2004 DAEWOO NUBIRA low oil pressure

1.4L/1.6L DOHC ENGINE MECHANICAL 1C1 – 77
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
CYLINDER HEAD AND GASKET
The cylinder head is made of an aluminum alloy. The cylin-
der head uses cross–flow intake and exhaust ports. A
spark plug is located in the center of each combustion
chamber. The cylinder head houses the dual camshafts.
CRANKSHAFT
The crankshaft has eight integral weights which are cast
with it for balancing. Oil holes run through the center of the
crankshaft to supply oil to the connecting rods, the bear-
ings, the pistons, and the other components. The end
thrust load is taken by the thrust washers installed at the
center journal.
TIMING BELT
The timing belt coordinates the crankshaft and the dual
overhead camshafts and keeps them synchronized. The
timing belt also turns the water pump. The timing belt and
the pulleys are toothed so that there is no slippage be-
tween them. There are two idler pulleys. An automatic ten-
sioner pulley maintains the timing belt’s correct tension.
The timing belt is made of a tough reinforced rubber similar
to that used on the serpentine accessory drive belt. The
timing belt requires no lubrication.
OIL PUMP
The oil pump draws engine oil from the oil pan and feeds
it under pressure to the various parts of the engine. An oil
strainer is mounted before the inlet of the oil pump to re-
move impurities which could clog or damage the oil pump
or other engine components. When the drive gear rotates,
the driven gear rotates. This causes the space between
the gears to constantly open and narrow, pulling oil in from
the oil pan when the space opens and pumping the oil out
to the engine as it narrows.
At high engine speeds, the oil pump supplies a much high-
er amount of oil than is required for lubrication of the en-
gine. The oil pressure regulator prevents too much oil from
entering the engine lubrication passages. During normal
oil supply, a coil spring and valve keep the bypass closed,
directing all of the oil pumped to the engine. When the
amount of oil being pumped increases, the pressure be-
comes high enough to overcome the force of the spring.This opens the valve of the oil pressure regulator, allowing
the excess oil to flow through the valve and drain back to
the oil pan.
OIL PAN
The engine oil pan is mounted to the bottom of the cylinder
block. The engine oil pan houses the crankcase and is
made of cast metal.
Engine oil is pumped from the oil pan by the oil pump. After
it passes through the oil filter, it is fed through two paths
to lubricate the cylinder block and the cylinder head. In one
path, the oil is pumped through the oil passages in the
crankshaft to the connecting rods, then to the pistons and
the cylinders. It then drains back to the oil pan. In the sec-
ond path, the oil is pumped through the oil passages to the
camshaft. The oil passes through the internal passage-
ways in the camshafts to lubricate the valve assemblies
before draining back to the oil pan.
EXHAUST MANIFOLD
A single four–port, rear–takedown manifold is used with
this engine. The manifold is designed to direct escaping
exhaust gases out of the combustion chambers with a
minimum of back pressure. The oxygen sensor is
mounted to the exhaust manifold.
INTAKE MANIFOLD
The intake manifold has four independent long ports and
uses inertial supercharging to improve engine torque at
low and moderate speeds. The plenum is attached to the
intake manifold.
CAMSHAFTS
This engine is a dual overhead camshaft (DOHC) type,
which means there are two camshafts. One camshaft op-
erates the intake valves, and the other camshaft operates
the exhaust valves. The camshafts sit in journals on the
top of the engine in the cylinder head and are held in place
by camshaft caps. The camshaft journals of the cylinder
head are drilled to create oil passages. Engine oil travels
to the camshafts under pressure where it lubricates each
camshaft journal. The oil returns to the oil pan through
drain holes in the cylinder head. The camshaft lobes are
machined into the solid camshaft to open and close the in-
take and the exhaust valves precisely the correct amount
at the correct time. The camshaft lobes are oiled by splash
action from pressurized oil escaping from the camshaft
journals.

