ABS DAEWOO MATIZ 2003 Service Repair Manual

GENERAL ENGINE INFORMATION 1A–3
DAEWOO M-150 BL2
COMPONENT LOCATOR
ENGINE COMPARTMENT (TYPICAL)
(Left–Hand Drive Shown, Right–Hand Drive Similar)
D102A401
1 Power Steering Oil Reservoir
2 Coolant Reservoir
3 Canister
4 Canister Solenoid
5 Manifold Absolute Pressure (MAP) Sensor
6 Intake Manifold
7 Ignition Coil
8 Idle Air Control (IAC) Valve
9 Throttle Position (TP) Sensor
10 Throttle Body
11 Brake Fluid Reservoir
12 Wiper Motor13 Battery
14 Fuse Box
15 Air Cleaner Housing
16 Resonator
17 PCV Hose
18 Distributor
19 Exhaust Manifold
20 Snorkel
21 Engine
22 Washer Fluid Reservoir
23 Oil Level Gauge
24 Oil Filler Cap

1A–4 GENERAL ENGINE INFORMATION
DAEWOO M-150 BL2
ENGINE COMPARTMENT (EURO III)
(Left–Hand Drive Shown, Right–Hand Drive Similar)
MAA1A010
1 Power Steering Oil Reservoir
2 Coolant Reservoir
3 Canister Purge Solenoid
4 Manifold Absolute Pressure (MAP) Sensor
5 Intake Manifold
6 Throttle Position (TP) Sensor
7 Throttle Body
8 Idle Air Control (IAC) Valve
9 Brake Fluid Reservoir
10 Wiper Motor11 Battery
12 Fuse Box
13 Air Cleaner Housing
14 Resonator
15 Electronic Ignition System Ignition Coil
16 Exhaust Manifold
17 Snorkel
18 Engine
20 Washer Fluid Reservoir
19 Oil Level Gauge
21 Oil Filler Cap

1B –4 SOHC ENGINE MECANICAL
DAEWOO M-150 BL2
TIMING BELT AND PULLEY
The timing belt connects the camshaft timing pulley (w)
and the crankshaft timing pulley (x). The timing belt
coordinates the crankshaft and the camshaft and keeps
them synchronized. The timing belt also turns the cool-
ant pump (y). The timing belt and the pulleys are toothed
so that there is no slippage between them. There is a
tension pulley (z) that maintains the correct timing belt
tension. The timing belt is made of a tough reinforced
rubber similar to that used on the serpentine drive belt.
The timing belt requires no lubrication.
D102B006
ENGINE MOUNT
This is to absorb or reduce the engine vibration and im-
pact from the wheeled road. Engine mount is attached to
the engine–front side, the engine-right side and the en-
gine-rear side and one transaxle mount is attached to
the transaxle side.
D102B007
D102B008

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. . . . . . . . . . . . . . . . . . . . . . . . . . .

