heater DAEWOO LACETTI 2004 Service User Guide

ENGINE CONTROLS 1F – 3
DAEWOO V–121 BL4
DTC P0562 System Voltage(Engine Side) Too
Low 1F–270. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0563 System Voltage(Engine Side) Too
High 1F–272. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0601 Engine Control Module Checksum
Error 1F–274. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0604 Engine Control Module Internal/External
RAM Error 1F–275. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0605 Engine Control Module INMVY Write
Error 1F–276. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0656 Fuel Level Gauge Circuit Fault 1F–277. .
DTC P1181 Variable Intake Manifold Solenoid
Low Voltage 1F–279. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1182 Variable Intake Manifold Solenoid
High Voltage 1F–281. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1230 Fuel Pump Relay Low Voltage
(1.4L DOHC) 1F–283. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1230 Fuel Pump Relay Low Voltage
(1.6L DOHC) 1F–286. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1231 Fuel Pump Relay High Voltage
(1.4L DOHC) 1F–289. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1231 Fuel Pump Relay High Voltage
(1.6L DOHC) 1F–292. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1320 Crankshaft Segment Period
Segment Adaptation At Limit 1F–295. . . . . . . . . . . .
DTC P1321 Crankshaft Segment Period Tooth
Error 1F–297. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1382 Rough Road Data Invalid
(NON ABS) 1F–299. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1382 Rough Road Data Invalid (ABS) 1F–302
DTC P1385 Rough Road Sensor Circuit Fault
(NON ABS) 1F–305. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1402 Exhaust Gas Recirculation
Blocked 1F–308. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1403 Exhaust Gas Recirculation Valve
Failure 1F–310. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1404 Exhaust Gas Recirculation Closed1F–313
DTC P1511 Idle Charge Actuator Circuit Fault 1F–316
DTC P1512 Idle Charge Actuator Mechanical
Error 1F–319. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1513 Idle Charge Actuator Functional
Error 1F–321. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1537 A/C Compressor Relay High
Voltage 1F–324. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1538 A/C Compressor Relay Low
Voltage 1F–326. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1610 Main Relay High Voltage
(1.4L DOCH) 1F–328. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1610 Main Relay High Voltage
(1.6L DOHC) 1F–330. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1611 Main Relay Low Voltage
(1.4L DOHC) 1F–332. . . . . . . . . . . . . . . . . . . . . . . . . . DTC P1611 Main Relay Low Voltage
(1.6L DOHC) 1F–334. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1628 Immobilizer No Successful
Communication 1F–336. . . . . . . . . . . . . . . . . . . . . . . .
DTC P1629 Immobilizer Wrong Computation 1F–338
DTC P1660 Malfunction Indicator Lamp (MIL)
High Voltage 1F–340. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1661 Malfunction Indicator Lamp (MIL)
Low Voltage 1F–342. . . . . . . . . . . . . . . . . . . . . . . . . . .
TROUBLE CODE DIAGNOSIS (1.8L DOHC) 1F–344.
Clearing Trouble Codes 1F–344. . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Codes (1.8L DOHC) 1F–344. . . .
DTC P0106 Manifold Absolute Pressure
Rationality 1F–347. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0107 Manifold Absolut Pressure Low
Voltage 1F–349. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0108 Manifold Absolut Pressure High
Voltage 1F–352. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0112 Intake Air Temperature Low
Voltage 1F–355. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0113 Intake Air Temperature High
Voltage 1F–358. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0117 Engine Coolant Temperature Low
Voltage 1F–361. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0118 Engine Coolant Temperature High
Voltage 1F–363. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0122 Throttle Position Sensor Low
Voltage 1F–366. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0123 Throttle Position Sensor High
Voltage 1F–369. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0131 Front Heated Oxygen Sensor
(HO2S1) Low Voltage 1F–372. . . . . . . . . . . . . . . . . .
DTC P0132 Front Heated Oxygen Sensor
(HO2S1) High Voltage 1F–375. . . . . . . . . . . . . . . . . .
DTC P0133 Front Heated Oxygen Sensor
(HO2S1) Slow Response 1F–378. . . . . . . . . . . . . . .
DTC P0134 Front Heated Oxygen Sensor
(HO2S1) No Activity or Open 1F–382. . . . . . . . . . . .
DTC P0135 Front Heated Oxygen Sensor
(HO2S1) Heater Circuit Not Functioning 1F–385. . .
