
6-1-26 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
PNP SIGNAL (Transmis-
sion Range Switch) (for 4-
A/T)With ignition switch ON, selector lever in “P”
or “N” positionP/N Range
✱
With ignition switch ON, selector lever in “R”,
“D”, “2” or “L” positionD Range
FUEL TANK LEVEL Ignition switch ON 0 – 100 %✱
ELECTRIC LOAD Ignition ON, small light OFF OFF✱
Ignition switch ON, small light ON ON✱
VSS (Vehicle speed sen-
sor) (for 4-A/T)At stop.
0 km/h 0 MPH✱
GEAR POSITION (for 4-
A/T)Ignition switch ON, selector lever is shifted at
“R”, “D”, “2” or “L” range and vehicle stops.1st✱
THROT POS LEVEL
(Throttle position level for
4-A/T)“0” (about idle position), “1”,“2”,“3”,“4”,“5”,“6” or “7” (about full open)
appears according to throttle valve opening.✱
SHIFT SOL #1 (A)
CON (Shift solenoid #1
command signal)
MON (Shift solenoid #1
monitor) (for 4-A/T)Ignition switch ON
Selector lever is shifted at “P”, “R”, “N”, “D”,
“2” or “L” range.
Vehicle stops.ON✱
SHIFT SOL #2 (B)
CON (Shift solenoid #2
command signal)
MON (Shift solenoid #2
monitor) (for 4-A/T)Ignition switch ON
Selector lever is shifted at “P”, “R”, “N”, “D”,
“2” or “L” range.
Vehicle stops.OFF✱
TCC SOL (for 4-A/T)
CON (Torque converter
clutch solenoid command
signal)
MON (Torque converter
clutch solenoid monitor)Ignition switch ON
Selector lever is shifted at “P”, “R”, “N”, “D”,
“2” or “L” range.
Vehicle stops.OFF✱
TRANS RANGE
(for 4-A/T)Ignition switch ON, selector lever is at “P”,
“R”, “N”, “D”, “2” or “L” range.P, R, N, D, 2 or L✱
BRAKE SW
(Brake, stop lamp, switch)
(for 4-A/T)Ignition switch ON, Brake pedal is released. OFF
✱
Ignition switch ON, Brake pedal is
depressed.ON
O/D OFF SW
(Overdrive cut switch)Ignition switch ON, Overdrive cut switch OFF OFF
✱
Ignition switch ON, Overdrive cut switch ON ON
MODE SELECT SW
(Power/Normal change
switch) (for 4-A/T)Ignition switch ON, P/N change switch is at
normal position.NORMAL
✱
Ignition switch ON, P/N change switch is at
power position.POWER
4WD-L SW
(4WD low switch)Ignition switch ON, Transfer lever is shifted
at “4H” or “2H” position.OFF
✱
Ignition switch ON, Transfer lever is shifted
at “4L” position.ON SCAN TOOL DATA CONDITIONNORMAL CONDITION/
REFERENCE VALUEOTHER

6-1-28 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
TP SENSOR VOLT (TP Sensor Output Voltage, V)
Throttle Position Sensor reading provides throttle valve opening information in the from of voltage.
O2S B1 S1 (HO2S Bank 1 Sensor 1 Output Voltage, V) / O2S B2 S1 (HO2S Bank 2 Sensor 1 Output
Voltage, V)
It indicates output voltage of HO2S SENSOR 1 installed on exhaust manifold (pre-catalyst).
O2S B1 S2 (HO2S Bank 1 Sensor 2 Output Voltage, V) / O2S B2 S2 (HO2S Bank 2 Sensor 2 Output
Voltage, V)
If indicates output voltage of HO2S SENSOR 2 installed on exhaust pipe (post-catalyst). It is used to detect cat-
alyst deterioration.
FUEL SYSTEM B1 (Fuel System Bank 1 Status) / Fuel System B2 (Fuel System Bank 2 Status)
Air/fuel ratio feedback loop status displayed as one of the followings.
