6-32 ENGINE GENERAL INFORMATION AND DIAGNOSIS
✱THROTTLE POS
(ABSOLUTE THROTTLE
POSITION)Ignition switch
ON/engine
stoppedThrottle valve fully closed 7 – 18%
Throttle valve fully open 70 – 90%
✱O2S B1 S1
(HEATED OXYGEN SEN-
SOR-1)At specified idle speed after warming up 0.01 – 0.95 V
∆✱O2S B1 S2
(HEATED OXYGEN SEN-
SOR-2)When engine is running at 2000 r/min. for 3
min or longer after warming up.0.01 – 0.95 V
∆✱O2S FT B1 S1 At specified idle speed after warning up– 20 – +20%
∆✱DIS. WITH MIL ON––
DESIRED IDLE
(DESIRED IDLE SPEED)At idling with no load after warming up, M/T
at neutral, A/T at “P” rangeM/T 700 r/min
A/T 750 r/min
TP SENSOR VOLT
(THROTTLE POSITION
SENSOR OUTPUT VOLT-
AGE)Ignition switch
ON/engine
stoppedThrottle valve fully closed More than 0.2 V
Throttle valve fully open Less than 4.8 V
INJ PULSE WIDTH
(FUEL INJECTION PULSE
WIDTH)At specified idle speed with no load after
warming up2.0 – 3.6 msec.
At 2500 r/min with no load after warming up 2.0 – 3.6 msec.
IAC FLOW DUTY
(IDLE AIR CONTROL
FLOW DUTY)At idling with no load after warming up 5 – 25%
TOTAL FUEL TRIM At specified idle speed after warming up– 35 – +35%
BATTERY VOLTAGE Ignition switch ON/engine stop 12 – 14 V
CANIST PRG DUTY
(EVAP CANISTER PURGE
FLOW DUTY)–0 – 100%
CLOSED THROT POS
(CLOSED THROTTLE
POSITION)Throttle valve at idle position ON
Throttle valve opens larger than idle posi-
tionOFF
FUEL CUT When engine is at fuel cut condition ON
Other than fuel cut condition OFF
RADIATOR FAN
(RADIATOR FAN CON-
TROL RELAY)Ignition switch
ONEngine coolant temp. :
Lower than 95°C (203°F)OFF
Engine coolant temp. :
97.5°C (208°F) or higherON
ELECTRIC LOAD Ignition switch ON/Headlight, small light
and rear window defogger all turned OFFOFF
Ignition switch ON/Headlight, small light or
rear window defogger turned ONON
A/C SWITCH Engine running after warming up, A/C not
operatingOFF
Engine running after warming up, A/C oper-
atingON SCAN TOOL DATA VEHICLE CONDITION NORMAL CONDITION/
REFERENCE VALUES
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
6-46 ENGINE GENERAL INFORMATION AND DIAGNOSIS
TABLE A-1 MALFUNCTION INDICATOR LAMP CIRCUIT CHECK - LAMP DOES
NOT COME “ON” AT IGNITION SWITCH ON (BUT ENGINE AT STOP)
WIRING DIAGRAM
CIRCUIT DESCRIPTION
When the ignition switch is turned ON, ECM causes the main relay to turn ON (close the contact point). Then,
ECM being supplied with the main power, turns ON the malfunction indicator lamp (MIL). When the engine
starts to run and no malfunction is detected in the system, MIL goes OFF but if a malfunction was or is detected,
MIL remains ON even when the engine is running.
