POSSIBLE CAUSE
While running at specified vehicle speed after engine warm-up
During deceleration (engine speed high with closed throttle position
ON) in which fuel cut is involved, difference in intake manifold abso-
lute pressure between when EGR valve is opened at specified value
and when it is closed is larger or smaller than specified value.
✱2 driving cycle detection logic, monitoring once/1 drivingEGR valve or its circuit
EGR passage
ECM
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent 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, on a level road.