6E2-6 ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE)
Air Intake System
The main components of the air intake system are air cleaner, mass air flow sensor, air cleaner, intake air pipe,
throttle body, intake collector, idle air control valve and intake manifold.
The air (by the amount corresponding to the throttle valve opening and engine speed) is filtered by the air
cleaner, passes through the throttle body, is distributed by the intake manifold and finally drawn into each com-
bustion chamber.
When the idle air control valve is opened according to the signal from ECM (PCM), the air bypasses the throttle
valve through bypass passage and is finally drawn into the intake manifold.
“A” : Air 1. Air cleaner 6. PCV hose 11. Breather hose 16. IAC valve and fast idle control system
“B” : EGR 2. IAT sensor 7. Brake booster 12. MAF sensor 17. FIA valve
“C” : Engine coolant 3. Resonator 8. Fuel pressure
regulator hose13. EGR valve 18. Thermo - WAX
4. Intake manifold 9. Intake air pipe 14. TP sensor
5. Intake collector 10. Throttle body 15. IAC valve
18
10
17
15
16
ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE) 6E2-7
Fuel Delivery System
The fuel delivery system consists of the fuel tank, fuel pump, fuel filter, fuel pressure regulator, delivery pipe and
fuel injectors.
The fuel in the fuel tank is pumped up by the fuel pump, filtered by the fuel filter and fed under pressure to each
injector through the delivery pipe.
As the fuel pressure applied to the injector (the fuel pressure in the fuel feed line) is always kept a certain
amount higher than the pressure in the intake manifold by the fuel pressure regulator, the fuel is injected into the
intake port of the cylinder head when the injector opens according to the injection signal from ECM (PCM).
The fuel relieved by the fuel pressure regulator returns through the fuel return line to the fuel tank.
[A] : Fuel 1. Fuel tank 5. Fuel return line 9. Fuel injector
[B] : Air 2. Fuel pump 6. Fuel pressure regulator 10. Fuel delivery pipe
3. Fuel filter 7. Vacuum hose for fuel pressure regulator 11. Throttle valve
4. Fuel feed line 8. Intake manifold surge tank
6E2-8 ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE)
Electronic Control System
The electronic control system consists of 1) various sensors which detect the state of engine and driving condi-
tions, 2) ECM (PCM) which controls various devices according to the signals from the sensors and 3) various
controlled devices.
Functionally, it is divided into the following sub systems:
•Fuel injection control system
•Heated oxygen sensor heater control system (if equipped)
•Idle air control system
•Fuel pump control system
•Evaporative emission control system
•Ignition control system
•EGR system (if equipped)
Also, with A/T model, PCM controls A/T.
INFORMATION SENSORS CONTROLLED DEVICES OTHERS
1. IAT sensor a : A/C condenser fan motor relay (if equipped) A : Main fuse box
2. MAP sensor (if equipped) b : Ignition coil assemblies B : ECM (PCM)
3. Heated oxygen sensor (sensor 1) (if equipped) c : EVAP canister purge valve C : Data link connector
4. ECT sensor d : EGR valve (if equipped) D : Combination meter
5. TP sensor e : Idle air control valve E : Fuse box
6. MAF sensor f : Injectors F : EVAP canister
7. Camshaft position sensor (CMP sensor) g : Malfunction indicator lamp
8. ABS control module h : Fuel pump relay
9. Crankshaft position sensor (CKP sensor) (if equipped) i : Main relay
10. Power steering pressure switch (PSP switch) j : Oxygen sensor heater relay (if equipped)
11. CO adjusting resistor (if equipped)
12. Monitor connector (if equipped)
13. Transmission range switch (A/T)
14. Knock sensor
NOTE:
Above figure shows left-hand steering vehicle. For right-hand steering vehicle, parts with (*) are
installed at the side of symmetry.