1.8L DOHC ENGINE MECHANICAL 1C2 – 75
DAEWOO V–121 BL4
GENERAL DESCRIPTION
AND SYSTEM OPERATION
CYLINDER HEAD AND GASKET
The cylinder head is made of an aluminum alloy. The cylin-
der head uses cross–flow intake and exhaust ports. A
spark plug is located in the center of each combustion
chamber. The cylinder head houses the dual camshafts.
CRANKSHAFT
The crankshaft has eight integral weights which are cast
with it for balancing. Oil holes run through the center of the
crankshaft to supply oil to the connecting rods, the bear-
ings, the pistons, and the other components. The end
thrust load is taken by the thrust washers installed at the
center journal.
TIMING BELT
The timing belt coordinates the crankshaft and the dual
overhead camshafts and keeps them synchronized. The
timing belt also turns the coolant pump. The timing belt
and the pulleys are toothed so that there is no slippage be-
tween them. There are two idler pulleys. An automatic ten-
sioner pulley maintains the timing belt’s correct 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.
OIL PUMP
The oil pump draws engine oil from the oil pan and feeds
it under pressure to the various parts of the engine. An oil
strainer is mounted before the inlet of the oil pump to re-
move impurities which could clog or damage the oil pump
or other engine components. When the crankshaft ro-
tates, the oil pump driven gear rotates. This causes the
space between the gears to constantly open and narrow,
pulling oil in from the oil pan when the space opens and
pumping the oil out to the engine as it narrows.
At high engine speeds, the oil pump supplies a much high-
er amount of oil than required for lubrication of the engine.
The oil pressure regulator prevents too much oil from en-
tering the engine lubrication passages. During normal oil
supply, a coil spring and valve keep the bypass closed, di-
recting all of the oil pumped to the engine. When the
amount of oil being pumped increases, the pressure be-
comes high enough to overcome the force of the spring.This opens the valve of the oil pressure regulator, allowing
the excess oil to flow through the valve and drain back to
the oil pan.
OIL PAN
The engine oil pan is mounted to the bottom of the cylinder
block. The engine oil pan houses the crankcase and is
made of cast aluminum.
Engine oil is pumped from the oil pan by the oil pump. After
it passes through the oil filter, it is fed through two paths
to lubricate the cylinder block and cylinder head. In one
path, the oil is pumped through oil passages in the crank-
shaft to the connecting rods, then to the pistons and cylin-
ders. It then drains back to the oil pan. In the second path,
the oil is pumped through passages to the camshaft. The
oil passes through the internal passageways in the cam-
shafts to lubricate the valve assemblies before draining
back to the oil pan.
EXHAUST MANIFOLD
A single four–port, rear–takedown manifold is used with
this engine. The manifold is designed to direct escaping
exhaust gases out of the combustion chambers with a
minimum of back pressure. The oxygen sensor is
mounted to the exhaust manifold.
INTAKE MANIFOLD
The intake manifold has four independent long ports and
utilizes an inertial supercharging effect to improve engine
torque at low and moderate speeds.
CAMSHAFTS
This engine is a dual overhead camshaft (DOHC) type,
which means there are two camshafts. One camshaft op-
erates the intake valves, and the other camshaft operates
the exhaust valves. The camshafts sit in journals on the
top of the engine (in the cylinder head) and are held in
place by camshaft caps. The camshaft journals of the cyl-
inder head are drilled for oil passages. Engine oil travels
to the camshafts under pressure where it lubricates each
camshaft journal. The oil returns to the oil pan through
drain holes in the cylinder head. The camshaft lobes are
machined into the solid camshaft to precisely open and
close the intake and the exhaust valves the correct
amount at the correct time. The camshaft lobes are oiled
by splash action from pressurized oil escaping from the
camshaft journals.

1D – 8IENGINE COOLING
DAEWOO V–121 BL4
MAINTENANCE AND REPAIR
ON–VEHICLE SERVICE
DRAINING AND REFILLING THE
COOLING SYSTEM
CAUTION : Do not remove the surge tank cap while
the engine and the radiator are hot. Scalding fluid and
steam may be blown out under pressure.
1. Place a pan below the vehicle to catch the draining
coolant.