INSPECTION
1. BATT fuse 3. IG METER fuse 5. Monitor connector 7. To ignition switch
2. Main fuse box 4. To battery 6. MIL
[A] : Case of TYPE A is shown
(See NOTE)[B] : Case of TYPE B is shown
(See NOTE)
1
12V5V
ECM
23
+BB
DA
C
BLK/WHT
BRN/WHT
BLK/RED
BLK/RED
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
BLK
DN
TS
GNDMON
PPL/WHTC42-27 [A]
C42-16 [A]
PNK/BLUC42-28 [A]
7 4
G02-1 [A]IG1
5
6IG1
WHT/GRN
BLK/WHT
G02-6 [A]
C41-5 C41-6 C41-10 C41-11 [B]C41-14 [B]
C41-15 [B]
C41-8 [B]
G02-9 [B]
PPL/WHT
NOTE:
For TYPE A and TYPE B, refer to NOTE in “ECM VOLTAGE VALUES TABLE” for applicable model.
Step Action Yes No
1 MIL Power Supply Check
1) Turn ignition switch ON.
Do other indicator/warning lights in combination
meter comes ON?Go to Step 2.“IG METER” fuse blown,
main fuse blown, ignition
switch malfunction, “BLK/
WHT” circuit between “IG
METER” fuse and combi-
nation meter or poor cou-
pler connection at
combination meter.
2 ECM Power and Ground Circuit Check
Does engine start?Go to Step 3. Go to TABLE A-5 ECM
POWER AND GROUND
CIRCUIT CHECK.
If engine is not cranked,
go to DIAGNOSIS in Sec-
tion 6G.
6E1-8 ENGINE AND EMISSION CONTROL SYSTEM
ENGINE & EMISSION CONTROL INPUT/OUTPUT TABLE
INPUTOUTPUT
ELECTRIC CONTROL DEVICE
FUEL LEVEL SENSOR (VEHICLE WITH IMMOBILIZER INDICATOR LAMP) For detecting fuel level DIAGNOSIS SWITCH (VEHICLE WITHOUT IMMOBILIZER INDICATOR LAMP)
BAROMETRIC PRESSURE SENSOR (VEHICLE WITH EGR VALVE)
STOP LAMP SWITCH
START SWITCH
IGNITION SWITCH
LIGHTING SWITCH
REAR DEFOGGER SWITCH
BLOWER SWITCH
A/C SWITCH
A/C EVAP TEMP. SENSOR
VSS
HEATED OXYGEN SENSOR-1
(VEHICLE WITH EGR VALVE)
HEATED OXYGEN SENSOR-2
(VEHICLE WITH IMMOBILIZER INDICATOR LAMP)For detecting deterioration of
three way catalytic convertor
IAT SENSOR
ECT SENSOR
TP SENSOR
MAP SENSOR
CMP SENSOR
CKP SENSOR
TEST SWITCH TERMINAL
(VEHICLE WITHOUT IMMOBILIZER INDICATOR LAMP)
KNOCK SENSOR (VEHICLE WITH EGR VALVE)
FUEL PUMP RELAY
FUEL INJECTOR
HO2S HEATER
IAC VALVE
IGNITION COIL WITH IGNITER
EGR VALVE (IF EQUIPPED)
EVAP CANISTER PURGE VALVE
A/C COMPRESSOR CLUTCH
RADIATOR FAN RELAY
MIL
MAIN RELAY
TRANSMISSION CONTROL MODULE SIGNAL FROM SENSOR, SWITCH AND CONTROL MODULE
6E1-10 ENGINE AND EMISSION CONTROL SYSTEM
1. CKP sensor 20. Blank 39. Ignition coil assembly (for No.1 and No.4 spark plugs)
2. CMP sensor 21. A/C switch 40. Ignition coil assembly (for No.2 and No.3 spark plugs)
3. VSS 22. A/C pressure switch 41. Stop lamp switch
4. MAP sensor 23. Immobilizer control module 42. Stop lamp
5. Knock sensor (if equipped) 24. Data link connector 43. Lighting switch
6. TP sensor 25. Injector No.1 44. Position lamp
7. ECT sensor 26. Injector No.2 45. Rear defogger switch
8. IAT sensor 27. Injector No.3 46. Rear defogger
9. Heated oxygen sensor-1 (if equipped) 28. Injector No.4 47. A/C compressor clutch (if equipped)
10. Heated oxygen sensor-2 (if equipped) 29. IAC valve 48. Ignition switch
11. A/C evaporator temp. sensor 30. EVAP canister purge valve 49. Main relay
12. Combination meter 31. Fuel pump relay 50. Transmission range switch (A/T)
13. Fuel level sensor (vehicle with immobilizer
indicator lamp)32. Fuel pump 51. Starting motor