DTC P0137 Rear Heated Oxygen Sensor
(HO2S2) Low Voltage 1F–388. . . . . . . . . . . . . . . . . .
DTC P0138 Rear Heated Oxygen Sensor
(HO2S2) High Voltage 1F–391. . . . . . . . . . . . . . . . . .
DTC P0140 Rear Heated Oxygen Sensor
(HO2S2) No Activity or Open 1F–394. . . . . . . . . . . .
DTC P0141 Rear Heated Oxygen Sensor
(HO2S2) Heater Circuit Not Functioning 1F–397. . .
DTC P0171 Fuel Trim System Too Lean 1F–400. . . .
DTC P0172 Fuel Trim System Too Rich 1F–404. . . . .
DTC P0201 Injector 1 Circuit Fault 1F–408. . . . . . . . .
DTC P0202 Injector 2 Circuit Fault 1F–411. . . . . . . . .

ENGINE CONTROLS 1F – 111
DAEWOO V–121 BL4
TROUBLE CODE DIAGNOSIS
(1.4L/1.6L DOHC)
CLEARING TROUBLE CODES
Notice : To prevent Engine Control Module (ECM) dam-
age, the key must be OFF when disconnecting or recon-
necting the power to the ECM (for example battery cable,
ECM pigtail connector, ECM fuse, jumper cables,
etc.).When the ECM sets a Diagnostic Trouble Code
(DTC), the Malfunction Indicator Lamp (MIL) lamp will be
turned on only for type A, B and E but a DTC will be stored
in the ECM’s memory for all types of DTC. If the problemis intermittent, the MIL will go out after 10 seconds if the
fault is no longer present. The DTC will stay in the ECM’s
memory until cleared by scan tool. Removing battery volt-
age for 10 seconds will clear some stored DTCs.
DTCs should be cleared after repairs have been com-
pleted. Some diagnostic tables will tell you to clear the
codes before using the chart. This allows the ECM to set
the DTC while going through the chart, which will help to
find the cause of the problem more quickly.
DIAGNOSTIC TROUBLE CODES (1.4L/1.6L DOHC)
DTCFunctionError
TypeIlluminate MIL
P0107Manifold Absolute Pressure Sensor Low VoltageAYES
P0108Manifold Absolute Pressure Sensor High VoltageAYES
P0112Intake Air Temperature Sensor Low VoltageEYES
P0113Intake Air Temperature Sensor High VoltageEYES
P0117Engine Coolant Temperature Sensor Low VoltageAYES
P0118Engine Coolant Temperature Sensor High VoltageAYES
P0122Throttle Position Sensor Low VoltageAYES
P0123Throttle Position Sensor High VoltageAYES
P0131Front Heated Oxygen Sensor Low VoltageAYES
P0132Front Heated Oxygen Sensor High VoltageAYES
P0133Front Heated Oxygen Sensor No ActivityEYES
P0135Front Heated Oxygen Sensor Heater Circuit Not FunctioningEYES
P0137Rear Heated Oxygen Sensor Low VoltageEYES
P0138Rear Heated Oxygen Sensor High VoltageEYES
P0140Rear Heated Oxygen Sensor No ActivityEYES
P0141Rear Heated Oxygen Sensor Heater MalfuctionEYES
P0171Fuel Trim System Too LeanEYES
P0172Fuel Trim System Too RichEYES
P0222Main Throttle Idle Actuactor (MTIA) Low VoltageAYES
P0223Main Throttle Idle Actuactor (MTIA) High VoltageAYES
P0261Injector 1 Low VoltageAYES
P0262Injector 1 High VoltageAYES
P0264Injector 2 Low VoltageAYES
P0265Injector 2 High VoltageAYES
P0267Injector 3 Low VoltageAYES
P0268Injector 3 High VoltageAYES
P0270Injector 4 Low VoltageAYES
P0271Injector 4 High VoltageAYES
P0300Multiple Cylinder Misfire (Catalyst Damage)ABLINKING

ENGINE CONTROLS 1F – 145
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0135
FRONT HEATED OXYGEN SENSOR HEATER CIRCUIT
NOT FUNCTIONING
Circuit Description
Heated oxygen sensors (HO2S) are used for fuel control
and post catalyst monitoring. Each HO2S compares the
oxygen content of the surrounding air with the oxygen con-
tent in the exhaust stream. The HO2S must reach operat-
ing temperature to provide an accurate voltage signal. A
heating element inside the HO2S minmizes the time re-
quired for the sensor to reach operating temperature. Volt-
age is provided to the heater by the ignition 1 voltage cir-
cuit through a fuse. With the engine running, ground is
provided to the heater by the HO2S heater low control cir-
cuit, through a low side driver within the engine control
module (ECM). The ECM monitors the current flow
through the heater for diagnosis.