1F – 2 ENGINE CONTROLS
DAEWOO M-150 BL2
DTC P0122 Throttle Position Sensor Low
Voltage 1F-76. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0123 Throttle Position Sensor High
Voltage 1F-80. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0131 Oxygen Sensor Low Voltage 1F-84. . . .
DTC P0132 Oxygen Sensor High Voltage 1F-88. . . .
DTC P0133 Oxygen Sensor No Activity 1F-90. . . . .
DTC P0137 Heated Oxygen Sensor Low
Voltage 1F-94. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0138 Heated Oxygen Sensor High
Voltage 1F-98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0140 Heated Oxygen Sensor
No Activity 1F-100. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0141 Heated Oxygen Sensor
Heater Malfunction 1F-104. . . . . . . . . . . . . . . . . . . .
DTC P0171 Fuel Trim System Too Lean 1F-106. . . .
DTC P0172 Fuel Trim System Too Rich 1F-109. . . .
DTC P1230 Fuel Pump Relay Low Voltage 1F-114.
DTC P1231 Fuel Pump Relay High Voltage 1F-118.
DTC P0261 Injector 1 Low Voltage 1F-122. . . . . . . .
DTC P0262 Injector 1 High Voltage 1F-124. . . . . . . .
DTC P0264 Injector 2 Low Voltage 1F-126. . . . . . . .
DTC P0265 Injector 2 High Voltage 1F-128. . . . . . . .
DTC P0267 Injector 3 Low Voltage 1F-130. . . . . . . .
DTC P0268 Injector 3 High Voltage 1F-132. . . . . . . .
DTC P0300 Multiple Cylinder Misfire 1F-135. . . . . . .
DTC P0300 Multiple Cylinder Misfire 1F-139. . . . . . .
DTC P1320 Crankshaft Segment Period
Segment adaptation At Limit 1F-142. . . . . . . . . . . .
DTC P1321 Crankshaft Segment Period
Tooth Error 1F-144. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0327 Knock Sensor Circuit Fault 1F-146. . . .
DTC P0335 Magnetic Crankshaft Position
Sensor Electrical Error 1F-150. . . . . . . . . . . . . . . . .
DTC P0336 58X Crankshaft Position Sensor
No Plausible Signal 1F-152. . . . . . . . . . . . . . . . . . . .
DTC P0337 58X Crankshaft Position Sensor
No Signal 1F-154. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0341 Camshaft Position Sensor
Rationality 1F-156. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0342 Camshaft Position Sensor
No Signal 1F-158. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0351 Ignition Signal Coil A Fault 1F-160. . . . .
DTC P0352 Ignition Signal Coil B Fault 1F-162. . . . .
DTC P0353 Ignition Signal Coil C Fault 1F-164. . . . .
DTC P1382 Rough Road Data
Invalid (Non ABS) 1F-166. . . . . . . . . . . . . . . . . . . . .
DTC P1382 Rough Road Data Invalid (ABS) 1F-170
DTC P1385 Rough Road Sensor Circuit Fault
(Non ABS) 1F-174. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1385 Rough Road Sensor Circuit Fault
(ABS) 1F-178. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DTC P0400 Exhaust Gas Recirculation
Out Of Limit 1F-182. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1402 Exhaust Gas Recirculation
Blocked 1F-186. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1403 Exhaust Gas Recirculation
Valve Failure 1F-188. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0404 Exhaust Gas Recirculation
Opened 1F-192. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1404 Exhaust Gas Recirculation
Closed 1F-196. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0405 EEGR Pintle Position Sensor
Low Voltage 1F-200. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0406 EEGR Pintle Position Sensor
High Voltage 1F-204. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0420 Catalyst Low Efficiency 1F-208. . . . . . . .
DTC P0444 EVAP Purge Control Circuit
No Signal 1F-210. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0445 EVAP Purge Control Fault 1F-214. . . . .
DTC P0462 Fuel Level Sensor Low Voltage 1F-218.
DTC P0463 Fuel Level Sensor High Voltage 1F-222
DTC P0480 Low Speed Cooling Fan Relay
Circuit Fauit (Without A/C) 1F-226. . . . . . . . . . . . . .
DTC P0480 Low Speed Cooling Fan Relay
Circuit Fauit (With A/C) 1F-230. . . . . . . . . . . . . . . . .
DTC P0481 High Speed Cooling Fan Relay
Circuit Fauit (Without A/C) 1F-234. . . . . . . . . . . . . .
DTC P0481 High Speed Cooling Fan Relay
Circuit Fauit (With A/C) 1F-238. . . . . . . . . . . . . . . . .
DTC P0501 Vehicle Speed No Signal
(M/T Only) 1F-242. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1505 Idle Air Control Valve (IACV)
Error 1F-246. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1535 Evaporator Temperature Sensor
High Voltage 1F-250. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1536 Evaporator Temperature Sensor
Low Voltage 1F-252. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1537 A/C Compressor Relay High
Voltage 1F-254. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1538 A/C Compressor Relay Low
Voltage 1F-256. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0562 System Voltage (Engine Side)
Too Low 1F-258. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0563 System Voltage (Engine Side)
Too High 1F-260. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0601 Engine Control Module Chechsum
Error 1F-262. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0604 Engine Control Module Internal/
External RAM Error 1F-263. . . . . . . . . . . . . . . . . . . .
DTC P0605 Engin Control Module NMVY
Write Error 1F-264. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1610 Main Relay High Voltage 1F-266. . . . . .
DTC P1611 Main Relay Low Voltage 1F-268. . . . . . .

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-

ENGINE CONTROLS 1F–7
DAEWOO M-150 BL2
manifold to decrease combustion temperature. The
amount of exhaust gas recirculated is controlled by vari-
ations in vacuum and exhaust back pressure. If too
much exhaust gas enters, combustion will not take
place. For this reason, very little exhaust gas is allowed
to pass through the valve, especially at idle.
The EEGR valve is usually open under the following
conditions:

Warm engine operation.

