6-24 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
ConditionPossible CauseReferring Item
OverheatingInoperative thermostat
Poor water pump performance
Clogged or leaky radiator
Improper engine oil grade
Clogged oil filter or oil strainer
Poor oil pump performance
Faulty radiator fan control system
Dragging brakes
Slipping clutch
Blown cylinder head gasketThermostat in Section 6B
Water pump in Section 6B
Radiator in Section 6B
Engine oil and oil filter change in
Section 0B
Oil pressure check in Section 6A
Oil pressure check in Section 6A
Radiator fan control system in
Section 6E1
Trouble diagnosis in Section 5
Trouble diagnosis in Section 7C
Cylinder head in Section 6A
Poor gasoline
mileageIgnition system out of order
Leaks or loose connection of high-tension cord
Faulty spark plug (improper gap, heavy deposits
and burned electrodes, etc.)
Engine and emission control system out of
order
High idle speed
Poor performance of TP sensor, ECT sensor or
MAP sensor
Faulty fuel injector
Faulty fuel injector resistor
Faulty ECM (PCM)
Low compression
Others
Poor valve seating
Dragging brakes
Slipping clutch
Thermostat out of order
Improper tire pressure
High-tension cords in Section 6F
Spark plugs in Section 6F
Refer to item “Improper engine
idle speed” previously outlined
TP sensor, ECT sensor or MAP
sensor in Section 6E1
Diagnostic Flow Table B-1
Fuel injector resistor in Section 6E1
Previously outlined
Valves inspection in Section 6A
Trouble diagnosis in Section 5
Trouble diagnosis in Section 7C
Thermostat in Section 6B
Refer to Section 3F
Excessive engine
oil consumptionOil leakage
Blown cylinder head gasket
Leaky camshaft oil seals
Oil entering combustion chamber
Sticky piston ring
Worn piston and cylinder
Worn piston ring groove and ring
Improper location of piston ring gap
Worn or damaged valve stem seal
Worn valve stem
Cylinder head in Section 6A
Camshaft in Section 6A
Piston cleaning in Section 6A
Pistons and cylinders inspection
in Section 6A
Pistons inspection in Section 6A
Pistons assembly in Section 6A
Valves removal and installation in
Section 6A
Valves inspection in Section 6A
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-25
ConditionPossible CauseReferring Item
Engine hesitates
(Momentary lack of
response as
accelerator is
depressed.
Can occur at all
vehicle speeds.
Usually most severe
when first trying to
make vehicle move,
as from a stop sign.)Ignition system out of order
Spark plug faulty or plug gap out of adjustment
Leaky high-tension cord
Fuel system out of order
Fuel pressure out of specification
Engine and emission control system out of
order
Poor performance of TP sensor, ECT sensor or
MAP sensor
Faulty fuel injector
Faulty ECM (PCM)
Engine overheating
Low compression
Spark plugs in Section 6F
High-tension cords in Section 6F
Diagnostic Flow Table B-3
Trouble diagnosis in Section 6
TP sensor, ECT sensor or MAP
sensor in Section 6E1
Diagnostic Flow Table B-1
Refer to “Overheating” section
Previously outlined
Surge
(Engine power
variation under
steady throttle or
cruise.
Feels like vehicle
speeds up and down
with no change in
accelerator pedal.)Ignition system out of order
Leaky or loosely connected high-tension cord
Faulty spark plug (excess carbon deposits,
improper gap, and burned electrodes, etc.)
Fuel system out of order
Variable fuel pressure
Kinky or damaged fuel hose and lines
Faulty fuel pump (clogged fuel filter)
Engine and emission control system out of
order
Poor performance of MAP sensor
Faulty fuel injector
Faulty ECM (PCM)
High-tension cords in Section 6F
Spark plugs in Section 6F
Diagnostic Flow Table B-3
MAP sensor in Section 6E1
Diagnostic Flow Table B-1
Excessive
detonation
(Engine makes
continuously
sharp metallic
knocks that change
with throttle opening.