If the ECM detects that the HO2S heater current is above
or blelow a specified range, DTC P0135 seats.
Conditions for Setting the DTC
S DTCs P0106, P0117, P0118, P1017 are not set.
S Engine run time is greater than 30 seconds.
S Filtered O2 heater current is less than 0.1 amps.
Action Taken When the DTC SetsS The Malfunction Indicator Lamp (MIL) will illuminate
after three consecutive trip with a fail.
S The ECM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Freeze Frame and Failure Records
buffers.
S A history Diagnostic Trouble Code (DTC) is stored.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after three consecutive ignition
cycles in which the diagnostic runs without a fault.
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
Diagnostic Aids
An intermittent may be caused by rubbed through wire in-
sulation or a wire contacting the exhaust.
Check for poor connection or damaged harness – inspect
harness connectors for the following conditions:
S Improper mating
S Broken locks
S Improperly formed
S Damaged terminals
S Poor terminal–to–wire connection

1F – 146IENGINE CONTROLS
DAEWOO V–121 BL4
S Damaged harness
Test Description
Number(s) below refer to the step number(s) on the Diag-
nostic Table.
1. The On–Board Diagnostic (EOBD) System Check
prompts the technician to complete some basic
checks and store the freeze frame and failure re-
cords data on the scan tool if applicable. This
creates an electronic copy of the data taken when
the malfunction occurred. The information is then
stored on the scan tool for later reference.
2. This step determines if DTC P0135 is the result of
a hard failure or an intermittent condition. With the
ignition ON, engine OFF, the HO2S1 voltage dis-played on the scan tool should change within sever-
al minutes toward 0 or 1 volt, indicating that the
heater is working properly.
3. Probing terminal 4 of the HO2S1 connector verifies
if voltage is available to the HO2S1 heater.
4. If voltage is available at the connector, than it be-
comes a good voltage source to check for a ground
at terminal 3.
5. Determines if voltage is not available at the HO2S1
due to an open in the HO2S1 fuse or open ignition
feed circuit. If the fuse is open, determine if it was
due to a short in the ignition feed circuit before re-
placing the fuse.
DTC P0135 – Front Heated Oxygen Sensor Heater Circuit Not
Functioning
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
2Notice : If the engine has just been operating, allow
the engine to cool for about one–half hour before
proceeding.
1. Turn the ignition switch ON, with the engine
OFF.
2. Install a scan tool.
Does the Front Heated Oxygen Sensor (HO2S1)
voltage gradually change toward the specified volt-
age?0 v or 1 vGo to Step 13Go to Step 3
31. Disconnect the HO2S1 electrical connector.
2. With a test light connected to ground, probe
the ignition feed circuit, terminal 2 of the con-
nector.
Does the test light illuminate?–Go to Step 4Go to Step 5
4Connect a test light between the ignition feed and
ground circuits, terminal 2 and 3 of the connector.
Does the test light illuminate?–Go to Step 6Go to Step 7
5Inspect the fuse in the engine fuse block.
Is the fuse open?–Go to Step 8Go to Step 9
6Check the connections terminal 2 and 1 at the
HO2S2 connector and repair as necessary.
Is a repair necessary?–Go to Step 13Go to Step 10
7Check the connections terminal 4 at the HO2S1 con-
nector and repair as necessary.
Is a repair necessary?–Go to Step 13Go to Step 11
81. Check for a short to ground in the HO2S1 igni-
tion feed circuit and repair as necessary?
2. Replace open fuse.
Is the action complete?–Go to Step 13–

1F – 154IENGINE CONTROLS
DAEWOO V–121 BL4
Diagnostic Aids
Normal scan tool voltage varies between 0.15 to 8.5mV
while in Closed Loop. If DTC P0140 is intermittent, refer
to ”Intermittents” in this section.
DTC P0140 – Rear Heated Oxygen Sensor No Activity
StepActionValue(s)YesNo
1Perform an Euro On–Board Diagnostic (EOBD)
System Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Run the engine to above the specified operat-
ing temperature.
