fuel pressure DAEWOO MATIZ 2003 Service Repair Manual

GENERAL ENGINE INFORMATION 1A–5
DAEWOO M-150 BL2
DIAGNOSTIC INFORMATION PROCEDURE
GENERAL DIAGNOSIS
 
 Condition
 
 Probable cause
 
 Correction
Hard Starting (WithMalfunction of
Faulty fuse.
Replace the fuse.
normal cranking)Ignition System
Faulty spark plug.
Clean, adjust the plug gap or
replace.

Electric leakage at the high
tension cable.
Replace the cable.

Poor connection of the high
tension cable or lead wires.
Replace the cable or wires.

Worn distributor cap or
accumulated carbon in the
distributor cap.
Replace or clean the
distributor cap.

Damaged distributor rotor or
cap.
Replace the rotor or the cap.

Improper ignition timing.
Adjust the ignition timing.

Faulty ignition coil.
Replace the ignition coil.
Malfunction of Fuel
Lock of fuel in the fuel tank.
Feed the fuel.
System
Dirty or clogged fuel filter.
Replace the filter.

Clogged fuel pipe.
Clean the fuel pipe.

Malfunction of the fuel pump.
Replace the fuel pump.

Malfunction of the fuel
injector.
Replace the injector.

The foreign material in the
fuel tank.
Clean the fuel tank.
Decline of
Compression
Poor tightening spark plug.
Tighten to the specified
torque.
Pressure
Cracked cylinder head
gasket.
Replace the gasket.

Inadequate the valve
clearance.
Adjust the clearance.

Leakage of the valve
clearance.
Repair the valve.

Interference of the valve
stem.
Replace the valve or the
valve guide.

Low elasticity or damage of
the valve spring.
Replace the valve spring.

Abnormal interference of
pistons and cylinders.
Replace the piston ring.

Excessive wear of pistons,
rings, or cylinders.
Replace the ring or the
piston and boring or replace
the cylinder.

1A–6 GENERAL ENGINE INFORMATION
DAEWOO M-150 BL2
GENERAL DIAGNOSIS (Cont’d)
 Condition Probable cause Correction
Hard Starting (WithOthers
Broken timing belt.
Replace the belt.
normal cranking)
Malfunction of Positive
Crankcase Ventilation (PCV)
valve.
Check and replace Positive
Crankcase Ventilation (PCV)
valve if needed.

Loosening, damage or
leakage of the vacuum hose.
Connect the hose correctly
or replace it.

Leakage of intake system.
Replace intake system.
Lack of Engine PowerDecline of
Compression
Pressure
Refer to “Page 1A–5”.
Refer to “Page 1A–5”.
Malfunction of
Improper ignition timing.
Adjust the ignition timing.
Ignition System
Faulty spark plug.
Adjust or replace the spark
plug.

Malfunction of the distributor.
Repair or replace the
distributor. Check the rotor.

Electric leakage or poor
connection of the high
tension cable.
Connect the cable correctly
or replace it.
Malfunction of
Clogged fuel pipe.
Clean the pipe.
Fuel System
Clogged or contaminated
fuel filter.
Replace the filter.
Others
Clogged exhaust system.
Check and repair the
system.

Clogged or contaminated air
cleaner element.
Clean or replace the air
cleaner element.

Leak of the intake manifold
gasket.
Replace the gasket.

Dragging brakes.
Repair or replace the
brakes.

Slipping clutch.
Adjust or replace the clutch.
Rough Engine IdlingDecline of
Compression
Pressure
Refer to “Page 1A–5”.
Refer to “Page 1A–5”.
Malfunction of
Clogged fuel pipe.
Clean the pipe.
Fuel System
Clogged or contaminated
fuel filter.
Replace the filter.

Malfunction of the fuel
pressure regulator.
Replace the regulator.
Malfunction of
Ignition System
Malfunction of the spark
plug.
Adjust or replace the spark
plug.