6E2-10 ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE)
TERMINAL ARRANGEMENT OF ECM (PCM) CONNECTOR (VIEWED FROM HARNESS SIDE)
1. Fuel injector No.1 17.“O/D OFF” lamp (A/T) 34. Power steering pressure switch
2. Fuel injector No.2 18.“POWER” lamp (A/T) 35. Stop lamp switch (Brake pedal switch)
3. Fuel injector No.3 18-1.“4WD” lamp (4WD) 36. Lighting switch
4. Fuel injector No.4 18-2. 4WD air pump assembly (4WD) 37. Rear defogger switch (if equipped)
4-1. Fuel injector No.5 19. 4WD switch (4WD) 38. Heater blower motor (if equipped)
4-2. Fuel injector No.6 20. Power/Normal change switch (A/T) 39. A/C control module (amplifier)
5. EGR valve (if equipped) 21. O/D cut switch (A/T) 40. ABS control module
6. Idle air control 21-1. 4WD low switch (4WD) 41. Heated oxygen sensor-1 (Bank1) (if equipped)
7. EVAP canister purge valve 22. Main relay 41-1. Heated oxygen sensor-1 (Bank2) (if equipped)
8. Ignition coil for No.1 23. Transmission range switch (Park/Neutral
Position Switch) or clutch pedal position switch42. Heater oxygen sensor-2 (Bank1) (if equipped)
8-1. Ignition coil for No.2 24. Starter magnetic switch 42-1. Heater oxygen sensor-2 (Bank2) (if equipped)
9. Ignition coil for No.3 24-1. Cruise control module (if equipped) 43. Intake air temp. sensor
9-1. Ignition coil for No.4 25. Vehicle speed sensor 44. Engine coolant temp. sensor
10. Ignition coil for No.5 26. Combination meter 45. Throttle position sensor
10-1. Ignition coil for No.6 27. Data link connector 46. CO adjusting resistor (if equipped)
11. Fuel pump relay 28. TCC solenoid (A/T) 47. Manifold absolute pressure sensor (if
equipped)
12. Fuel pump 29. Shift solenoid-B (A/T) 48. Mass air flow sensor
13. A/C condenser fan relay (if equipped) 30. Shift solenoid-A (A/T) 49. Camshaft position sensor
14. A/C condenser fan motor (if equipped) 31. Transmission range switch (sensor) (A/T) 50. Crankshaft position sensor (if equipped)
15. Knock sensor 32. A/T input speed sensor (A/T) 51. Monitor connector (if equipped)
16. Malfunction indicator lamp 33. A/T vehicle (output) speed sensor (A/T) 52. Engine control module
(Powertrain control module)
TERMINAL CIRCUIT TERMINAL CIRCUIT TERMINAL CIRCUIT
E61-1 Power source for CO adjusting resistor
(if equipped)E61-13 Data link connector E61-25—
E61-2 Power source for back up E61-14 Test switch terminal (if equipped) E61-26—
E61-3—E61-15 Rear defogger switch (if equipped) E61-27—
E61-4 Cruise control module
(Throttle opening signal)E61-16 Heater blower switch E61-28—
E61-5 Duty output terminal (if equipped) E61-17 A/C signal (if equipped) E61-29 Diag. switch terminal (if equipped)
E61-6 Tachometer E61-18—E61-30 ABS control module (if equipped)
E61-7 MIL (“SERVICE INGINE SOON” lamp) E61-19“4WD” lamp E61-31 Power/Normal change switch (A/T)
E61-8 A/C cut signal (if equipped) E61-20“O/D OFF” lamp (A/T) E61-32 Lighting switch
E61-9 Main relay E61-21“POWER” lamp (A/T) E61-33 O/D cut switch (A/T)
E61-10 CO adjusting resistor (if equipped) E61-22 A/C fan motor relay (if equipped) E61-34 Stop lamp switch (Brake pedal switch)
E61-11—E61-23 Fuel pump relay E61-35 Cruise control module (if equipped)
E61-12—E61-24 Ground for CO adjusting resistor (if
equipped)
ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE) 6E2-11
TERMINAL CIRCUIT TERMINAL CIRCUIT TERMINAL CIRCUIT