2. Install a scan tool.
3. Operate the engine above the specified rpm for
2 minuets.
Does the scan tool the indicate Closed Loop?80°C(176°F)
1,200rpmGo to Step 3Go to Step 4
31. Turn the Turn the ignition switch to ON.
2. Review the Freeze Frame data and note the
parameters.
3. Operate the vehicle within the freeze frame
conditions and Conditions for Setting the DTC
as noted?
Does the scan tool the indicate Closed Loop?–Go to Step 12Go to Step 4
4Disconnect the Heated O2 sensor connector and
jumper the Heated O2 sensor low circuit, terminal 3
to ground.
Is the HO2 voltage below the specified value and
does the scan tool indicate the heated oxygen sen-
sor heater voltage within the specified value?0.5VGo to Step 5Go to Step 6
5Check the Heated O2 sensor connector for malfunc-
tion terminals or poor connection and repair as nec-
essary.
Is repair necessary?–Go to Step 12Go to Step 9
61. Turn the ignition switch to On.
2. Remove the jumper wire.
3. Using a digital voltmeter(DVM), measure the
voltage between the Heated O2 sensor signal
circuit, terminal 4 to ground.
Does the Heated O2 sensor voltage measure above
the specified value?0.6VGo to Step 10Go to Step 9
7Does the Heated O2 sensor voltage measure below
the specified value?0.3VGo to Step 11Go to Step 8
8Check the Heated O2 sensor ground circuit, termi-
nal 3 for an open or poor connection and repair as
necessary.
Is repair necessary?–Go to Step 12Go to Step 8
9Check the Heated O2 sensor signal circuit, terminal
4 for an open or poor connection and repair as nec-
essary.
Is repair necessary?–Go to Step 12Go to Step 8

1F – 156IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0141
REAR HEATED OXYGEN SENSOR HEATER
MALFUNCTION
Circuit Description
The engine control module (ECM) supplies a voltage of
about 450mm volts between the ECM terminals 14 and 16.
The oxygen (O2) sensor varies the voltage within a range
of about 1volt if the exhaust is rich, down to about 100mm
volts if the exhaust is lean. The O2 sensor is like an open
circuit and produces no voltage when it is below
360°C(600°F). An open O2 sensor circuit or a cold O2
sensor causes ”open loop” operation.
Conditions for Setting the DTC
S The heated O2 sensor heater resistance is less
than 0 W or greater than 160 W. (1.4L DOHC)
S The heated O2 sensor heater resistance is less
than 10 W or greater than 30 W. (1.6L DOHC)
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illuminate
after three consecutive trip with a fail.
S The ECM will record operating conditions at the
time the diagnostic fail. This information will be
stored in the Freeze Frame and Failure Records
buffers.
S A history DTC is stored.S The coolant fan turns ON.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after four consecutive ignition
cycles in which the diagnostic runs without a fault.
S A history DTC will clear after 40 consecutive warm
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for 10 sec-
onds.
Diagnostic Aids
S Normal scan tool voltage varies between 0.1volts
and 0.9 volts while in closed loop.
S Inspect the oxygen (O2) sensor wire. The O2 sen-
sor may be positioned incorrectly and contacting
the exhaust manifold.
S Check for an intermittent ground in the wire be-
tween the O2 sensor and the engine control mod-
ule.
S Perform an injector 2alance test to determine if a
restricted fuel injector may be causing the lean con-
dition.
S Vacuum of crankcase leaks will cause a lean run-
ning condition.

ENGINE CONTROLS 1F – 157
DAEWOO V–121 BL4
S An exhaust manifold gasket leak of a cracked ex-
haust manifold may cause outside air to be pulled
into the exhaust and past the sensor.
DTC P0141 – Rear Heated Oxygen Sensor Heater Malfunction
StepActionValue(s)YesNo
1Perform an Euro On–Board Diagnostic (EOBD)
System Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Turn the ignition switch to LOCK.
2. Disconnect the Heated O2 sensor connector
and engine control module (ECM) connector.
3. Check the Heated O2 sensor heater wire be-
tween the Heated O2 sensor connector termi-
nal 3 and ECM connector terminal 16 for an
open or short to ground.
Is the problem found?–Go to Step 3Go to Step 4
31. Repair the wire of the connector terminal as
needed.
