Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-25
Excessive detonation
(The engine makes
sharp metallic knocks
that change with throt-
tle opening.
Sounds like pop corn
popping.)Engine overheating Refer to “Overheating” of this table.
Faulty spark plug Spark plugs in Section 6F.
Clogged fuel filter and fuel lines Diagnostic Flow Table B-3
Malfunctioning EGR valve (if equipped) EGR system in Section 6E.
Poor performance of knock sensor, ECT
sensor or MAP sensorKnock sensor in this section, ECT
sensor or MAP sensor in Section 6E.
Faulty injector Diagnostic Flow Table B-1
Faulty ECM Inspection of ECM and its circuit in
this section.
Excessive combustion chamber deposits Piston and cylinder head in Section
6A1.
Overheating
Inoperative thermostat Thermostat in Section 6B.
Faulty A/C condenser fan motor or its cir-
cuitA/C condenser fan control system
check in Section 6E.
Loose or slip water pump belt ITEM1-1 Drive belt inspection and
change in Section 0B.
Poor water pump performance Water pump in Section 6B.
Clogged or leaky radiator Radiator in Section 6B.
Improper engine oil grade ITEM1-3 Engine oil and oil filter
change in Section 0B.
Clogged oil filter or oil strainer Oil pressure check in Section 6A1.
Poor oil pump performance Oil pressure check in Section 6A1.
Dragging brakes Diagnosis Table in Section 5.
Slipping clutch Diagnosis Table in Section 7C.
Blown cylinder head gasket Valves and cylinder head in Section
6A1.
Poor gasoline mileage
Faulty ignition coil Ignition coil assembly in Section 6F.
Fuel pressure out of specification Diagnostic Flow Table B-3
Faulty TP sensor, ECT sensor or MAP
sensorTP sensor, ECT sensor or MAP sen-
sor in Section 6E.
Faulty injector Diagnostic Flow Table B-1
Faulty ECM Inspection of ECM and its circuit in
this section.
Malfunctioning EGR valve (if equipped) EGR system in Section 6E.
High idle speed Refer to item “Improper Engine Idle
Speed” previously outlined.
Low compression Previously outlined.
Poor valve seating Valves and cylinder head in Section
6A1.
Dragging brakes Diagnosis Table in Section 5.
Slipping clutch Diagnosis Table in Section 7C.
Thermostat out of order Thermostat in Section 6B.
Improper tire pressure Refer to Section 3F. Condition Possible Cause Reference Item
Downloaded from www.Manualslib.com manuals search engine 6-30 ENGINE GENERAL INFORMATION AND DIAGNOSIS
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 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 using 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 value 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 corrections to the air / fuel mixture computation. A value of 0 indi-
cates no correction, a value greater than 0 means an enrichment correction, and a value less than 0 implies 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. 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.BRAKE SWIgnition switch
ONBrake pedal is depressing ON
Brake pedal is releasing OFF
BLOWER FANIgnition switch
ONBlower fan switch ON ON
Blower fan switch OFF OFF
A/C MAG CLUTCHIgnition switch
ONA/C operating ON
A/C not operating OFF SCAN TOOL DATA CONDITION REFERENCE VALUES
Downloaded from www.Manualslib.com manuals search engine 6-36 ENGINE GENERAL INFORMATION AND DIAGNOSIS
For TYPE A (See NOTE)
E1918EGR valve (stepper motor coil 1, if
equipped)10 – 14 VIgnition switch ON position leaving engine
OFF
19 Ignition coil #2––
20 Ignition coil #1––
21 Fuel injector NO.2 10 – 14 V Ignition switch ON
22 Power source for sensors 4.75 – 5.25 V Ignition switch ON
23 Crankshaft position sensor0 – 0.8 or
4 – 5 VIgnition switch ON position
24–– –
25 Knock sensor About 2.5 VAt specified idle speed after engine
warmed up
26 Manifold absolute pressure sensor 3.3 – 4.0 VIgnition switch ON
Barometric pressure : 100 kPa
(760 mmHg)
27–– –
28EGR valve (stepper motor coil 4, if
equipped)10 – 14 VIgnition switch ON position leaving engine
OFF
29EGR valve (stepper motor coil 2, if
equipped)10 – 14 VIgnition switch ON position leaving engine
OFF
30–– –
31 Fuel injector NO.3 10 – 14 V Ignition switch ON TERMINAL
NO.CIRCUIT NORMAL
VOLTAGECONDITION
NOTE:
See NOTE in “ECM TERMINAL VOLTAGE VALUES TABLE” for applicable model.