Electric leakage or poor
connection of the high
tension cable.
Connect the cable correctly
or replace it.

Worn distributor cap terminal
or accumulated carbon in
the distributor cap.
Replace or clean the
distributor cap.

GENERAL ENGINE INFORMATION 1A–7
DAEWOO M-150 BL2
GENERAL DIAGNOSIS (Cont’d)
 Condition Probable cause Correction
Rough Engine IdlingMalfunction of
Ignition System
Loosening or damage of the
distributor rotor or cap.
Replace the rotor or cap.

Poor ignition timing.
Adjust the ignition timing.

Malfunction of the ignition
coil.
Replace the ignition coil.
Others
Clogged or contaminated air
cleaner element.
Clean or replace the air
cleaner element.

Leak of the intake manifold
gasket.
Replace the gasket.

Malfunction of Positive
Crankcase Ventilation (PCV)
valve.
Check the valve or replace it
if needed.

Poor connection or damage
or leakage of the vacuum
hose.
Connect the hose correctly
or replace it.
Engine Hesitate (Upon
pressing accelerating
pedal, the engineDecline of
Compression
Pressure
Refer to “Page 1A–5”.
Refer to “Page 1A–5”.
makes delayed
response. ThisMalfunction of
Poor ignition timing.
Adjust the ignition timing.response. This
situation is remarkable
when cruising orIgnition System
Poor spark plug or poor
adjustment of the plug gap.
Replace the plug or adjust
the gap.
starting.)
Electric leakage or poor
connection of the high
tension cable.
Connect the cable correctly
or replace it.
Others
Malfunction of the air cleaner
system.
Clean or replace the air
cleaner system.

Leak of the intake manifold
gasket.
Replace the gasket.
Engine Surging
(Engine power makes
fluctuation in a fixedDecline of
Compression
Pressure
Refer to “Page 1A–5”.
Refer to “Page 1A–5”.
speed and speed
changes withoutMalfunction of
Clogged fuel pipe.
Clean the pipe.changes without
operating the
accelerating pedal.)Fuel System
Clogged or contaminated
fuel filter.
Replace the filter.

Malfunction of the fuel
pressure regulator.
Replace the fuel pressure
regulator.
Malfunction of
Ignition System
Malfunction of the spark
plug.
Adjust or replace the spark
plug.

Electric leakage or poor
connection of the high
tension cable.
Connect the cable correctly
or replace it.

Worn distributor cap terminal
or accumulated carbon in
the distributor cap.
Clean or replace the
distributor cap.

Loosening or damage of the
distributor rotor or the cap.
Replace the distributor rotor
or the cap.

Poor ignition timing.
Adjust the ignition timing.

1A–8 GENERAL ENGINE INFORMATION
DAEWOO M-150 BL2
GENERAL DIAGNOSIS (Cont’d)
 
 Condition
 
 Probable cause
 
 Correction
Engine Surging
(Engine power makes
fluctuation in a fixedOthers
Leak of the intake manifold
gasket.
Clean or replace the gasket.
speed and speed
changes without
operating the
accelerating pedal.)
Leakage of the vacuum hose.
Connect the hose correctly
or replace it.
Excessive Detonation
(According to theOverheated
Engine
Refer to “Overheat” in this
page.
Refer to “Overheat” in this
page.
opening range of
throttle valve,Malfunction of
Abnormal spark plug.
Replace the spark plug.
knocking sound of
metallic is made withIgnition System
Poor ignition timing.
Adjust the ignition timing.metallic is made with
abnormal explosion.)

Electric leakage or poor
connection of the high tension
cable.
Connect the cable correctly
or replace it.
Malfunction of
Fuel System
Clogged or contaminated fuel
filter and fuel pipe.
Clean or replace the fuel
filter and the fuel pipe.
Others
Leak of the intake manifold
gasket.
Replace the gasket.

Excessive carbon deposit due
to abnormal combustion.
Remove the carbon.
OverheatMalfunction of
Lack of coolant.
Refill coolant.
Cooling System
Malfunction of the thermostat.
Replace the thermostat.