OPEN : Open loop-has not yet satisfied conditions to go closed loop.
CLOSED : Closed loop-using oxygen sensor(s) as feedback for fuel control.
OPEN-DRIVE COND : Open loop due to driving conditions (Power enrichment, etc.).
OPEN SYS FAULT : Open loop due to detected system fault.
CLOSED-ONE O2S : Closed loop, but fault with at least one oxygen sensor may be using single oxygen sensor
for fuel control.
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%.
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.
CANIST PRG DUTY (EVAP Canister Purge Flow Duty, %)
This parameter indicates valve ON (valve open) time rate within a certain set cycle of EVAP canister purge valve
which controls the amount of EVAP purge.
VEHICLE SPEED (km/h, MPH)
It is computed based on pulse signals from vehicle speed sensor on transfer or transmission.
FUEL CUT (ON/OFF)
ON : Fuel being cut (output signal to injector is stopped).
OFF : Fuel not being cut.
MAP (Manifold Absolute Pressure, mmHg, kPa)
This parameter indicates the pressure in the intake manifold absolute pressure.
A/C CONDENSER FAN (ON/OFF)
This parameter indicates the state of the A/C Condenser Fan control signal.
BLOWER FAN (ON/OFF)
This parameter indicates the state of the blower fan motor switch.

6-1-30 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
SHIFT SOL #2 CON/MON (Shift Solenoid #2, B Command/monitor, ON/OFF)
CON-ON : ON command being output to shift solenoid #2, B.
CON-OFF : ON command not being output.
MON-ON : Electricity being passed to shift solenoid #2, B.
MON-OFF : Electricity not being passed.
TCC SOL CON/MON (Torque Converter Clutch Solenoid Command/monitor, ON/OFF)
CON-ON : ON command being output to TCC solenoid.
CON-OFF : ON command not being output.
MON-ON : Electricity being passed to TCC solenoid.
MON-OFF : Electricity not being passed.
TRANS RANGE (Transmission Range, P, R, N, D, 2 or L)
It indicates transmission range according to transmission range switch signal.
BRAKE SW (Brake, Stop Lamp, Switch, ON/OFF)
OFF : Brake pedal is released.
ON : Brake pedal is depressed.
O/D OFF SW (Overdrive Cut Switch, ON/OFF)
OFF : Overdrive cut switch OFF.
ON : Overdrive cut switch ON.
MODE SELECT SW (Power/normal Change Switch, Power/normal)
POWER : Switch button is at POWER position.
NORMAL : Switch button is at NORMAL position.
4WD-L SW (4WD-LOW Switch, ON/OFF)
ON : Transfer lever is shifted to 4L position.
OFF : Transfer lever is shifted to 4H or 2H position.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-31
Engine Diagnosis Table
Perform troubleshooting referring to following table when ECM (PCM) has detected no DTC and no abnormality
has been found in visual inspection and engine basic inspection previously.
Condition Possible Cause Correction
Hard starting
(Engine cranks OK)Faulty idle air control system “DIAG. FLOW TABLE B-4” in this
section.
Faulty ECT sensor or MAF sensor ECT sensor or MAF sensor in Sec-
tion 6E2.
Faulty ECM (PCM) Inspection of ECM (PCM) and its
circuit in this section.
Low compression Compression check in Section
6A2.
Faulty hydraulic valve lash adjuster Valve lash adjuster in Section 6A2.
Compression leak from valve seat Valves inspection in Section 6A2.
Sticky valve stem Valves inspection in Section 6A2.
Weak or damaged valve springs Valves spring inspection in Section
6A2.
Compression leak at cylinder head gasket Cylinder head inspection in Section
6A2.
Sticking or damaged piston ring Piston ring inspection in Section
6A2.
Worn piston, ring or cylinder Cylinders, pistons and piston rings
inspection in Section 6A2.
Malfunctioning PCV valve PCV system inspection in Section
6E2.