TERMINAL
NO.CIRCUIT NORMAL
VOLTAGECONDITION
E181 A/C compressor clutch 0 V Ignition switch ON
2 Malfunction indicator lamp10 – 14 V Engine running
0 – 1.0 V Ignition switch ON leaving engine OFF
3 Data link connector 10 – 14 V Ignition switch ON
4 Heater of HO2S-2 (if equipped) 10 – 14 V Ignition switch ON
5 Power source 10 – 14 V Ignition switch ON
6 Power source 10 – 14 V Ignition switch ON
7 Power source for buck-up 10 – 14 V Ignition switch ON and OFF
8Immobilizer indicator lamp
(with immobilizer indicator lamp)10 – 14 V Engine running
0 – 1.0 V Ignition switch ON leaving engine OFF
Duty output terminal (without
immobilizer indicator lamp)0 – 1.0 V Ignition switch ON
9–– –
10 Main relay10 – 14 V Ignition switch OFF
0.4 – 1.5 V Ignition switch ON
11 Tachometer––
12 Data link connector 4 – 5 V Ignition switch ON
13 Heated oxygen sensor-2 Refer to DTC P0130 diag. flow table
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For TYPE B (See NOTE)
E1814Diag. Switch terminal (without
immobilizer indicator lamp)4 – 5 V Ignition switch ON
15Test switch terminal (without immo-
bilizer indicator lamp)4 – 5 V Ignition switch ON
16 A/C (input) signal10 – 14 VIgnition switch ON
A/C switch OFF
0 – 2 VIgnition switch ON
A/C switch ON
17 Lighting switch10 – 14 V Lighting switch ON
0 – 1.3 V Lighting switch OFF
18A/C condenser fan motor relay
(if equipped)0 – 1.0 V A/C is operating
10 – 14 V A/C is not operating
19 Fuel pump relay0 – 1 V For 2 seconds after ignition switch ON
10 – 14 V After the above time
20 Sensor ground––
21Throttle opening signal for
TCM (A/T)Indication
deflection
repeated
0 V and
10 – 14 VIgnition switch ON
22Fuel level sensor (gauge)
(with immobilizer indicator lamp)0 – 2 VIgnition switch ON
Fuel tank fully filled
4.5 – 7.5 VIgnition switch ON
Fuel tank emptied
23–– –
24 Heater blower switch0 – 2.0 VIgnition switch ON and heater blower
switch ON
10 – 14 VIgnition switch ON and heater blower
switch OFF TERMINAL
NO.CIRCUIT NORMAL
VOLTAGECONDITION
NOTE:
See NOTE in “ECM TERMINAL VOLTAGE VALUES TABLE” for applicable model.
TERMINAL
NO.CIRCUIT NORMAL
VOLTAGECONDITION
E181 A/C compressor clutch 0 V Ignition switch ON
2–– –
3–– –
4–– –
5 Power source 10 – 14 V Ignition switch ON
6 Power source 10 – 14 V Ignition switch ON
7 Power source for buck-up 10 – 14 V Ignition switch ON and OFF
8Immobilizer indicator lamp
(with immobilizer indicator lamp)10 – 14 V Engine running
0 – 1.0 V Ignition switch ON leaving engine OFF
Duty output terminal (without
immobilizer indicator lamp)0 – 1.0 V Ignition switch ON
Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-41
Resistance Check
1) Disconnect ECM couplers (1) from ECM with ignition switch
OFF.
2) Check resistance between each terminal of couplers discon-
nected. CAUTION:
Never touch terminals of ECM itself or connect voltmeter
or ohmmeter (2).
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 20 °C (68 °F).