Malfunction of the cooling fan.
Check or replace the cooling
fan.

Poor water pump
performance.
Replace the pump.

Clogged or leaky radiator.
Clean, repair or replace the
radiator.
Malfunction of
Lubrication
Poor engine oil.
Replace engine oil with the
specified one.
System
Blocking oil filter or strainer.
Clean or replace the oil filter
or the strainer.

Lack of engine oil.
Refill oil.

Poor oil pump performance.
Replace or repair the pump.

Leakage of oil.
Repair.
Other
Damaged cylinder head
gasket.
Replace the gasket.
Poor Fuel
ConsumptionDecline of
Compression
Pressure
Refer to “Page 1A–5”.
Refer to “Page 1A–5”.
Malfunction of
Fuel System
Leakage of the fuel tank or
the fuel pipe.
Repair or replace the fuel
tank or the fuel pipe.

GENERAL ENGINE INFORMATION 1A–9
DAEWOO M-150 BL2
GENERAL DIAGNOSIS (Cont’d)
 Condition Probable cause Correction
Poor FuelMalfunction of
Improper ignition timing.
Adjust the ignition timing.
ConsumptionIgnition System
Abnormal spark plug
(Excessive carbon deposit,
inadequate gap, burnt
electrode).
Replace the plug.

Electric leakage or poor
connection of the high
tension cable.
Connect the cable normally
or replace it.
Malfunction of
Cooling System
Malfunction of the
thermostat.
Replace the thermostat.
Others
Improperly installed valve.
Repair or replace the valve.

Slipping clutch.
Repair or replace the clutch.

Low pressure of tires.
Adjust the pressure of tires.
ExcessiveLeakage of
Loosened oil drain plug.
Tighten the plug.
Consumption of
Engine OilEngine Oil
Loosened oil pan bolt.
Tighten the bolt.Engine Oil

Loosened oil filter.
Tighten the filter.

Loosened oil pressure
switch.
Tighten the switch.

Leakage of camshaft front oil
seal.
Replace the seal.

Leakage of crankshaft front
oil seal.
Replace the seal.

Leakage at the cylinder head
cover gasket.
Replace the gasket.

Damage of the cylinder head
gasket.
Replace the gasket.
Oil Mixing in
Combustion
Stuck piston ring.
Remove carbon and replace
the ring.
Chamber
Worn piston or cylinder.
Replace the piston or the
cylinder.

Worn piston ring or ring
groove.
Replace the piston or ring.

Inadequate position of the
piston ring cutting part.
Adjust the position.

Abrasion or damage of the
valve system.
Replace the valve system.
Low Oil PressureMalfunction of
Lubrication
Inadequate oil viscosity.
Replace with the specified
one.
System
Loosening of the oil pressure
switch.
Tighten the switch.

Lack of engine oil.
Refill oil.

Blocking oil strainer.
Clean the strainer.

1A–14 GENERAL ENGINE INFORMATION
DAEWOO M-150 BL2
SPECIFICATIONS
GENERAL SPECIFICATIONS
 Application Description
  Maximum Speed 144 km/h (90 mph)
 Vehicle Capacity Gradeability 0.420 tan θ
 
Vehicle Capacity
 Minimum Turning Radius 4.5 m (14.8 ft)
  Bore × Stroke 68.5 × 72.0 mm (2.70 × 2.83 inch)
  Displacement 796 cm3 (48.6 in3)
  Compression Ratio 9.3 : 1
  Maximum Power 37.5 KW (6,000 rpm)
 
Engine Information
 Maximum Torque 68.6 Nm (50.59 lb-ft) (at 4,600 rpm)
Ignition Timing (Ignition Sequence)5 BTDC (1–3–2) / 10 BTDC (1–3–2)   
Air Conditioning System (ON)
 
1,000 ± 50 rpm  Idle Speed Air Conditioning System (OFF) 950 rpm  Engine Overhead Cam L–3 
 