Sounds like pop corn
popping.)Engine overheating
Ignition system out of order
Faulty spark plug
Loose connection of high-tension cord
Fuel system out of order
Clogged fuel filter (faulty fuel pump) or fuel lines
Air inhaling from intake manifold or throttle body
gasket
Engine and emission control system out of
order
Poor performance of ECT sensor or MAP sensor
Faulty fuel injector
Faulty ECM (PCM)
Excessive combustion chamber depositsRefer to “Overheating” section
Spark plugs in Section 6F
High-tension cords in Section 6F
Diagnostic Flow Table B-1 or B-2
Trouble diagnosis in Section 6
ECT sensor or MAP sensor in
Section 6E1
Diagnostic Flow Table B-1
Piston and cylinder head cleaning
in Section 6A
6-26 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
ConditionPossible CauseReferring Item
Engine has no
powerIgnition system out of order
Faulty spark plug
Faulty ignition coil with ignitor
Leaks, loose connection or disconnection of
high-tension cord
Engine overheating
Fuel system out of order
Clogged fuel hose or pipe
Malfunctioning fuel pump
Air inhaling from intake manifold gasket or
throttle body gasket
Engine and emission control system out of
order
Maladjusted accelerator cable play
Poor performance of TP sensor, ECT sensor or
MAP sensor
Faulty fuel injector
Faulty ECM (PCM)
Low compression
Others
Dragging brakes
Slipping clutch
Spark plugs in Section 6F
Ignition coil in Section 6F
High-tension cords in Section 6F
Refer to “Overheating” section
Diagnostic Flow Table B-3 in
Section 6
Diagnostic Flow Table B-2
Accelerator cable play in Section
6E1
TP sensor, ECT sensor or MAP
sensor in Section 6E1
Diagnostic Flow Table B-1
Previously outlined
Trouble diagnosis in Section 5
Trouble diagnosis in Section 7C
6-30 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
SCAN TOOL DATACONDITIONNORMAL CONDITION /
REFERENCE VALUES
DESIRED IDLEAt idling with no load after warming up, M / T850 r / min(DESIRED IDLE SPEED)
gg,
at neutral, A / T at “P” range850 r / min
TP SENSOR VOLT
(THROTTLE POSITIONIgnition switch
ON / engine
Throttle valve fully closedMore than 0.2 V(
SENSOR OUTPUT
VOLTAGE)ON / engine
stoppedThrottle valve fully openLess than 4.8 V
INJ PULSE WIDTH
(FUEL INJECTIONAt specified idle speed with no load after
warming up0.8 – 2.3 msec.(
PULSE WIDTH)At 2500 r / min with no load after warming up0.8 – 2.3 msec.
IAC FLOW DUTY (IDLE
AIR CONTROL FLOW
DUTY)
At idling with no load after warming up20 – 40%
TOTAL FUEL TRIMAt specified idle speed after warming up–35 – +35%
BATTERY VOLTAGEIgnition switch ON / engine stop10 – 14 V
CANIST PRG DUTY
(EVAP CANISTER
PURGE FLOW DUTY)
At specified idle speed after warming up0 – 100%
CLOSED THROT POS
(CLOSED THROTTLEThrottle valve at idle positionON(CLOSED THROTTLE
POSITION)Throttle valve opens larger than idle positionOFF
FUEL CUTWhen engine is at fuel cut conditionONFUEL CUTOther than fuel cut conditionOFF
RAD FAN
(RADIATOR FANIgnition switch
ON
Engine coolant temp.:
Lower than 92.5C
(199F)
OFF
(
CONTROL RELAY)ONEngine coolant temp.:
97.5C (208F) or higherON
ELECTRIC LOAD
Ignition switch ON / Headlight, small light,
heater fan and rear window defogger all
turned OFF
OFF
ELECTRIC LOADIgnition switch ON / Headlight, small light,
heater fan or rear window defogger turned
ON
ON
A / C SWITCH
Engine running after warming up, A / C not
operatingOFF
A/C SWITCHEngine running after warming up, A / C
operatingON
PSP SWITCH
Engine running at idle speed and steering wheel
at straight-ahead position.OFF
(if equipped).Engine running at idle speed and steering wheel
turned to the right or left as far as it stops.ON
FUEL TANK LEVEL––––––––––––0 – 100%
BAROMETRIC PRESS––––––––––––Display the barometric pressure
FUEL PUMP
Within 3 seconds after ignition switch ON or
engine runningON
Engine stop at ignition switch ON.OFF
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-33
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 ful-
ly 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
RAD FAN
(RADIATOR FAN CONTROL RELAY, ON / OFF)
ON : Command for radiator fan control relay opera-
tion being output.