2. Clear the DTCs from the ECM.
3. Road tests the vehicle.
4. Perform the diagnostic system check.
Is the repair complete?–System OK–
41. Turn the ignition switch to LOCK.
2. Replace the Heated O2 sensor.
3. Road tests the vehicle.
4. Perform the diagnostic system check.
Is the replacement complete?–Go to Step 6–
5Check if any additional DTCs are set.
Are any DTCs displaced that have not been diag-
nosed?–Go to applica-
ble DTC tableSystem OK

1F – 230IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0420
CATALYST LOW EFFICIENCY
Circuit Description
In order to control exhaust emissions of Hydrocarbons
(HC), Carbon Monoxide (CO) and Nitrogen Oxide (NOx),
a Three–Way Catalytic Converter (TWC) is used. The cat-
alyst within the converter promotes a chemical reaction
which oxidizes the HC and CO present in the exhaust gas,
converting them into harmless water vapor and carbon
dioxide, it also reduces NOx, converting it into nitrogen.
The catalytic converter also has the ability to store oxygen.
The Engine Control Module (ECM) has the capability to
monitor this process using a Heated Oxygen Sensor
(HO2S) located in the exhaust stream past the TWC. The
HO2S produces an output signal which indicates the oxy-
gen storage capacity of the catalyst; this in turn indicates
the catalyst’s ability to convert exhaust emissions effec-
tively. The ECM monitors the catalyst efficiency by first al-
lowing the catalyst to heat up, waiting for a stabilization pe-
riod while the engine is idling, and then adding and
removing fuel while monitoring the reaction of the HO2S.
When the catalyst is functioning properly, the HO2S re-
sponse to the extra fuel is slow compared to the Oxygen
Sensor (O2S). When the HO2S response is close to that
of the O2S, the Oxygen storage capability or efficiency of
the catalyst is considered to be bad, and the Malfunction
Indicator Lamp (MIL) will illuminate.
Conditions for Setting the DTC
S Closed loop stoichiometry.
S Engine Coolant Temperature (ECT) is more than
75°C (167°F) . (1.4L DOHC)
S Engine Coolant Temperature (ECT) is more than
70°C (158°F) . (1.6L DOHC)
S Engine speed between 1,766rpm and 2,368rpm.
(1.4L DOHC)
S Engine speed between 1,760rpm and 2,530rpm.
(1.6L DOHC)
S Vehicle speed is between 47km/h (29.2mph) and
80km/h (49.7mph). (1.4L DOHC)
S Vehicle speed is between 60km/h (37.3mph) and
76km/h (47.2mph). (1.6L DOHC)
S The manifold absolute pressure is greater than 70
kpa. (1.4L DOHC)S The manifold absolute pressure is greater than 76
kpa. (1.6L DOHC)
S Activity of the heated oxygen sensor excited by
lambda controller stimuli higher than a threshold.
S DTC(s) P0107, P0108, P0117, P0118, P0122,
P0123, P0131, P0132, P0133, P0137, P0138,
P0140, P0141, P0171, P0172, P0300, P0336,
P0337, P0341, P0342, P0351, P0352, P0404,
P0405, P0405 and P0562 are not sets.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illuminate
after three consecutive trip with a fail.
S The ECM will record operating conditions at the
time the diagnostic fail. This information will be
stored in the Freeze Frame and Failure Records
buffers.
S A history DTC is stored.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after four consecutive ignition
cycles in which the diagnostic runs without a fault.
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
The catalyst test may abort due to a change in the engine
load. Do not change the engine load (i.e. A/C, coolant fan,
heater motor) while a catalyst test is in progress.
An intermittent problem may be caused by a poor connec-
tion, rubbed–through wire insulation, or a wire that is bro-
ken inside the insulation.
Any circuitry, that is suspected as causing the intermittent
complaint, should be thoroughly checked for the following
conditions:
S Backed–out terminals
S Improper mating
S Broken locks
S Improperly formed
S Damaged terminals
S Poor terminal–to–wire connection.

1F – 344IENGINE CONTROLS
DAEWOO V–121 BL4
TROUBLE CODE DIAGNOSIS (1.8L DOHC)
CLEARING TROUBLE CODES
Notice : To prevent Engine Control Module (ECM) dam-
age, the key must be OFF when disconnecting or recon-
necting the power to the ECM (for example battery cable,
ECM pigtail connector, ECM fuse, jumper cables, etc.).