 
 Ignition Type
 
 Direct Ignition System (DIS) /
High Energy Ignition (HEI)
  Distributor Optical Sensor Type
  Starter SD 80
   Unleaded BPR5EY–11, RN9YC4, WR8DCX
  Spark–Plug Leaded BPR5EY, RN9YC, WR8DC
  Fuel Injection Type MPI
  Fuel Pump Electric Motor Pump
Engine Part TypeFuel FilterCartridge Engine Part Type 
Lubricating Type
 
Forced Feed Type  Oil Pump Rotary Pump Type  Cooling Type Forced Water Circulation  Radiator Cross – Flow  Water Pump Centrifugal  Thermostat Pellet Type
  Air Cleaner Element Non Woven Fablic
  Muffler Catalytic Converter, Closed Circuit
  Battery MF
Engine PartEngine OilSJ Grade
SAE 5W30, SAE 10W30, SAE 15W40
CapacityRefrigerantFour Seasons   
Engine Disassembly
 
3.0 L (3.17 qt)   Oil Change (Including filter) 2.7 L (2.85 qt)  Engine Oil Oil Change (Not including filter) 2.5 L (2.64 qt)   Oil Level Gauge 1 L (1.06 qt) (MIN to MAX)  Coolant 3.8 L (4.02 qt) Engine Information Battery 12V–35 AH, 246 CCA
 Engine Information  

Generator

65 A
  Starter 0.8 kW
   Output Capacity 90 – 133 Lph
  Fuel Pump Output Pressure 380 kPa (55.1 Psi)
  Fuel Tank Capacity 35 L (9.2 gal), 38 L (10 gal)