OFF : Command for relay operation not being out-
put.
ELECTRIC LOAD (ON / OFF)
ON : Headlight, small light, heater fan or rear win-
dow defogger ON signal inputted.
OFF : Above electric loads all turned OFF.
A / C SWITCH (ON / OFF)
ON : Command for A / C operation being output
from ECM (PCM) to A / C amplifier.
OFF : Command for A / C operation not being output.
FUEL TANK LEVEL (%)
This parameter indicates approximate fuel level in the
fuel tank. As the detectable range of the fuel level sen-
sor is set as 0 to 100%, however, with some models
whose fuel tank capacity is smaller, the indicated fuel
level may be only 70% even when the fuel tank is full.
PSP SWITCH (ON / OFF)
ON : PSP switch detects P / S operation (high PS
pressure).
OFF : PSP switch not detects P / S operation.
BAROMETRIC PRESS (kPa, inHg)
This parameter represents a measurement of baro-
metric air pressure and is used for altitude correction
of the fuel injection quantity and ISC actuator control.
FUEL PUMP (ON / OFF)
ON is displayed when the ECM (or PCM) activates the
fuel pump via the fuel pump relay switch.
VSS (A / T) (km / h, MPH)
If is computed by using pulse signals from vehicle
(output) speed sensor on automatic transmission.
TRANS RANGE (TRANSMISSION RANGE
SENSOR, P, R, N, D, 2 OR L)
It is indicated transmission range detected by trans-
mission range sensor.
SHIFT SOL 1-CON (SHIFT SOLENOID-1,
ON / OFF)
ON : ON command being output to shift solenoid-1
OFF : ON command not being output.
SHIFT SOL 2-CON (SHIFT SOLENOID-2,
ON / OFF)
ON : ON command being output to shift solenoid-2
OFF : ON command not being output.
SHIFT SOL 1-MON (SHIFT SOLENOID-1,
ON / OFF)
The monitor result of the shift solenoid-1 circuit is dis-
played.
ON : Electricity being passed to shift solenoid-1 or
circuit open.
OFF : Electricity not being passed or circuit short.
SHIFT SOL 2-MON (SHIFT SOLENOID-2,
ON / OFF)
The monitor result of the shift solenoid-2 circuit is dis-
played.
ON : Electricity being passed to shift solenoid-2 or
circuit open.
OFF : Electricity not being passed or circuit short.
THROT POS LEVEL (THROTTLE POSITION
LEVEL FOR A / T, “0”, “1”, “2”, “3”, “4”, “5”, “6”
or “7”)
This parameter indicates which level (zone) the
throttle valve opening is in. The throttle opening is di-
vided into 8 levels (zones) from “0” (about idle posi-
tion) to “7” (about full open) and signals are assigned
to each opening level (zone). ECM (PCM) control the
automatic gear change of the automatic transmission
by using these signals according to the signal from
the TP sensor.