2. Remove the surge tank cap.
3. Unplug the drain cock.
CAUTION : Dispose of the used coolant to a used
coolant holding tank to be picked up with the used oil
for disposal. Never pour the used coolant down the
drain. Ethylene glycol antifreeze is an extremely toxic
chemical. Disposing of it into the sewer system or the
ground water can contaminate the local environment.
4. Catch the escaping fluid in a drain pan.
5. Remove all sludge and dirt from inside the surge
tank. Refer to ”Surge Tank” in this section.
6. Plug the drain cock.
7. Add the clean water to the surge tank.
8. Fill the tank slowly so that the upper reservoir hose
remains above the water line. This allows the air
inside the cooling system to escape.
9. Start the engine.
10. Run the engine until the thermostat opens. You can
tell the thermostat is open when both radiator
hoses are hot to the touch.
11. Stop the engine.
12. Repeat Steps 1 through 9 until the drained water is
clear and free of coolant and rust.
Notice : Never use an antifreeze mixture more concen-
trated than 60 percent antifreeze to 40 percent water. The
solution freezing point increases above this concentration.
13. Fill the cooling system through the surge tank with
a mixture of ethylene glycol antifreeze and water.
The mixture must be at least 50 percent antifreeze,
but not more than 60 percent antifreeze.
14. Fill the surge tank to the specified MAX fill mark on
the outside of the tank.

1F – 2IENGINE CONTROLS
DAEWOO V–121 BL4
TROUBLE CODE DIAGNOSIS
(1.4L/1.6L DOHC) 1F–111. . . . . . . . . . . . . . . . . . . . . . . .
Clearing Trouble Codes 1F–111. . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Codes (1.4L/1.6L DOHC) 1F–111.
DTC P0107 Manifold Absolute Pressure Sensor
Low Voltage 1F–114. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0108 Manifold Absolute Pressure Sensor
High Voltage 1F–117. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0112 Intake Air Temperature Sensor Low
Voltage 1F–120. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0113 Intake Air Temperature Sensor High
Voltage 1F–122. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0117 Engine Coolant Temperature
Sensor Low Voltage 1F–125. . . . . . . . . . . . . . . . . . . .
DTC P0118 Engine Coolant Temperature
Sensor High Voltage 1F–128. . . . . . . . . . . . . . . . . . . .
DTC P0122 Throttle Position Sensor Low
Voltage 1F–131. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0123 Throttle Position Sensor High
Voltage 1F–134. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0131 Front Heated Oxygen Sensor Low
Voltage 1F–137. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0132 Front Heated Oxygen Sensor High
Voltage 1F–140. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0133 Front Heated Oxygen Sensor No
Activity 1F–142. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0135 Front Heated Oxygen Sensor Heater
Circuit Not Functioning 1F–145. . . . . . . . . . . . . . . . . .
DTC P0137 Rear Heated Oxygen Sensor Low
Voltage 1F–148. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0138 Rear Heated Oxygen Sensor High
Voltage 1F–151. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0140 Rear Heated Oxygen Sensor No
Activity 1F–153. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0141 Rear Heated Oxygen Sensor Heater
Malfunction 1F–156. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0171 Fuel Trim System Too Lean 1F–158. . . .
DTC P0172 Fuel Trim System Too Rich 1F–162. . . . .
DTC P0222 Main Throttle Idle Actuator (MTIA)
Low Voltage 1F–165. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0223 Main Throttle Idle Actuator (MTIA)
High Voltage 1F–168. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0261 Injector 1 Low Voltage 1F–171. . . . . . . . .
DTC P0262 Injector 1 High Voltage 1F–173. . . . . . . .
DTC P0264 Injector 2 Low Voltage 1F–175. . . . . . . . .
DTC P0265 Injector 2 High Voltage 1F–177. . . . . . . .
DTC P0267 Injector 3 Low Voltage 1F–179. . . . . . . . .
DTC P0268 Injector 3 High Voltage 1F–181. . . . . . . .
DTC P0270 Injector 4 Low Voltage 1F–183. . . . . . . . .