DAEWOO M-150 BL2
SECTION 1F
ENGINE CONTROLS
CAUTION: Disconnect the negative battery cable before removing or installing any electrical unit or when a
tool or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cable
will help prevent personal injury and damage to the vehicle. The ignition must also be in LOCK unless
otherwise noted.
TABLE OF CONTENTS
Description and Operation 1F-4. . . . . . . . . . . . . . . . . .
Ignition System Operation 1F-4. . . . . . . . . . . . . . . . . .
Electronic Ignition System Ignition Coil 1F-4. . . . . . .
Crankshaft Position Sensor 1F-4. . . . . . . . . . . . . . . . .
Camshaft Position Sensor 1F-4. . . . . . . . . . . . . . . . . .
Idle Air System Operation 1F-4. . . . . . . . . . . . . . . . . .
Fuel Control System Operation 1F-4. . . . . . . . . . . . . .
Evaporative Emission Control System
Operation 1F-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Controlled Charcoal Canister 1F-5. . . . . . . . . . . . . . . .
Positive Crankcase Ventilation Control System
Operation 1F-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Coolant Temperature Sensor 1F-6. . . . . . . . .
Throttle Position Sensor 1F-6. . . . . . . . . . . . . . . . . . . .
Catalyst Monitor Oxygen Sensors 1F-6. . . . . . . . . . .
Electric Exhaust Gas Recirculation Valve 1F-6. . . . .
Intake Air Temperature Sensor 1F-7. . . . . . . . . . . . . .
Idle Air Control Valve 1F-7. . . . . . . . . . . . . . . . . . . . . .
Manifold Absolute Pressure Sensor 1F-7. . . . . . . . . .
Engine Control Module 1F-8. . . . . . . . . . . . . . . . . . . . .
Fuel Injector 1F-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Cutoff Switch (Inertia Switch) 1F-8. . . . . . . . . . .
Knock Sensor 1F-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Variable Reluctance (VR) Sensor 1F-8. . . . . . . . . . . .
Octane Number Connector 1F-8. . . . . . . . . . . . . . . . .
Strategy-Based Diagnostics 1F-9. . . . . . . . . . . . . . . .
EOBD Serviceability Issues 1F-9. . . . . . . . . . . . . . . . .
Serial Data Communications 1F-10. . . . . . . . . . . . . . .
Euro On-Board Diagnostic (EOBD) 1F-10. . . . . . . . .
Comprehensive Component Monitor Diagnostic
Operation 1F-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Common EOBD Terms 1F-11. . . . . . . . . . . . . . . . . . . .
DTC Types 1F-13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reading Diagnostic Trouble Codes 1F-13. . . . . . . . .
Primary System-Based Diagnostics 1F-15. . . . . . . . Diagnostic Information and Procedures 1F-17. . . .
System Diagnosis 1F-17. . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Aids 1F-17. . . . . . . . . . . . . . . . . . . . . . . . . .
Idle Learn Procedure 1F-17. . . . . . . . . . . . . . . . . . . . .
Euro On-Board Diagnostic (EOBD) System
Check 1F-18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ECM Output Diagnosis 1F-20. . . . . . . . . . . . . . . . . . . .
Multiple ECM Information Sensor DTCs Set 1F-21. .
Engine Cranks But Will Not Run 1F-25. . . . . . . . . . . .
No Malfunction Indicator Lamp 1F-30. . . . . . . . . . . . .
Malfunction Indicator Lamp On Steady 1F-32. . . . . .
Fuel System Diagnosis 1F-34. . . . . . . . . . . . . . . . . . . .
Fuel Pump Relay Circuit Check 1F-36. . . . . . . . . . . .
Main Relay Circuit Check 1F-38. . . . . . . . . . . . . . . . . .
Manifold Absolute Pressure Check 1F-40. . . . . . . . . .
Idle Air Control System Check 1F-42. . . . . . . . . . . . .
Ignition System Check 1F-45. . . . . . . . . . . . . . . . . . . .
Engine Cooling Fan Circuit Check 1F-48. . . . . . . . . .
Data Link Connector Diagnosis 1F-52. . . . . . . . . . . . .
Fuel Injector Balance Test 1F-54. . . . . . . . . . . . . . . . .
Diagnostic Trouble Code Diagnosis 1F-55. . . . . . . .
Clearing Trouble Codes 1F-55. . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Codes 1F-55. . . . . . . . . . . . . . . . .
DTC P0107 Manifold Absolute Pressure Sensor
Low Voltage 1F-58. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0108 Manifold Pressure Sensor High
Voltage 1F-62. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0112 Intake Air Temperature Sensor Low
Voltage 1F-66. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0113 Intake Air Temperature Sensor High
Voltage 1F-68. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0117 Engine Coolant Temperature Sensor
Low Voltage 1F-72. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0118 Engine Coolant Temperature Sensor
High Voltage 1F-74. . . . . . . . . . . . . . . . . . . . . . . . . . .