GEAR POSITION
This parameter indicates the A / T gear position which
is computed on signals from the Transmission Range
Switch, VSS, TP Sensor, and so forth.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-35
CONNECTOR “C02”
TER-
MINALWIRE
COLORCIRCUITSTANDARD
VOLTAGECONDITION
1BECM (PCM) ground––
2W/BlPower source10 – 14 VIgnition switch ON
3—Blank——
4—Blank——
5—Blank——
6—Blank——
7R/GEVAP canister purge valve10 – 14 VIgnition switch ON
8G/OrShift solenoid B (A / T)
0 VIgnition switch ON, selector lever at “P”
range
8G/OrShift solenoid-B (A / T)
10 – 14 VIgnition switch ON, selector lever at “D”
range
9G/WShift solenoid A (A / T)
0 VIgnition switch ON, selector lever at “P”
range
9G/WShift solenoid-A (A / T)
10 – 14 VIgnition switch ON, selector lever at “D”
range
10OrIgniter (IGT)——
11Gr / YISC actuator——
12Y/BFuel injector10 – 14 VIgnition switch ON
13B/BlGround for injector——
14WPower source for back-up10 – 14 VIgnition switch ON and OFF
15W/BlPower source10 – 14 VIgnition switch ON
16Gr / BISC actuator relay0.3 – 1.0 VIgnition switch ON
17V/YMalfunction indicator lamp0.2 – 2.0 VIgnition switch ON17V/YMalfunction indicator lamp10 – 14 VWhen engine running
18V/GImmobilizer indicator lamp0.2 – 2.0 VIgnition switch ON18V/GImmobilizer indicator lamp10 – 14 VWhen engine running at idle
19Lg / BHeater of H02S-210 – 14 VIgnition switch ON
20BlRadiator fan control relay
10 – 14 VIgnition switch ON, Engine coolant
temp: Below 91.5C (197F)
20BlRadiator fan control relay
0.3 – 1.0 VIgnition switch ON, Engine coolant
temp: 96.0C (205F) or higher
21P/WFuelpumprelay0.3 – 1.3 VFor 2 seconds after ignition switch ON21P/WFuel pump relay10 – 14 VAfter the above time
22Bl / BMain relay0.4 – 1.5 VIgnition switch ON
23–Blank——
24Gr / RISC actuator——
25Y/REFE heater relay10 – 14 VIgnition switch ON
26B/RGround for injector——
6-38 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
1 2
1. ECM (PCM)
coupler disconnected
2. Ohmmeter
RESISTANCE CHECK
1) Disconnect ECM (PCM) couplers from ECM (PCM) with ignition
switch OFF.
CAUTION:
Never touch terminals of ECM (PCM) itself or connect
voltmeter or ohmmeter.
2) Check resistance between each terminal of couplers discon-
nected.
CAUTION:
Be sure to connect ohmmeter probe from wire harness
side of coupler.
Be sure to turn OFF ignition switch for this check.
Resistance in table below represents that when parts
temperature is 20C (68F).
TERMINALSCIRCUITSTANDARD RESISTANCE
C01-8 to C03-20H02S-1 heater11.7 – 14.3 Ω
C02-19 to C03-20H02S-2 heater11.7 – 14.3 Ω
C02-12 to C02-2 / 15Fuel injector2.4 – 3.6 Ω
C02-7 to C02-2 / 15EVAP canister purge valve30 – 34 Ω
C02-21 to C03-20Fuel pump relay100 – 120 Ω
C02-16 to C02-2 / 15ISC actuator relay100 – 120 Ω
C02-25 to C02-2 / 15EFE heater relay100 – 120 Ω
C02-8 to Body groundShift solenoid-B8 – 20 Ω
C02-9 to Body groundShift solenoid-A8 – 20 Ω
C02-20 to C02-2 / 15Radiator fan control relay100 – 120 Ω
C02-22 to C02-14Main relay100 – 120 Ω
C02-1 to Body groundGroundContinuity
C02-13 to Body groundGroundContinuity
C02-26 to Body groundGroundContinuity
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-39
INFORMATION SENSORS
-1. MAP sensor
-2. TP sensor
-3. IAT sensor
-4. ECT sensor
-5. Heated oxygen sensor-1
-6. VSS
-7. Ignition coil
-8. Battery
-9. CMP sensor (in Distributor)
-10. A/C contoller (if equipped)
-11. CKP sensor
-12. CTP switch (in ISC actuator)
-13. Heated oxygen sensor-2OTHERS
A: ECM (PCM)
B: Main relay
C: EVAP canister
D: Injector resistor
E: EFE heater
F: Electric load diode CONTROL DEVICES
a: Fuel injector
b: EVAP canister purge valve
c: Fuel pump relay
d: Malfunction indicator lamp
e: ISC actuator
f: Radiator fan control relay
g: Igniter
h: EFE heater relay
i: ISC actuator relay
COMPONENT LOCATION