DTC P0271 Injector 4 High Voltage 1F–185. . . . . . . . DTC P0300 Multiple Cylinder Misfire(Catalyst
Damage) 1F–188. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0300 Multiple Cylinder Misfire(Increase
Emission) 1F–192. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0327 Knock Sensor Circuit Fault
(1.4L DOHC) 1F–195. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0327 Knock Sensor Circuit Fault
(1.6L DOHC) 1F–198. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0335 Magnetic Crankshaft Position
Sensor Electrical Error 1F–201. . . . . . . . . . . . . . . . . .
DTC P0336 58X Crankshaft Position Sensor
No Plausible Signal 1F–204. . . . . . . . . . . . . . . . . . . .
DTC P0337 58X Crankshaft Position Sensor
No Signal 1F–207. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0341 Camshaft Position Sensor
Rationality 1F–210. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0342 Camshaft Position Sensor Signal 1F–212
DTC P0351 Ignition Signal Coil A Fault 1F–214. . . . .
DTC P0352 Ignition Signal Coil B Fault 1F–216. . . . .
DTC P0400 Exhaust Gas Recirculation Out
Of Limit 1F–218. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0404 Exhaust Gas Recirculation
Opened 1F–221. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0405 EGR Pintle Position Sensor Low
Voltage 1F–224. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0406 EGR Pintle Position Sensor High
Voltage 1F–227. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0420 Catalyst Low Efficiency 1F–230. . . . . . . .
DTC P0444 EVAP Purge Control Circuit No
Signal 1F–232. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0445 EVAP Purge Control Circuit Fault 1F–235
DTC P0462 Fuel Level Sensor Low Voltage
(1.6L DOHC Only) 1F–238. . . . . . . . . . . . . . . . . . . . .
DTC P0463 Fuel Level Sensor High Voltage
(1.6L DOHC Only) 1F–241. . . . . . . . . . . . . . . . . . . . .
DTC P0480 Low Speed Cooling Fan Relay
Circuit Fault (1.4L DOHC) 1F–245. . . . . . . . . . . . . . .
DTC P0480 Low Speed Cooling Fan Relay
Circuit Fault (1.6L DOHC) 1F–248. . . . . . . . . . . . . . .
DTC P0481 High Speed Cooling Fan Relay
Circuit Fault (1.4L DOHC) 1F–251. . . . . . . . . . . . . . .
DTC P0481 High Speed Cooling Fan Relay
Circuit Fault (1.6L DOHC) 1F–254. . . . . . . . . . . . . . .
DTC P0501 Vehicle Speed No Signal
(M/T Only) 1F–257. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0510 Throttle Position Switch Circuit Fault
(1.4L DOHC) 1F–260. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0510 Throttle Position Switch Circuit
Fault (1.6L DOHC) 1F–262. . . . . . . . . . . . . . . . . . . . .