1. ECM coupler disconnected
2. Ohmmeter
TERMINALS CIRCUIT STANDARD RESISTANCE
E19-7 to E17-9
(For TYPE A) (See NOTE)HO2S-1 heater 5 – 6.4 Ω
E19-7 to E18-11
(For TYPE B) (See NOTE)
E18-4 to E17-9
(For TYPE A) (See NOTE)HO2S-2 heater 11.7 – 14.3 Ω
E19-9 to E19-2 No.1 injector 12.0 – 13.0 Ω
E19-21 to E19-2 No.2 injector 12.0 – 13.0 Ω
E19-31 to E19-2 No.3 injector 12.0 – 13.0 Ω
E19-8 to E19-2 No.4 injector 12.0 – 13.0 Ω
E19-28 to E19-2 EGR valve (stepper motor coil 4) 20 – 24 Ω
E19-17 to E19-2 EGR valve (stepper motor coil 3) 20 – 24 Ω
E19-29 to E19-2 EGR valve (stepper motor coil 2) 20 – 24 Ω
E19-18 to E19-2 EGR valve (stepper motor coil 1) 20 – 24 Ω
E19-4 to E19-2 EVAP canister purge valve 30 – 34 Ω
E18-19 to E17-9 (For
TYPE A) (See NOTE)Fuel pump relay 70 – 110 Ω
E18-19 to E18-11 (For
TYPE B) (See NOTE)
E18-1 to Body ground A/C compressor clutch 3 – 4.5 Ω
E18-18 to E19-2 A/C condenser fan control relay 70 – 110 Ω
E18-10 to E18-7 Main relay 70 – 110 Ω
E19-1 to Body ground Ground Continuity
E19-2 to Body ground Ground Continuity
E19-3 to Body ground Ground Continuity
NOTE:
For TYPE A and TYPE B, refer to the NOTE in “ECM Terminal Voltage Values Table” for applicable
model.
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Table B-5 A/C Signal Circuits Check (Vehicle with A/C)
1. A/C compressor magnet clutch 4. A/C condenser fan 7. Evaporator temp. sensor
2. A/C switch 5. Refrigerant pressure switch [A] : Case of TYPE A is shown (See NOTE)
3. Blower fan 6. ECT sensor [B] : Case of TYPE B is shown (See NOTE)
NOTE:
For TYPE A and TYPE B, refer to the NOTE in “ECM Terminal Voltage Values Table” for applicable
model.
Downloaded from www.Manualslib.com manuals search engine ENGINE MECHANICAL (M13 ENGINE) 6A1-5
10) Disengage clutch (1) (to lighten starting load on engine) for
M/T vehicle, and depress accelerator pedal (2) all the way to
make throttle fully open.
11) Crank engine with fully charged battery, and read the highest
pressure on compression gauge.
Compression pressure specification
12) Carry out Steps 9) through 11) on each cylinder to obtain 4
readings.
13) After checking, install spark plugs and ignition coil assem-
blies (1) with high-tension cord (2).
14) Connect ignition coil couplers (3).
15) Connect fuel injector wires (4) at the coupler.
16) Check cylinder head upper cover gasket for deterioration and
then install it into groove of cylinder head upper cover (1)
securely.
17) Install cylinder head upper cover with gasket on to cylinder
head cover.
18) Connect accelerator cable (2) to clamp (3) (For left hand
steering vehicle only).
NOTE:
For measuring compression pressure, crank engine at
least 250 rpm by using fully charged battery.
If check results are below the limit valve, check instal-
lation condition for special tool.
Standard1400 kPa
(14.0 kg/cm
2, 199.0 psi)
Limit1100 kPa
(11.0 kg/cm
2, 156.0 psi)
Max. difference between
any two cylinders100 kPa
(1.0 kg/cm
2, 14.2 psi)
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4) Drain engine oil by removing drain plug.
5) Remove clutch housing (torque converter housing for A/T
vehicle) lower plate (1).
6) Remove oil pan and then oil pump strainer (1) from cylinder
block.
CLEAN
Inside of oil pan and oil pump strainer screen.
Clean sealing surface on oil pan and cylinder block.
Remove oil, old sealant and dust from sealing surface.