ENGINE CONTROLS 1F–3
DAEWOO M-150 BL2
DTC P1628 Immobilizer No Successful
Communication 1F-270. . . . . . . . . . . . . . . . . . . . . . .
DTC P1629 Immovilizer Wrong Computation 1F-272
DTC P0656 Fuel Level Gauge Circuit Fault 1F-274.
DTC P1660 Malfunction Indicator Lamp (MIL)
High Voltage 1F-276. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1661 Malfunction Indicator Lamp (MIL)
Low Voltage 1F-278. . . . . . . . . . . . . . . . . . . . . . . . . .
Symptom Diagnosis 1F-280. . . . . . . . . . . . . . . . . . . . . .
Important Preliminary Checks 1F-280. . . . . . . . . . . . .
Intermittent 1F-281. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hard Start 1F-283. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Surges or Chuggles 1F-286. . . . . . . . . . . . . . . . . . . . .
Lack of Power, Sluggishness or Sponginess 1F-288
Detonation/Spark Knock 1F-290. . . . . . . . . . . . . . . . . .
Hesitation, Sag, Stumble 1F-292. . . . . . . . . . . . . . . . .
Cuts Out, Misses 1F-294. . . . . . . . . . . . . . . . . . . . . . . .
Poor Fuel Economy 1F-296. . . . . . . . . . . . . . . . . . . . . .
Rough, Unstable, or Incorrect Idle, Stalling 1F-297. .
Excessive Exhaust Emissions or Odors 1F-300. . . .
Dieseling, Run-on 1F-302. . . . . . . . . . . . . . . . . . . . . . .
Backfire 1F-303. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance and Repair 1F-304. . . . . . . . . . . . . . . . . .
On-Vehicle Service 1F–304 . . . . . . . . . . . . . . . . . . . . . . .
Fuel Pump 1F–304 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Pressure Regulator 1F-305. . . . . . . . . . . . . . . . .
Fuel Filter 1F-306. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Tank 1F-307. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Rail and Injectors 1F-308. . . . . . . . . . . . . . . . . . .
Evaporator Emission Canister 1F-309. . . . . . . . . . . . . Evaporator Emission Canister Purge
Solenoid 1F-310. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manifold Absolute Pressure (MAP) Sensor 1F-310. .
Throttle Body 1F-311. . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Coolant Temperature (ECT) Sensor 1F-312.
Intake Air Temperature (ECT) Sensor 1F-313. . . . . .
Oxygen Sensor (O2S 1) 1F-314. . . . . . . . . . . . . . . . . .
Heated Oxygen Sensor (HO2S 2) 1F-314. . . . . . . . .
Electric Exhaust Gas Recirculation (EEGR)
Valve 1F-315. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Knock Sensor 1F-315. . . . . . . . . . . . . . . . . . . . . . . . . . .
Electronic Ignition (EI) System Ignition Coil 1F-316.
Crankshaft Position (CKP) Sensor 1F-316. . . . . . . .
Camshaft Position (CMP) Sensor 1F-317. . . . . . . . . .
Engine Control Module (ECM) 1F-317. . . . . . . . . . . . .
Specifications 1F-319. . . . . . . . . . . . . . . . . . . . . . . . . . .
Fastener Tightening Specification 1F-319. . . . . . . . . .
Special Tools 1F-319. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Tools Table 1F-319. . . . . . . . . . . . . . . . . . . . . .
Schematic and Routing Diagrams 1F-320. . . . . . . . .
ECM Wiring Diagram
(Sirius D3 – 1 of 5) 1F-320. . . . . . . . . . . . . . . . . . . .
ECM Wiring Diagram
(Sirius D3 – 2 of 5) 1F-321. . . . . . . . . . . . . . . . . . . .
ECM Wiring Diagram
(Sirius D3 – 3 of 5) 1F-322. . . . . . . . . . . . . . . . . . . .
ECM Wiring Diagram
(Sirius D3 – 4 of 5) 1F-323. . . . . . . . . . . . . . . . . . . .
ECM Wiring Diagram
(Sirius D3 – 5 of 5) 1F-324. . . . . . . . . . . . . . . . . . . .

1F–4 ENGINE CONTROLS
DAEWOO M-150 BL2
DESCRIPTION AND OPERATION
IGNITION SYSTEM OPERATION
This ignition system does not use a conventional distrib-
utor and coil. It uses a crankshaft position sensor input
to the Engine Control Module (ECM). The ECM then de-
termines Electronic Spark Timing (EST) and triggers the
electronic ignition system ignition coil.
This type of distributorless ignition system uses a “waste
spark’’ method of spark distribution. Each cylinder is in-
dividural with coil per cylinder.
These systems use the EST signal from the ECM to
control the EST. The ECM uses the following informa-
tion:

Engine load (manifold pressure or vacuum).

Atmospheric (barometric) pressure.

Engine temperature.

Intake air temperature.

Crankshaft position.