Engine has no power
Engine overheating Refer to “OVERHEATING” in this
table.
Defective spark plug Spark plugs in Section 6F2.
Faulty ignition coil with ignitor Ignition coil in Section 6F2.
Fuel pressure out of specification
(dirty fuel filter, dirty or clogged fuel hose or
pipe, malfunctioning fuel pressure regulator,
malfunctioning fuel pump)“DIAG. FLOW TABLE B-3” in this
section.
Maladjusted TP sensor installation angle TP sensor in Section 6E2.
Faulty EGR system “DTC P0400 DIAG. FLOW TABLE”
in this section.
Faulty injector Fuel injector in Section 6E2.
Faulty TP sensor, ECT sensor or MAF sensor TP sensor, ECT sensor or MAF
sensor in Section 6E2.
Faulty ECM (PCM) Inspection of ECM (PCM) and its
circuit in this section.
Low compression Refer to the same item in “HARD
STARTING” of this table.
Dragging brakes Diagnosis in Section 5.
Slipping clutch Diagnosis in Section 7C1.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-33
Surges
(Engine power varia-
tion under steady
throttle or cruise.
Feels like the vehicle
speeds up and down
with no change in the
accelerator pedal.)Defective spark plug
(excess carbon deposits, improper gap, and
burned electrodes, etc.)Spark plugs in Section 6F2.
Variable fuel pressure
(clogged fuel filter, kinky or damaged fuel hose
and line, faulty fuel pressure regulator)“DIAG. FLOW TABLE B-3” in this
section.
Faulty EGR system “DTC P0400 DIAG. FLOW TABLE”
in this section.
Faulty MAF sensor MAF sensor in Section 6E2.
Faulty injector Fuel injector in Section 6E2.
Faulty ECM (PCM) Inspection of ECM (PCM) and its
circuit in this section.
Excessive detonation
(The engine makes
sharp metallic knocks
that change with throt-
tle opening. Sounds
like pop corn pop-
ping.)Engine overheating Refer to “OVERHEATING” in this
table.
Faulty spark plug Spark plugs in Section 6F2.
Improper ignition timing Ignition timing in Section 6F2.
Clogged fuel filter and fuel lines Fuel pressure check in Section
6E2.
Faulty EGR system “DTC P0400 DIAG. FLOW TABLE”
in this section.
Faulty ECT sensor or MAF sensor ECT sensor or MAF sensor in Sec-
tion 6E2.
Faulty injector Fuel injector in Section 6E2.
Faulty ECM (PCM) Inspection of ECM (PCM) and its
circuit in this section.
Excessive carbon deposits in combustion
chamberPiston and cylinder head cleaning
in Section 6A2.
Poor knock sensor performance “DTC P0325 DIAG. FLOW TABLE”
in this section.
Overheating
Inoperative thermostat Thermostat in Section 6B.
Poor water pump performance Water pump in Section 6B.
Clogged or leaky radiator Radiator in Section 6B.
Improper engine oil grade Engine oil and oil filter change in
Section 0B.
Clogged oil filter or oil strainer Oil pressure check in Section 6A2.
Poor oil pump performance Oil pressure check in Section 6A2.
Dragging brakes Diagnosis in Section 5.
Slipping clutch Diagnosis in Section 7C1.
Blown cylinder head gasket Cylinder head inspection in Section
6A2. Condition Possible Cause Correction

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-37
TERMINAL CIRCUIT NORMAL VOLTAGE CONDITION
E61-1Power source for CO adjusting
resistor (if equipped)10 – 14 V Ignition switch ON
E61-2 Power source for back up 10 – 14 V Ignition switch ON and OFF
E61-3 – – –
E61-4Cruise control module
(throttle opening signal)
(if equipped)Ignition switch ON, Voltage varies as specified at figure in
cruise control diagnosis of Section 8E while throttle valve is
opened gradually.
