
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

6-1-42 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
RESISTANCE CHECK
1) Disconnect couplers (1) from ECM/PCM with ignition switch
OFF.
2) Check resistance between each pair of terminals of discon-
nected couplers (1) as listed in following table. CAUTION:
Never touch terminals of ECM/PCM itself or connect volt-
meter or ohmmeter (2).
CAUTION:
Be sure to connect ohmmeter (2) probe from wire har-
ness side of coupler.
Be sure to turn OFF ignition switch for this check.
Resistance in table represents that when parts temper-
ature is 20°C (68°F).
TERMINALS CIRCUIT STANDARD
RESISTANCECONDITION
E61-9 and E61-2 Main relay 79 – 95 Ω–
E61-22 and C51-3-20 A/C fan motor relay (if equipped) 75 – 110 ΩBattery disconnected
and ignition switch ON
E61-23 and C51-3-20 Fuel pump relay 79 – 95 Ω–
C51-3-6 and Body ground Ground Continuity –
C51-3-17 and Body ground Ground Continuity –
C51-1-1 and Body ground Shift solenoid B (A/T) 11 – 15 Ω–
C51-1-2 and Body ground Shift solenoid A (A/T)
C51-1-4 and C51-3-4 IAC valve (stepper motor coil 2) 25.5 – 33.5 Ω–
C51-1-5 and C51-3-4 IAC valve (stepper motor coil 1)
C51-1-8 and Body ground TCC solenoid (A/T) 11 – 15 Ω–
C51-1-15 and C51-3-4 EVAP canister purge valve 28 – 35 Ω–
C51-1-16 and C51-3-4 IAC valve (stepper motor coil 4) 25.5 – 33.5 Ω–
C51-1-17 and C51-3-4 IAC valve (stepper motor coil 3)
C51-2-1 and C51-3-4 Fuel injector No.2 13 – 16 Ω–
C51-2-2 and C51-3-4 Fuel injector No.1
C51-2-4, C51-2-5 and E61-9 Heater of HO2S-1 5.0 – 6.4 Ω–
C51-2-7 and Body ground Ground Continuity –
C51-2-8 and C51-3-4 Fuel injector No.4 13 – 16 Ω–
C51-2-9 and C51-3-4 Fuel injector No.3
C51-2-12 and C51-3-4 EGR valve (stepper motor coil 4) 20 – 24 Ω–
C51-2-13 and C51-3-4 EGR valve (stepper motor coil 3)
C51-2-14 and C51-3-4 EGR valve (stepper motor coil 2)
C51-2-15 and C51-3-4 EGR valve (stepper motor coil 1)
C51-2-16, C51- 2-17 and
E61-9Heater of HO2S-2 11.7 – 14.3 Ω–
C51-2-21 and C51-3-4 Fuel injector No.6
13 – 16 Ω–
C51-2-22 and C51-3-4 Fuel injector No.5

6-1-116 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Table B-1 Fuel Pump Circuit Inspection
WIRING DIAGRAM
INSPECTION
1. To ignition switch 4. Fuel pump relay
2. Main fuse 5. Fuel pump
3. Main relay 6. ECM (PCM)
CAUTION:
Check to make sure that connection is made between correct terminals.
Wrong connection can cause damage to ECM, wire harness etc.
Step Action Yes No
1 Fuel pump operation check :
1) Remove fuel filler cap.
2) Turn ON ignition switch.
Is fuel pump operation sound heard for 3 sec.
after ignition switch ON?Fuel pump circuit is in
good condition.Go to Step 2.
2 Fuel pump circuit check :
1) With ignition switch OFF, remove fuel pump
relay from connector.
2) Check for proper connection to relay at
each terminal.
3) If OK, using service wire, connect terminals
E07-7 and E07-8 of relay connector. (See
Fig.)
Is fuel pump heard to operate at ignition switch
ON?Go to Step 3.“BLU/BLK”, “PNK/BLK” or
“BLK” circuit open or fuel
pump malfunction.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-117
Fig. for Step 2
Table B-2 Fuel Injectors and Circuit Inspection
WIRING DIAGRAM
3 Fuel pump relay check :
1) Check fuel pump relay referring to “FUEL
PUMP RELAY INSPECTION” in Section
6E2.
Is it in good condition?“BLK/WHT” or “WHT/
GRN” circuit open or poor
E61-23 connection.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.Replace fuel pump relay. Step Action Yes No
1. Fuel pump relay connector
1. To ignition switch 4. Injector No.1 7. Injector No.4 10. ECM (PCM)
2. Main fuse 5. Injector No.2 8. Injector No.5
3. Main relay 6. Injector No.3 9. Injector No.6