C51-3-1 Intake air temp. (IAT) sensor C51-3-13 Power source for TP sensor C51-3-25 Ground for IAT sensor, MAP sensor and
oxygen sensor (if equipped)
C51-3-2 Engine coolant temp. (ECT) sensor C51-3-14 Power source for MAP sensor (if
equipped)C51-3-26 Ground for CMP sensor
C51-3-3 Knock sensor C51-3-15 Power source
C51-3-4 Power source C51-3-16—
C51-3-5 Ground for MAF sensor C51-3-17 Ground
C51-3-6 Ground C51-3-18 Pressure switch in 4WD air pump
assembly
C51-3-7 4WD switch C51-3-19—
C51-3-8 Manifold absolute pressure (MAP)
sensor (if equipped)C51-3-20 Ignition switch
C51-3-9 Throttle position (TP) sensor C51-3-21 Heated oxygen sensor-1 (Bank2) (if
equipped)
C51-3-10 Mass air flow (MAF) sensor C51-3-22 Heated oxygen sensor-2 (Bank1) (if
equipped)
C51-3-11 Heated oxygen sensor-1 (Bank1) (if
equipped)C51-3-23 Heated oxygen sensor-2 (Bank2) (if
equipped)
C51-3-12 Ground for TP sensor C51-3-24 Ground for ECT sensor
TERMINAL CIRCUIT TERMINAL CIRCUIT TERMINAL CIRCUIT
C51-1-1 Shift solenoid-B (A/T) C51-1-13 CMP sensor C51-1-25 Power steering pressure switch
C51-1-2 Shift solenoid-A (A/T) C51-1-14 Vehicle speed sensor C51-1-26 4WD Low switch
C51-1-3—C51-1-15 EVAP canister purge valve C51-1-27 Transmission range switch “L” (A/T)
C51-1-4 IAC valve (stepper motor coil 2) C51-1-16 IAC valve (stepper motor coil 4) C51-1-28 Transmission range switch “2” (A/T)
C51-1-5 IAC valve (stepper motor coil 1) C51-1-17 IAC valve (stepper motor coil 3)
C51-1-6 Transmission range switch “R” (A/T) C51-1-18 Transmission range switch “D” (A/T)
C51-1-7 Transmission range switch “P” (A/T) C51-1-19 Transmission range switch “N” (A/T)
C51-1-8 TCC solenoid (A/T) C51-1-20 Shield wire ground for A/T output
speed sensor
C51-1-9 4WD air pump assembly C51-1-21 Shield wire ground for A/T input
speed sensor
C51-1-10 A/T input speed sensor (–) C51-1-22 A/T output speed sensor (–)
C51-1-11 A/T input speed sensor (+) C51-1-23 A/T output speed sensor (+)
C51-1-12 CMP sensor C51-1-24 Engine start signal
TERMINAL CIRCUIT TERMINAL CIRCUIT TERMINAL CIRCUIT
C51-2-1 Fuel injector No.2 C51-2-13 EGR valve (stepper motor coil 3) (if
equipped)C51-2-25 Ignition coil assembly for No.4
C51-2-2 Fuel injector No.1 C51-2-14 EGR valve (stepper motor coil 2) (if
equipped)C51-2-26 Ignition coil assembly for No.3
C51-2-3—C51-2-15 EGR valve (stepper motor coil 1) (if
equipped)C51-2-27 Ignition coil assembly for No.2
C51-2-4 Heater of HO2S-1 (Bank1) (if equipped) C51-2-16 Heater of HO2S-2 (Bank1) (if equipped) C51-2-28 Ignition coil assembly for No.1
C51-2-5 Heater of HO2S-1 (Bank2) (if equipped) C51-2-17 Heater of HO2S-2 (Bank2) (if equipped) C51-2-29—
C51-2-6—C51-2-18—C51-2-30 Ground for CKP sensor shield wire (if
equipped)
C51-2-7 Ground C51-2-19 CKP sensor (+) (if equipped)
C51-2-8 Fuel injector No.4 C51-2-20 CKP sensor (–) (if equipped)
C51-2-9 Fuel injector No.3 C51-2-21 Fuel injector No.6
C51-2-10—C51-2-22 Fuel injector No.5
C51-2-11—C51-2-23 Ignition coil assembly for No.6
C51-2-12 EGR valve (stepper motor coil 4) (if
equipped)C51-2-24 Ignition coil assembly for No.5
ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE) 6E2-13
On-Vehicle Service
General
When hoses are disconnected and system components are removed for service, reinstall components properly,
and route and connect hoses correctly after service. Refer to figure on previous page for proper routing of
hoses.