Above idle speed.
Results of Incorrect Operation
Too much EEGR flow tends to weaken combustion,
causing the engine to run roughly or to stop. With too
much EEGR flow at idle, cruise, or cold operation, any of
the following conditions may occur:

The engine stops after a cold start.

The engine stops at idle after deceleration.

The vehicle surges during cruise.

Rough idle.
If the EEGR valve stays open all the time, the engine
may not idle. Too little or no EEGR flow allows combus-
tion temperatures to get too high during acceleration
and load conditions. This could cause the following con-
ditions:

Spark knock (detonation)

Engine overheating

Emission test failure
INTAKE AIR TEMPERATURE
SENSOR
The Intake Air Temperature (IAT) sensor is a thermistor,
a resistor which changes value based on the tempera-
ture of the air entering the engine. Low temperature pro-
duces a high resistance (100 kohms at –40C [–40F]),
while high temperature causes a low resistance (70
ohms at 130C [266F]).
The Engine Control Module (ECM) provides 5 volts to
the IAT sensor through a resistor in the ECM and mea-
sures the change in voltage to determine the IAT. The
voltage will be high when the manifold air is cold and low
when the air is hot. The ECM knows the intake IAT by
measuring the voltage.
The IAT sensor is also used to control spark timing when
the manifold air is cold.
A failure in the IAT sensor circuit sets a diagnostic
trouble code P0112 or P0113.
IDLE AIR CONTROL VALVE
Notice: Do not attempt to remove the protective cap
and readjust the stop screw. Misadjustment may result
in damage to the Idle Air Control (IAC) valve or to the
throttle body.The IAC valve is mounted on the throttle body where it
controls the engine idle speed under the command of
the Engine Control Module (ECM). The ECM sends volt-
age pulses to the IAC valve motor windings, causing the
IAC valve pintle to move in or out a given distance (a
step or count) for each pulse. The pintle movement con-
trols the airflow around the throttle valves which, in turn,
control the engine idle speed.
The desired idle speeds for all engine operating condi-
tions are programmed into the calibration of the ECM.
These programmed engine speeds are based on the
coolant temperature, the park/neutral position switch
status, the vehicle speed, the battery voltage, and the
A/C system pressure, if equipped.
The ECM “learns” the proper IAC valve positions to
achieve warm, stabilized idle speeds (rpm) desired for
the various conditions (park/neutral or drive, A/C on or
off, if equipped). This information is stored in ECM ”keep
alive” memories (information is retained after the ignition
is turned off). All other IAC valve positioning is calcu-
lated based on these memory values. As a result, en-
gine variations due to wear and variations in the
minimum throttle valve position (within limits) do not af-
fect engine idle speeds. This system provides correct
idle control under all conditions. This also means that
disconnecting power to the ECM can result in incorrect
idle control or the necessity to partially press the accel-
erator when starting until the ECM relearns idle control.
Engine idle speed is a function of total airflow into the
engine based on the IAC valve pintle position, the
throttle valve opening, and the calibrated vacuum loss
through accessories. The minimum throttle valve posi-
tion is set at the factory with a stop screw. This setting
allows enough airflow by the throttle valve to cause the
IAC valve pintle to be positioned a calibrated number of
steps (counts) from the seat during “controlled” idle op-
eration. The minimum throttle valve position setting on
this engine should not be considered the “minimum idle
speed,” as on other fuel injected engines. The throttle
stop screw is covered with a plug at the factory following
adjustment.
If the IAC valve is suspected as being the cause of im-
proper idle speed, refer to “Idle Air Control System
Check” in this section.
MANIFOLD ABSOLUTE PRESSURE
SENSOR
The Manifold Absolute Pressure (MAP) sensor mea-
sures the changes in the intake manifold pressure which
result from engine load and speed changes and con-
verts these to a voltage output.
A closed throttle on engine coast down produces a rela-
tively low MAP output. MAP is the opposite of vacuum.
When manifold pressure is high, vacuum is low. The
MAP sensor is also used to measure barometric pres-
sure. This is performed as part of MAP sensor calcula-