Engine speed (rpm).
ELECTRONIC IGNITION SYSTEM
IGNITION COIL
The Electronic Ignition (EI) system ignition coil is
mounted near on the cylinder head.
A terminals of the EI system ignition coil provides the
spark for each spark plug. The EI system ignition coil is
not serviceable and must be replaced as an assembly.
CRANKSHAFT POSITION SENSOR
This Electronic Ignition (EI) system uses a magnetic
crankshaft position sensor. This sensor protrudes
through its mount to within approximately 1.3 mm (0.05
inch) of the crankshaft reluctor. The reluctor is a special
wheel attached to the crankshaft with 58 slots machined
into it, 57 of which are equally spaced in 6-degree inter-
vals. The last slot is wider and serves to generate a
“sync pulse.” As the crankshaft rotates, the slots in the
reluctor change the magnetic field of the sensor, creat-
ing an induced voltage pulse. The longer pulse of the
58th slot identifies a specific orientation of the crank-
shaft and allows the Engine Control Module (ECM) to
determine the crankshaft orientation at all times. The
ECM uses this information to generate timed ignition
and injection pulses that it sends to the ignition coils and
to the fuel injectors.
CAMSHAFT POSITION SENSOR
The Camshaft Position (CMP) sensor sends a CMP sig-
nal to the Engine Control Module (ECM). The ECM uses
this signal as a “sync pulse” to trigger the injectors in the
proper sequence. The ECM uses the CMP signal to indi-
cate the position of the #1 piston during its power stroke.
This allows the ECM to calculate true sequential fuel in-jection mode of operation. If the ECM detects an incor-
rect CMP signal while the engine is running, Diagnostic
Trouble Code (DTC) P0341 will set. If the CMP signal is
lost while the engine is running, the fuel injection system
will shift to a calculated sequential fuel injection mode
based on the last fuel injection pulse, and the engine will
continue to run. As long as the fault is present, the en-
gine can be restarted. It will run in the calculated se-
quential mode with a 1-in-6 chance of the injector
sequence being correct.
IDLE AIR SYSTEM OPERATION
The idle air system operation is controlled by the base
idle setting of the throttle body and the Idle Air Control
(IAC) valve.
The Engine Control Module (ECM) uses the IAC valve to
set the idle speed dependent on conditions. The ECM
uses information from various inputs, such as coolant
temperature, manifold vacuum, etc., for the effective
control of the idle speed.
FUEL CONTROL SYSTEM
OPERATION
The function of the fuel metering system is to deliver the
correct amount of fuel to the engine under all operating
conditions. The fuel is delivered to the engine by the in-
dividual fuel injectors mounted into the intake manifold
near each cylinder.
The main fuel control sensors are the Manifold Absolute
Pressure (MAP) sensor, the oxygen sensor (O2S), and
the heated oxygen sensor (HO2S).
The MAP sensor measures or senses the intake man-
ifold vacuum. Under high fuel demands, the MAP sensor
reads a low vacuum condition, such as wide open
throttle. The Engine Control Module (ECM) uses this in-
formation to enrich the mixture, thus increasing the fuel
injector on-time, to provide the correct amount of fuel.
When decelerating, the vacuum increases. This vacuum
change is sensed by the MAP sensor and read by the
ECM, which then decreases the fuel injector on-time
due to the low fuel demand conditions.
The O2S is located in the exhaust manifold. The HO2S
is located in the exhaust pipe. The oxygen sensors indi-
cate to the ECM the amount of oxygen in the exhaust
gas, and the ECM changes the air/fuel ratio to the en-
gine by controlling the fuel injectors. The best air/fuel ra-
tio to minimize exhaust emissions is 14.7:1, which
allows the catalytic converter to operate most efficiently.
Because of the constant measuring and adjusting of the
air/fuel ratio, the fuel injection system is called a “closed
loop” system.
The ECM uses voltage inputs from several sensors to
determine how much fuel to provide to the engine. The