14. TCM 33. Radiator fan relay 52. Shield wire
15. Transmission range switch 34. Radiator fan motor 53. Main fuse
16. ABS control module 35. EGR valve (if equipped) 54. Barometric pressure sensor
17. CO adjusting resistor (if equipped) 36. Malfunction indicator lamp 55. Immobilizer indicator lamp (if equipped)
18. Heater fan motor 37. Tachometer 56. Engine ground
19. Heater fan switch 38. Monitor connector (vehicle without immo-
bilizer indicator lamp)57. Body ground
6E1-12 ENGINE AND EMISSION CONTROL SYSTEM
1. CKP sensor 20. Blank 39. Ignition coil assembly (for No.1 and No.4 spark plugs)
2. CMP sensor 21. A/C switch 40. Ignition coil assembly (for No.2 and No.3 spark plugs)
3. VSS 22. A/C pressure switch 41. Stop lamp switch
4. MAP sensor 23. Immobilizer control module 42. Stop lamp
5. Knock sensor (if equipped) 24. Data link connector 43. Lighting switch
6. TP sensor 25. Injector No.1 44. Position lamp
7. ECT sensor 26. Injector No.2 45. Rear defogger switch
8. IAT sensor 27. Injector No.3 46. Rear defogger
9. Heated oxygen sensor-1 (if equipped) 28. Injector No.4 47. A/C compressor clutch (if equipped)
10. Blank 29. IAC valve 48. Ignition switch
11. A/C evaporator temp. sensor 30. EVAP canister purge valve 49. Main relay
12. Combination meter 31. Fuel pump relay 50. Transmission range switch (A/T)
13. Fuel level sensor (vehicle with immobilizer
indicator lamp)32. Fuel pump 51. Starting motor
14. TCM 33. Radiator fan relay 52. Shield wire
15. Transmission range switch 34. Radiator fan motor 53. Main fuse
16. ABS control module 35. EGR valve (if equipped) 54. Barometric pressure sensor
17. CO adjusting resistor (if equipped) 36. Malfunction indicator lamp 55. Immobilizer indicator lamp (if equipped)
18. Heater fan motor 37. Tachometer 56. Engine ground
19. Heater fan switch 38. Monitor connector (vehicle without immo-
bilizer indicator lamp)57. Body ground
ENGINE AND EMISSION CONTROL SYSTEM 6E1-15
ON-VEHICLE SERVICE
ACCELERATOR CABLE ADJUSTMENT
With accelerator pedal depressed fully (1), check clearance
between throttle lever (2) and lever stopper (3) (throttle body)
which should be within following specification.
If measured value is out of specification, adjust it to specification
with cable adjusting nut (4).
Accelerator cable adjustment clearance (with pedal
depressed fully)
“a” : 0.5 – 2.0 mm (0.02 – 0.07 in.)
IDLE SPEED/IDLE AIR CONTROL (IAC) DUTY
INSPECTION
Before idle speed/IAC duty check, make sure of the following.
Lead wires and hoses of Electronic Fuel Injection and engine
emission control systems are connected securely.
Accelerator cable has some play, that is, it is not tight.
Valve lash is checked and adjusted according to mainte-
nance schedule.
Ignition timing is within specification.
All accessories (wipers, heater, lights, A/C, etc.) are out of
service.
Air cleaner has been properly installed and is in good condi-
tion.
No abnormal air inhaling from air intake system.
After above items are all confirmed, check idle speed and IAC
duty as follows.
NOTE:
Before starting engine, place transmission gear shift
lever in “Neutral” (shift selector lever to “P” range for A/T
vehicle), and set parking brake and block drive wheels.