1F–8 ENGINE CONTROLS
DAEWOO M-150 BL2
tions. With the ignition ON and the engine not running,
the Engine Control Module (ECM) will read the manifold
pressure as barometric pressure and adjust the air/fuel
ratio accordingly. This compensation for altitude allows
the system to maintain driving performance while hold-
ing emissions low. The barometric function will update
periodically during steady driving or under a wide open
throttle condition. In the case of a fault in the barometric
portion of the MAP sensor, the ECM will set to the de-
fault value.
A failure in the MAP sensor circuit sets a diagnostic
trouble codes P0107, P0108 or P0106.
ENGINE CONTROL MODULE
The Engine Control Module (ECM), is the control center
of the fuel injection system. It constantly looks at the in-
formation from various sensors and controls the sys-
tems that affect the vehicle’s performance. The ECM
also performs the diagnostic functions of the system. It
can recognize operational problems, alert the driver
through the Malfunction Indicator Lamp (MIL), and store
diagnostic trouble code(s) which identify the problem
areas to aid the technician in making repairs.
There are no serviceable parts in the ECM. The calibra-
tions are stored in the ECM in the Programmable Read
Only Memory (PROM).
The ECM supplies either 5 or 12 volts to power the sen-
sors or switches. This is done through resistance in the
ECM which are so high in value that a test light will not
come on when connected to the circuit. In some cases,
even an ordinary shop voltmeter will not give an accu-
rate reading because its resistance is too low. You must
use a digital voltmeter with a 10 megohm input imped-
ance to get accurate voltage readings. The ECM con-
trols output circuits such as the fuel injectors, the Idle Air
Control (IAC) valve, the A/C clutch relay, etc., by control-
ling the ground circuit through transistors or a device
called a “quad-driver.”
FUEL INJECTOR
The Multi-port Fuel Injection (MFI) assembly is a sole-
noid-operated device controlled by the Engine Control
Module (ECM) that meters pressurized fuel to a single
engine cylinder. The ECM energizes the fuel injector or
solenoid to a normally closed ball or pintle valve. This al-
lows fuel to flow into the top of the injector, past the ball
or pintle valve, and through a recessed flow director
plate at the injector outlet.
The director plate has six machined holes that control
the fuel flow, generating a conical spray pattern of finely
atomized fuel at the injector tip. Fuel from the tip is di-
rected at the intake valve, causing it to become further
atomized and vaporized before entering the combustion
chamber. A fuel injector which is stuck partially open
would cause a loss of fuel pressure after the engine is
shut down. Also, an extended crank time would be no-
ticed on some engines. Dieseling could also occur be-cause some fuel could be delivered to the engine after
the ignition is turned off.
FUEL CUT-OFF SWITCH
The fuel cutoff switch is a safety device. In the event of a
collision or a sudden impact, it automatically cuts off the
fuel supply and activates the door lock relay. After the
switch has been activated, it must be reset in order to
restart the engine. Reset the fuel cutoff switch by press-
ing the rubber top of the switch. The switch is located
near the right side of the passenger’s seat.
KNOCK SENSOR
The knock sensor detects abnormal knocking in the en-
gine. The sensor is mounted in the engine block near the
cylinders. The sensor produces an AC output voltage
which increases with the severity of the knock. This sig-
nal is sent to the Engine Control Module (ECM). The
ECM then adjusts the ignition timing to reduce the spark
knock.
VARIABLE RELUCTANCE (VR)
SENSOR
The variable reluctance sensor is commonly refered to
as an “inductive” sensor.
The VR wheel speed sensor consists of a sensing unit
fixed to the left side front macpherson strut, for non-ABS
vehicle.
The ECM uses the rough road information to enable or
disable the misfire diagnostic. The misfire diagnostic
can be greatly affected by crankshaft speed variations
caused by driving on rough road surfaces. The VR sen-
sor generates rough road information by producing a
signal which is proportional to the movement of a small
metal bar inside the sensor.
If a fault occurs which causes the ECM to not receive
rough road information between 30 and 70 km/h (1.8
and 43.5 mph), Diagnostic Trouble Code (DTC) P1391
will set.
OCTANE NUMBER CONNECTOR
The octane number connector is a jumper harness that
signal to the engine control module (ECM) the octane
rating of the fuel.
The connector is located on the next to the ECM. There
are two different octane number connector settings
available. The vehicle is shipped from the factory with a
label attached to the jumper harness to indicate the oc-
tane rating setting of the ECM. The ECM will alter fuel
delivery and spark timing based on the octane number
setting. The following table shows which terminal to
jump on the octane number connector in order to
achieve the correct fuel octane rating. Terminal 2 is
ground on the octane number connector. The find the