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.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-29
EGR VALVE (%)
This parameter indicates opening rate of EGR valve which controls the amount of EGR flow.
A/C SWITCH (ON/OFF)
ON : Command for operation being output from A/C amplifier to compressor.
OFF : Command for operation not being output.
PSP SWITCH (ON/OFF)
ON : PSP switch detects P/S operation. (high P/S pressure)
OFF : PSP switch not detects P/S operation.
PNP SIGNAL (Transmission Range Switch, P/N or D range)
Whether the transmission range switch (P/N position switch) at P or N range or at R, D, 2 or L range is displayed.
If at P or N range, “P/N range” is displayed and if at R, D, 2 or L range, “D range” is displayed.
FUEL TANK LEVEL (%)
This parameter indicates approximate fuel level in the fuel tank. As the detectable range of the fuel level sensor
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.
ELECTRIC LOAD (ON/OFF)
ON : Small light switch ON or rear window defogger switch ON.
OFF : Small light switch OFF and rear window defogger switch OFF.
VSS (4-A/T) (km/h, MPH)
It is computed by using pulse signals from vehicle speed sensor on 4-speed automatic transmission.
THROT POS LEVEL (Throttle Position Level For 4-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 divided into 8 levels (zones) from “0” (about idle position) to “7” (about full open) and sig-
nals are assigned to each opening level (zone). PCM controls the automatic gear change of the automatic trans-
mission by using these signals according to the signal from the TP sensor.
GEAR POSITION (1ST, 2ND, 3RD or 4TH)
The gear position is determined on the basis of the command state signals generated from PCM to shift sole-
noids A and B (#1 and #2) and displayed as shown in the table below.
SHIFT SOL #1 CON/MON (Shift Solenoid #1, A Command/monitor, ON/OFF)
CON-ON : ON command being output to shift solenoid #1, A.
CON-OFF : ON command not being output.
MON-ON : Electricity being passed to shift solenoid #1, A.
MON-OFF : Electricity not being passed.SHIFT SOLENOID-A SHIFT SOLENOID-B
DISPLAY1ST ON OFF
2ND ON ON
3RD OFF ON
4TH OFF OFF
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.
6-1-34 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Poor gasoline mileage
Faulty spark plug (improper gap, heavy depos-
its, and burned electrodes, etc.)Spark plugs in Section 6F2.
Fuel pressure out of specification “DIAG. FLOW TABLE B-3” in this
section.
Faulty TP sensor, ECT sensor or MAF sensor TP sensor, ECT sensor or MAF
sensor in Section 6E2.
Faulty EGR system “DTC P0400 DIAG. FLOW TABLE”
in this section.
Faulty injector Fuel injector 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.
Poor valve seating Valves inspection in Section 6A2.
Dragging brakes Diagnosis in Section 5.
Slipping clutch Diagnosis in Section 7C1.
Thermostat out of order Thermostat in Section 6B.
Improper tire pressure Diagnosis in Section 3.
Excessive engine oil
consumptionSticky piston ring Piston cleaning in Section 6A2.
Worn piston and cylinder Cylinders, pistons and piston rings
inspection in Section 6A2.
Worn piston ring groove and ring Pistons and piston rings inspection
in Section 6A2.
Improper location of piston ring gap Pistons installation in Section 6A2.
Worn or damaged valve stem seal Valves and cylinder head in Sec-
tion 6A2.
Worn valve stem Valves inspection in Section 6A2.
Low oil pressure
Improper oil viscosity Engine oil and oil filter change in
Section 0B.
Malfunctioning oil pressure switch Oil pressure switch inspection in
Section 8.
Clogged oil strainer Oil pan and oil pump strainer clean-
ing in Section 6A2.
Functional deterioration of oil pump Oil pump in Section 6A2.
Worn oil pump relief valve Oil pump in Section 6A2.
Excessive clearance in various sliding parts “INSPECTION” for each parts in
Section 6A2. Condition Possible Cause Correction
6-1-36 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Inspection of PCM (ECM) and its Circuits
PCM (ECM) and its circuits can be checked at PCM (ECM) wiring
couplers by measuring voltage and resistance.
VOLTAGE CHECK
1) Remove PCM (ECM) cover from bracket referring to PCM
(ECM) REMOVAL.
2) Check voltage at each terminal of couplers connected.CAUTION:
PCM/ECM cannot be checked by itself. It is strictly pro-
hibited to connect voltmeter or ohmmeter to PCM (ECM)
with couplers disconnected from it.
NOTE:
As each terminal voltage is affected by the battery volt-
age, confirm that it is 11 V or more when ignition switch
is ON.
1. PCM (ECM)
2. PCM (ECM) connector (Viewed from harness side)
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