E61-5Duty output terminal
(vehicle with monitor connector)0 – 1 V Ignition switch ON
E61-6 Tachometer 0 – 1 V Ignition switch ON, engine stops
E61-7Malfunction indicator lamp
(“SERVICE ENGINE SOON” lamp)0 – 2.5 V Ignition switch ON, engine stops
10 – 14 V Engine running
E61-8 A/C cut signal (if equipped)0 – 1.5 V A/C is not operating
10 – 14 V A/C is operating
E61-9 Main relay10 – 14 V Ignition switch OFF
0 – 2 VIgnition switch ON or for 4 seconds
after ignition switch OFF
E61-10 CO adjusting resistor (if equipped) – –
E61-11 – – –
E61-12Data link connector (5V)
(Vehicle with monitor connector)4 – 6 V Ignition switch ON
E61-13 Data link connector (12V) 10 – 14 V Scan tool not connected to DLC
E61-14Test switch terminal
(Vehicle with monitor connector)10 – 14 V Ignition switch ON
E61-15 Rear defogger switch (if equipped)0 – 1.5 VIgnition switch ON, rear defogger
switch OFF
10 – 14 VIgnition switch ON, rear defogger
switch
E61-16 Heater blower switch10 – 14 VIgnition switch ON, heater blower
switch OFF
0 – 1.5 VIgnition switch ON, heater blower
switch ON
E61-17 A/C signal (if equipped)10 – 14 VIgnition switch ON, A/C switch or
heater blower switch OFF
0 – 1 VIgnition switch ON, A/C switch ON
and heater blower switch ON
E61-18 – – –
E61-19 “4WD” lamp0 – 1 VIgnition switch ON, Transfer lever :
4H or 4L range
10 – 14 VIgnition switch ON, Transfer lever :
2H range
E61-20 “O/D OFF” lamp (A/T vehicle)0 – 1 VFor 4 sec. after ignition switch ON
or overdrive cut switch ON
10 – 14 VAfter 4 sec. from ignition switch ON
and overdrive cut switch OFF
E61-21 “POWER” lamp (A/T vehicle)0 – 1 VIgnition switch ON, P/N change
switch : POWER mode
10 – 14 VIgnition switch ON, P/N change
switch : NORMAL mode

6-1-38 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
E61-22A/C condenser fan motor relay
(if equipped)10 – 14 VIgnition switch ON, A/C not oper-
ated and Engine coolant temp. :
less than 113°C, 235°F
E61-23 Fuel pump relay0 – 2.5 VFor 3 sec. after ignition switch ON
or while engine running
10 – 14 VAfter 3 sec. from ignition switch ON
with engine stopped
E61-24Ground for CO adjusting resistor
(if equipped)––
E61-25 – – –
E61-26 – – –
E61-27 – – –
E61-28 Fuel level sensor 0 – 6 VIgnition switch ON
Voltage depends on fuel level
E61-29Diag. switch terminal
(vehicle with monitor connector)10 – 14 V Ignition switch ON
E61-30 ABS control module 10 – 14 V Ignition switch ON
E61-31Power/Normal change switch
(A/T vehicle)0 – 1 VIgnition switch ON, P/N change
switch : POWER mode
10 – 14 VIgnition switch ON, P/N change
switch : NORMAL mode
E61-32 Lighting switch0 – 1 VIgnition switch ON, lighting switch
OFF
10 – 14 VIgnition switch ON, lighting switch
ON
E61-33 Overdrive cut switch (A/T vehicle)10 – 14 VIgnition switch ON, overdrive cut
switch released
0 – 1 VIgnition switch ON, overdrive cut
switch pressed
E61-34 Stop lamp switch0 – 1 VBrake pedal released (switch OFF),
Ignition switch ON
10 – 14 VBrake pedal depressed (switch ON),
Ignition switch ON
E61-35 Cruise control module (if equipped) 10 – 14 V Ignition switch ON