DTC P0532 A/C Pressure Sensor Low Voltage 1F–264
DTC P0533 A/C Pressure Sensor High
Voltage 1F–267. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1F – 28IENGINE CONTROLS
DAEWOO V–121 BL4
COMPONENT LOCATOR
COMPONENT LOCATOR (1.4L/1.6L DOHC)
Components on ECM Harness
11. Engine Control Module (ECM)
12. Data Link Connector (DLC)
13. Malfunction Indicator Lamp (MIL)
14. ECM/ABS Harness Ground
15. Fuse Panel (2)
ECM Controlled Devices
20. Exhaust Gas Recirculation (EGR) Valve
21. Fuel Injector (4)
22. Main Throttle Idle Actuator (MTIA)
23. Fuel Pump Relay
24. Cooling Fan Relays (High)
25. Cooling Fan Control Relay (A/C Only)
26. Electronic Ignition System Ignition Coil
27. Evaporative Emission (EVAP) Control Purge Sole-
noid
28. Main Relay
29. A/C Compressor Relay30. Cooling Fan Relays (Low)
Information Sensors
31. Manifold Absolute Pressure (MAP) Sensor
32. Front Heated Oxygen Sensor (HO2S1)
33. Variable Geometry Induction System (VGIS) Sole-
noid
34. Engine Coolant Temperature (ECT) Sensor
35. Intake Air Temperature (IAT) Sensor
36. Vehicle Speed Sensor (VSS)
38. Crankshaft Position (CKP) Sensor
39. Knock Sensor
40. Rear Heated Oxygen Sensor (HO2S2)
41. Camshaft Position (CMP) Sensor
Not PCM/ECM Connected
42. Evaporative Emission Canister (under vehicle, be-
hind right rear wheel)
43. Engine Oil Pressure Switch
44. Air Cleaner

ENGINE CONTROLS 1F – 29
DAEWOO V–121 BL4
COMPONENT LOCATOR (1.8L DOHC)
Components on ECM Harness
11. Engine Control Module (ECM)
12. Data Link Connector (DLC)
13. Malfunction Indicator Lamp (MIL)
14. ECM/ABS Harness Ground
15. Fuse Panel (2)
ECM Controlled Devices
20. Exhaust Gas Recirculation (EGR) Valve
21. Fuel Injector (4)
22. Idle Air Control (IAC) Valve
23. Fuel Pump Relay
24. Cooling Fan Relays (High)
25. Cooling Fan Control Relay (A/C Only)
26. Electronic Ignition System Ignition Coil
27. Evaporative Emission (EVAP) Control Purge Sole-
noid
28. Main Relay
29. A/C Compressor Relay30. Cooling Fan Relays (Low)
Information Sensors
31. Manifold Absolute Pressure (MAP) Sensor
32. Front Heated Oxygen Sensor (HO2S1)
33. Throttle Position (TP) Sensor
34. Engine Coolant Temperature (ECT) Sensor
35. Intake Air Temperature (IAT) Sensor
36. Vehicle Speed Sensor (VSS)
38. Crankshaft Position (CKP) Sensor
39. Knock Sensor
40. Rear Heated Oxygen Sensor (HO2S2)
41. Camshaft Position (CMP) Sensor
Not PCM/ECM Connected
42. Evaporative Emission Canister (under vehicle, be-
hind right rear wheel)
43. Engine Oil Pressure Switch
44. Air Cleaner

1F – 42IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
191. Measure the resistance between following ter-
minals:
S Terminal 1 and 2 of ignition coil.
S Terminal 2 and 1 of ignition coil.
Are the resistance within the value specified.
1. Remove the high tension cable.
2. Measure the resistance between second coil.
S Between 1 and 4
S Between 2 and 3
Are the resistance within the value specified.0.9 W
5.3 kWGo to Step 21Go to Step 20
20Replace the EI system ignition coil.
Is the repair complete?–Go to Step 2–
211. Check for any damages or poor connection in
ignition wires and repair as needed.
2. Connect the EI system ignition coil connector
and ECM connector.
3. Check for the presence of spark from all of the
ignition wires.
Is the spark present from all of the ignition wires?–Go to Step 2Go to Step 22
22Replace ECM.
Is the repair complete?–Go to Step 2–
231. Turn the ignition OFF.
2. Connect a fuel pressure gauge.
3. Crank the engine.
Is any fuel pressure present?–Go to Step 26Go to Step 24
241. Turn the ignition OFF.
2. Disconnect the electrical connector at the fuel
pump.
3. Connect a test light between the fuel pump ter-
minals 2 and 3.
4. Turn the ignition ON.
5. With the ignition ON, the test light should light
for the time specified.
Is the test light on?2 sec.Go to Step 25Go to 34
25Replace the fuel pump.
Is the repair complete?–Go to Step 2–
26Is the fuel pressure within the value specified?283–324 kPa
(41–47 psi)Go to Step 27Go to Step 29
27Check the fuel for contamination.
Is the fuel contaminated?–Go to Step 28Go to Step 41
281. Remove the contaminated fuel from the fuel
tank.