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-119
Table B-3 Fuel Pressure Inspection
SYSTEM DIAGRAM
Special tool
(A) : 09912-58441
(B) : 09912-58431
(C) : 09919-58421
INSPECTION
1. Injector 4. Fuel filter
2. Delivery pipe 5. Fuel pump
3. Fuel pressure regulator
NOTE:
Before using the following flow table, check to make sure that battery voltage is higher than 11 V. If
battery voltage is low, pressure becomes lower than specification even if fuel pump and line are in
good condition.
Step Action Yes No
1 1) Install fuel pressure gauge, referring to
“FUEL PRESSURE INSPECTION” in Sec-
tion 6E2.
2) Operate fuel pump.
Is fuel pressure then 270 – 310 kPa
(2.7 – 3.1 kg/cm
2, 38.4 – 44.0 psi)?Go to Step 2. Go to Step 5.
2
Is 200 kPa (2.0 kg/cm
2, 28.4 psi) or higher fuel
pressure retained for 1 minute after fuel pump
is stopped at Step 1?Go to Step 3. Go to Step 4.

6-1-120 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
3 1) Start engine and warm it up to normal oper-
ating temperature.
2) Keep it running at specified idle speed.
Is fuel pressure then within 210 – 260 kPa
(2.1 – 2.6 kg/cm
2, 29.8 – 37.0 psi)?Normal fuel pressure. Clogged vacuum passage
for fuel pressure regula-
tor or faulty fuel pressure
regulator.
4 Is there fuel leakage from fuel feed line hose,
pipe or joint?Fuel leakage from hose,
pipe or joint.Go to Step 10.
5 Was fuel pressure higher than spec. in Step 1? Go to Step 6. Go to Step 7.
6 1) Disconnect fuel return hose from fuel pipe
and connect new hose to it.
2) Put the other end of new return hose into
approved gasoline container.
3) Operate fuel pump.
Is specified fuel pressure obtained then?Restricted fuel return
hose or pipe.Faulty fuel pressure regu-
lator.
7 Was no fuel pressure applied in Step 1? Go to Step 8. Go to Step 9.
(Low pressure is mea-
sured.)
8 With fuel pump operated and fuel return hose
blocked by pinching it, is fuel pressure applied?Faulty fuel pressure regu-
lator.Shortage of fuel or fuel
pump or its circuit defec-
tive (Refer to “TABLE B-
1”).
9 1) Operate fuel pump.
2) With fuel return hose blocked by pinching it,
check fuel pressure.
Is it 450 kPa (4.5 kg/cm
2, 64.0 psi) or more?Faulty fuel pressure regu-
lator.Clogged fuel filter,
restricted fuel feed hose
or pipe, faulty fuel pump
or fuel leakage from hose
connection in fuel tank.
10 1) Disconnect fuel return hose from fuel pipe
and connect new hose to it.
2) Put the other end of new return hose into
approved gasoline container.
3) Check again if specified fuel pressure is
retained.
While doing so, does fuel come out return
hose?Faulty fuel pressure regu-
lator.Fuel leakage from injec-
tor, faulty fuel pump
(faulty check valve in fuel
pump) or fuel leakage
from fuel pressure regula-
tor diaphragm. Step Action Yes No