C51-3-1 Intake air temp. sensor 2.2 – 3.0 VIgnition switch ON, Sensor ambient
temp. : 20°C, 68°F
C51-3-2 Engine coolant temp. sensor 0.5 – 0.9 VIgnition switch ON, Engine coolant
temp. : 80°C, 176°F
C51-3-3 Knock sensor About 2.5 VWith engine running at idle after
warned up
C51-3-4 Power source 10 – 14 V Ignition switch ON
C51-3-5 Ground for MAF sensor – –
C51-3-6 Ground – –
C51-3-7 4WD switch0 – 1 VIgnition switch ON, Transfer lever :
4H or 4L range
10 – 14 VIgnition switch ON, Transfer lever :
2H range
C51-3-8 Manifold absolute pressure sensor 3.3 – 4.3 V Ignition switch ON and engine stops TERMINAL CIRCUIT NORMAL VOLTAGE CONDITION

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-39
C51-3-9 Throttle position sensor0.5 – 1.2 VIgnition switch ON, Throttle valve at
idle position
3.4 – 4.7 VIgnition switch ON, Throttle valve at
full open position
C51-3-10 Mass air flow sensor1.0 – 1.6 V Ignition switch ON and engine stops
1.7 – 2.0 V With engine running at idle speed
C51-3-11Heated oxygen sensor-1 (bank 1)
(if equipped)Deflects between
over and under 0.45 VWhile engine running at 2,000 r/min.
for 1 min. or longer after warmed up
C51-3-12 Ground for TP sensor – –
C51-3-13 Power source for TP sensor
4.75 – 5.25 V Ignition switch ON
C51-3-14 Power source for MAP sensor
C51-3-15 Power source 10 – 14 V Ignition switch ON
C51-3-16 – – –
C51-3-17 Ground – –
C51-3-18Pressure switch in 4WD air pump
assembly10 – 14 VIgnition switch ON, Transfer lever :
4H or 4L range
0 – 1 VIgnition switch ON, Transfer lever :
2H range
C51-3-19 – – –
C51-3-20 Ignition switch 10 – 14 V Ignition switch ON
C51-3-21Heated oxygen sensor-1 (bank 2)
(if equipped)Deflects between over
and under 0.45 VWhile engine running at 2,000 r/min.
for 1 min. or longer after warmed up
C51-3-22Heated oxygen sensor-2 (bank 1)
(if equipped)Deflects between over
and under 0.45 VWhile engine running at 2,000 r/min.
for 1 min. or longer after warmed up
C51-3-23Heated oxygen sensor-2 (bank 2)
(if equipped)Deflects between over
and under 0.45 VWhile engine running at 2,000 r/min.
for 1 min. or longer after warmed up
C51-3-24 Ground for ECT sensor – –
C51-3-25 Ground for IAT sensor, MAP sensor – –
C51-3-26 Ground for CMP sensor – –
C51-1-1 Shift solenoid B (A/T vehicle) 0 – 1 V Ignition switch ON
C51-1-2 Shift solenoid A (A/T vehicle) 10 – 14 V Ignition switch ON
C51-1-3 – – –
C51-1-4 IAC valve (stepper motor coil 2) – –
C51-1-5 IAC valve (stepper motor coil 1) – –
C51-1-6Transmission range switch “R”
(A/T vehicle)10 – 14 VIgnition switch ON, selector lever :
“R” range
0 – 1 VIgnition switch ON, selector lever :
Other than “R”
C51-1-7Transmission range switch “P”
(A/T vehicle)10 – 14 VIgnition switch ON, selector lever :
“P” range
0 – 1 VIgnition switch ON, selector lever :
Other than “P” range
C51-1-8 TCC solenoid (A/T vehicle) 0 – 1 V Ignition switch ON
C51-1-9 4WD air pump assembly10 – 14 VIgnition switch ON, Transfer lever :
4H or 4L range
0 – 1 VIgnition switch ON, Transfer lever :
2H range TERMINAL CIRCUIT NORMAL VOLTAGE CONDITION