2. Clean the fuel tank as needed.
Is the repair complete?–Go to Step 2–
291. Check the fuel filter for restriction.
2. Inspect the fuel lines for kinks and restrictions.
3. Repair or replace as needed.
4. Measure the fuel pressure.
Is the fuel pressure within the value specified?283–324 kPa
(41–47 psi)Go to Step 2Go to Step 30

ENGINE CONTROLS 1F – 93
DAEWOO V–121 BL4
ENGINE COOLING FAN CIRCUIT CHECK – DUAL FAN
(1.4L/1.6L DOHC)
Circuit Description
The engine cooling fan circuit operates the main cooling
fan and the auxiliary cooling fan. The cooling fans are con-
trolled by the engine control module (ECM) based on in-
puts from the Engine Coolant Temperature (ECT) sensor
and the Air Conditioning Pressure (ACP) sensor. The
ECM controls the low speed cooling fan operation by inter-
nally grounding the ECM connector terminal 10. This ener-
gizes the low speed cooling fan relay and operates the
main cooling fan and the auxiliary cooling fan at low speed
as the cooling fans are connected in a series circuit. The
ECM controls the high speed cooling fan operation by in-
ternally grounding the ECM connector terminal 10 and the
ECM connector terminal 9 at the same time. This ener-
gizes the low speed cooling fan relay, the high speed cool-
ing fan relay, and the series/parallel cooling fan relay re-
sulting in high speed fan operation as the cooling fans are
now connected in a parallel circuit.
Diagnostic Aids
S If the owner complained of an overheating problem,
it must be determined if the complaint was due to
an actual boil over, or the engine coolant tempera-
ture gauge indicated overheating. If the engine is
overheating and the cooling fans are on, the cooling
system should be checked.
S If the engine fuse block fuses Ef11 become open
(blown) immediately after installation, inspect for a
short to ground in the wiring of the appropriate cir-
cuit. If the fuses become open (blown) when the
cooling fans are to be turned on by the ECM, sus-
pect a faulty cooling fan motor.
S The ECM will turn the cooling fans on at low speed
when the coolant temperature is 97°C (207°F). The
ECM will turn the cooling fans off when the coolant
temperature is 94°C(201°F).
S The ECM will turn the cooling fans on at high speed
when the coolant temperature is 101°C (214°F).
The ECM will change the cooling fans from high
speed to low speed when the coolant temperature
is 98°C (208°F).S The ECM will turn the cooling fans on at low speed
when the A/C system is on. The ECM will change
the cooling fans from low speed to high speed
when the high side A/C pressure is 1882 kPa (273
psi) then return to low speed when the high side
A/C pressure is 1448 kPa (210 psi). When the A/C
system is on, the ECM will change the cooling fans
from low to high speed when the coolant tempera-
ture reaches 117°C (244°F) then return to low
speed when the coolant temperature reaches
11 4°C (237°F).
S The cooling fan circuit can be checked quickly by
disconnecting the ECM connector 2 and grounding
the connector terminal 10. This should create low
speed cooling fan operation with the ignition ON. By
grounding the ECM connector terminals 10 and 9
and turning the ignition ON, high speed cooling fan
operation should be achieved.
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
4. This step, along with step 5, checks for the ability of
the ECM to operate the cooling fans.
8. This step, along with step 9, checks for the ability of
the ECM to operate the cooling fans in response to
A/C pressure readings.
16. After confirming battery voltage and the ECM sup-
plying a ground to the coil side of the cooling fan
relay A, by jumpering connector terminals 30 and
87 it will be determined if the relay is at fault or a
wiring problem is present.
31. This step checks for the presence of battery volt-
age to the main cooling fan when the A/C is on. If
battery voltage is present and the cooling fans are
not operating, the problem is in the ground side of
the cooling fan circuit.
37. By directly grounding the ECM connector terminals
10 and 9, the main and auxiliary cooling fans
should run at high speed.
Engine Cooling Fan Circuit Check – Dual Fan (1.4L/1.6L DOHC)
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) system
check.
Is the check completed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Check the engine fuse block fuse Ef11.
2. Replace the fuse as needed.
Is the fuse OK?–Go to Step 3Go to
”Diagnostic
Aids”