ENGINE CONTROLS 1F–5
DAEWOO M-150 BL2
fuel is delivered under one of several conditions, called
“modes.’’
Starting Mode
When the ignition is turned ON, the ECM turns the fuel
pump relay on for 2 seconds. The fuel pump then builds
fuel pressure. The ECM also checks the Engine Coolant
Temperature (ECT) sensor and the Throttle Position
(TP) sensor and determines the proper air/fuel ratio for
starting the engine. The ECM controls the amount of
fuel delivered in the starting mode by changing how long
the fuel injector is turned on and off. This is done by
“pulsing’’ the fuel injectors for very short times.
Run Mode
The run mode has two conditions called “open loop’’ and
“closed loop.’’
Open Loop
When the engine is first started and it is above 400 rpm,
the system goes into “open loop’’ operation. In “open
loop,’’ the ECM ignores the signal from the O2S and cal-
culates the air/fuel ratio based on inputs from the ECT
sensor and the MAP sensor. The ECM stays in ”open
loop” until the following conditions are met:

The O2S has a varying voltage output, showing that it
is hot enough to operate properly.

The ECT sensor is above a specified temperature.

A specific amount of time has elapsed after starting
the engine.
Closed Loop
The specific values for the above conditions vary with
different engines and are stored in the Electronically
Erasable Programmable Read-Only Memory (EE-
PROM). When these conditions are met, the system
goes into “closed loop” operation. In “closed loop,” the
ECM calculates the air/fuel ratio (fuel injector on-time)
based on the signals from the oxygen sensors. This al-
lows the air/fuel ratio to stay very close to 14.7 to 1.
Acceleration Mode
The ECM responds to rapid changes in throttle position
and airflow and provides extra fuel.
Deceleration Mode
The ECM responds to changes in throttle position and
airflow and reduces the amount of fuel. When decelera-
tion is very fast, the ECM can cut off fuel completely for
short periods of time.
Battery Voltage Correction Mode
When battery voltage is low, the ECM can compensate
for a weak spark delivered by the ignition module by us-
ing the following methods:

Increasing the fuel injector pulse width.

Increasing the idle speed rpm.

Increasing the ignition dwell time.
Fuel Cut-Off Mode
No fuel is delivered by the fuel injectors when the ignition
is off. This prevents dieseling or engine run-on. Also, the
fuel is not delivered if there are no reference pulses re-
ceived from the CKP sensor. This prevents flooding.
EVAPORATIVE EMISSION CONTROL
SYSTEM OPERATION
The basic Evaporative Emission (EVAP) control system
used is the charcoal canister storage method. This
method transfers fuel vapor from the fuel tank to an acti-
vated carbon (charcoal) storage canister which holds
the vapors when the vehicle is not operating. When the
engine is running, the fuel vapor is purged from the car-
bon element by intake airflow and consumed in the nor-
mal combustion process.
Gasoline vapors from the fuel tank flow into the tube la-
beled TANK. These vapors are absorbed into the car-
bon. The canister is purged by Engine Control Module
(ECM) when the engine has been running for a specified
amount of time. Air is drawn into the canister and mixed
with the vapor. This mixture is then drawn into the intake
manifold.
The ECM supplies a ground to energize the controlled
charcoal canister purge solenoid valve. This valve is
Pulse Width Modulated (PWM) or turned on and off sev-
eral times a second. The controlled charcoal canister
purge PWM duty cycle varies according to operating
conditions determined by mass airflow, fuel trim, and in-
take air temperature.
Poor idle, stalling, and poor driveability can be caused
by the following conditions:

An inoperative controlled canister purge valve.

A damaged canister.

Hoses that are split, cracked, or not connected to the
proper tubes.
CONTROLLED CHARCOAL
CANISTER
The controlled charcoal canister is an emission control
device containing activated charcoal granules. The con-
trolled charcoal canister is used to store fuel vapors from
the fuel tank. Once certain conditions are met, the En-
gine Control Module (ECM) activates the controlled
charcoal canister purge solenoid, allowing the fuel va-
pors to be drawn into the engine cylinders and burned.
POSITIVE CRANKCASE
VENTILATION CONTROL SYSTEM
OPERATION
A Positive Crankcase Ventilation (PCV) control system
is used to provide complete use of the crankcase va-