1. Brake booster hose pipe 8. EGR pipe (if equipped) 15. EVAP canister
2. Vacuum hose for fuel pressure regulator 9. Exhaust manifold 16. Tank pressure control valve
3. Fuel pressure regulator 10. Heated oxygen sensor 17. To fuel tank
4. MAP sensor (if equipped) 11. EGR valve (if equipped) 18. Cap
5. Engine coolant hose 12. PCV hose [A]: Vehicle without monitor connector
6. EVAP canister purge valve 13. IAC valve [B]: Vehicle with monitor connector
7. Breather hose 14. IAC hose
ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE) 6E2-23
Fuel Delivery System
Fuel pressure inspection
1) Relieve fuel pressure in fuel feed line referring to “FUEL
PRESSURE RELIEF PROCEDURE” in Section 6-1.
2) Disconnect fuel feed hose from (3) delivery fuel feed pipe (1).
3) Connect special tools and hose (2) between fuel feed hose
and fuel feed pipe as shown in figure, and clamp hose
securely to ensure no leaks occur during checking.
Special tool
(A) : 09912-58441
(B) : 09912-58431
(C) : 09912-58490
4) Check that battery voltage is above 11 V.
5) Turn ignition switch ON to operate fuel pump and after 3 sec-
onds turn it OFF. Repeat this 3 or 4 times and then check
fuel pressure.
6) Start engine.
7) Measure fuel pressure at idling.
If measure pressure doesn’t satisfy specification, refer to
“Diagnostic Flow Table B-3” in Section 6-1 and check each
possibly defective part. Replace if found defective.
Fuel pressure specification: CAUTION:
A small amount of fuel may be released when fuel feed
hose is removed. Place container under the fuel feed
hose or fuel feed pipe with a shop cloth so that released
fuel is caught in container or absorbed in cloth. Place
that cloth in an approved container.
CONDITION FUEL PRESSURE
With fuel pump operating and
engine stopped270 – 310 kPa
2.7 – 3.1 kg/cm
2
38.4 – 44.0 psi
At specified idle speed 210 – 260 kPa
2.1 – 2.6 kg/cm
2
29.8 – 37.0 psi
With 1 min. after engine (fuel pump)
stop (Pressure reduces as time
passes)over 200 kPa
2.0 kg cm
2
28.4 psi
6E2-24 ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE)
8) After checking fuel pressure, remove fuel pressure gauge
(1).
9) Remove fuel pressure gauge, hose and 3-way joint.
10) Connect fuel feed hose and clamp it securely.
11) With engine “OFF” and ignition switch “ON”, check for fuel
leaks.
Fuel pump
ON-VEHICLE INSPECTION
1) Remove filler cap and turn ON ignition switch (2). Then fuel
pump operating sound should be heard from fuel filler (1) for
about 3 seconds and stop. Be sure to reinstall fuel filler cap
after checking.
If above check result is not satisfactory, advance to “DIAG-
NOSTIC FLOW TABLE B-1” in Section 6-1
2) Fuel pressure should be felt at fuel return hose (1) for 3 sec-
onds after ignition switch ON.
If fuel pressure is not felt, advance to “DIAGNOSTIC FLOW
TABLE B-3” in Section 6-1. CAUTION:
As fuel feed line is still under high fuel pressure, make
sure to release fuel pressure according to following pro-
cedures.
Place fuel container under joint.
Cover joint with rag and loosen joint nut slowly to
release fuel pressure gradually.
CAUTION:
When fuel filler cap is removed in any procedure, work
must be done in a well-ventilated area, keep away from
any open flames and without smoking.