6A2-20 ENGINE MECHANICAL (H27 ENGINE)
12) Install oil pan and oil pump strainer.
Refer to “OIL PAN AND OIL PUMP STRAINER” in this sec-
tion.
13) Install cylinder head cover.
Refer to “CYLINDER HEAD COVER” in this section.
14) Install exhaust manifold.
Refer to “EXHAUST MANIFOLD” in this section.
15) Install radiator outlet pipe, radiator, cooling fan and water
hose.
Refer to “COOLING WATER PIPES OR HOSES”, “RADIA-
TOR” and “COOLING FAN AND FAN CLUTCH” in Section
6B.
16) Install throttle body and intake manifold.
Refer to “THROTTLE BODY AND INTAKE MANIFOLD” in
this section.
17) Adjust water pump drive belt tension.
Refer to “COOLING FAN BELT TENSION CHECK AND
ADJUSTMENT” in Section 6B.
18) Adjust power steering pump drive belt tension.
Refer to “POWER STEERING PUMP DRIVE BELT” in Sec-
tion 3B1.
19) Adjust accelerator cable play and A/T throttle cable play.
Refer to “ACCELERATOR CABLE ADJUSTMENT” and “A/T
THROTTLE CABLE ADJUSTMENT (A/T VEHICLE)” in Sec-
tion 6E2.
20) Check to ensure that all removed parts are back in place.
Reinstall any necessary parts which have not been rein-
stalled.
21) Refill engine with engine oil, referring to “ENGINE OIL
CHANGE” in Section 0B.
22) Refill cooling system referring to “COOLING SYSTEM
FLUSH AND REFILL” in Section 6B.
23) Refill front differential housing with gear oil if drained, refer-
ring to “MAINTENANCE SERVICE” in Section 7E.
24) Connect negative cable at battery.
25) Check ignition timing and adjust as necessary, referring to
“IGNITION TIMING CHECK AND ADJUSTMENT” in Section
6F2.
26) Verify that there is no fuel leakage, water leakage, oil leak-
age and exhaust gas leakage at each connection.
27) Check wheel alignment, referring to “STEERING ANGLE” in
Section 3A.

ENGINE MECHANICAL (H27 ENGINE) 6A2-27
12) Disconnect the following electric lead wires :
•Injector wire coupler
•CMP sensor coupler
•Ignition coil couplers
•CKP sensor coupler
•MAP sensor coupler
•TP sensor (1) coupler
•IAC valve (2) coupler
•Earth wire (3) from surge tank
•EVAP canister purge valve coupler
•EGR valve coupler
•Oxygen sensor -1 and -2 couplers referring to “Exhaust Man-
ifold” in this section
•Coolant temperature sensor coupler
•Knock sensor coupler
•Generator wires
•Starter wires
•Oil pressure wire
•P/S pump wire
•Earth wire from generator bracket
•Engine block heater (if equipped)
13) Remove clamps and brackets.
14) Disconnect the following hoses :
•Heater hose from heater water pipe
•Heater hose from water outlet cap
•EVAP canister hose from canister pipe
•Brake booster vacuum hose
15) Remove EVAP canister purge valve (5).
16) Disconnect the following hoses at the location shown in the
figure :
•Fuel feed hose (1) from fuel feed pipe
•Fuel return hose from (2) fuel return pipe
17) Remove P/S pump assembly. Refer to “POWER STEERING
PUMP” in Section 3B1.
18) Remove A/C compressor assembly. Refer to “COMPRES-
SOR ASSEMBLY” in Section 1B.
19) Remove steering shaft lower assembly. Refer to “STEERING
LOWER SHAFT ASSEMBLY” in Section 3C1.
20) Raise vehicle.
21) Remove front differential housing with differential from chas-
sis if equipped. Refer to “DISMOUNTING” in Section 7E.
22) Remove exhaust No.1 pipe. Refer to “EXHAUST MANI-
FOLD” in this section.
23) Remove exhaust manifold stiffener from transmission.
4. Clamp bracket
6. EGR valve
7. Heater hose
2
14
3
75
6