When the ECM sets a Diagnostic Trouble Code (DTC), the
Malfunction Indicator Lamp (MIL) lamp will be turned on
only for type A, B and E but a DTC will be stored in the
ECM’s memory for all types of DTC. If the problem is inter-mittent, the MIL will go out after 10 seconds if the fault is
no longer present. The DTC will stay in the ECM’s memory
until cleared by scan tool. Removing battery voltage for 10
seconds will clear some stored DTCs.
DTCs should be cleared after repairs have been com-
pleted. Some diagnostic tables will tell you to clear the
codes before using the chart. This allows the ECM to set
the DTC while going through the chart, which will help to
find the cause of the problem more quickly.
DIAGNOSTIC TROUBLE CODES (1.8L DOHC)
DTCDescriptionTypeIlluminate MIL
P0106Manifold Absolute Pressure RationalityEYe s
P0107Manifold Absolute Pressure Low VoltageAYe s
P0108Manifold Absolute Pressure High VoltageAYe s
P0112Intake Air Temperature Low VoltageEYe s
P0113Intake Air Temperature High VoltageEYe s
P0117Engine Coolant Temperature Low VoltageAYe s
P0118Engine Coolant Temperature High VoltageAYe s
P0122Throttle Position Sensor Low VoltageAYe s
P0123Throttle Position Sensor High VoltageAYe s
P0131Front Heated Oxygen Sensor (HO2S1) Low VoltageAYe s
P0132Front Heated Oxygen Sensor (HO2S1) High VoltageAYe s
P0133Front Heated Oxygen Sensor (HO2S1) Slow ResponseEYe s
P0134Front Heated Oxygen Sensor (HO2S1) No Activity or OpenAYe s
P0135Front Heated Oxygen Sensor (HO2S1) Heater Circuit Not FunctioningEYe s
P0137Rear Heated Oxygen Sensor (HO2S2) Low VoltageEYe s
P0138Rear Heated Oxygen Sensor (HO2S2) High VoltageEYe s
P0140Rear Heated Oxygen Sensor (HO2S2) No Activity or OpenEYe s
P0141Rear Heated Oxygen Sensor (HO2S2) Heater Circuit Not FunctioningEYe s
P0171Fuel Trim System Too LeanBYe s
P0172Fuel Trim System Too RichBYe s
P0201Injector 1 Circuit FaultAYe s
P0202Injector 2 Circuit FaultAYe s
P0203Injector 3 Circuit FaultAYe s
P0204Injector 4 Circuit FaultAYe s
P0300Multiple Cylinder Misfire DetectedBYe s
P0301Cylinder 1 MisfireAYe s
P0302Cylinder 2 MisfireAYe s
P0303Cylinder 3 MisfireAYe s
P0304Cylinder 4 MisfireAYe s
P0317Rough Road Sensor Source Not DetectedCnlNo
P0325Knock Sensor Internal MalfunctionCnlNo

ENGINE CONTROLS 1F – 385
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0135
FRONT HEATED OXYGEN SENSOR (HO2S1) HEATER
CIRCUIT NOT FUNCTIONING
Circuit Description
Heated oxygen sensors (HO2S) are used for fuel control
and post catalyst monitoring. Each HO2S compares the
oxygen content of the surrounding air with the oxygen con-
tent in the exhaust stream. The HO2S must reach operat-
ing temperature to provide an accurate voltage signal. A
heating element inside the HO2S minmizes the time re-
quired for the sensor to reach operating temperature. Volt-
age is provided to the heater by the ignition 1 voltage cir-
cuit through a fuse. With the engine running, ground is
provided to the heater by the HO2S heater low control cir-
cuit, through a low side driver within the engine control
module (ECM). The ECM monitors the current flow
through the heater for diagnosis.
If the ECM detects that the HO2S heater current is above
or blelow a specified range, DTC P0135 seats.
Conditions for Setting the DTC
S DTCs P0106, P0117, P0118, P1017 are not set.
S Engine run time is greater than 200 seconds.
S Filtered O2 heater current is less than 0.025 amps.
Action Taken When the DTC SetsS The Malfunction Indicator Lamp (MIL) will illuminate
after three consecutive ignition cycle with a fail.
S The ECM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Freeze Frame and Failure Records
buffers.
S A history Diagnostic Trouble Code (DTC) is stored.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after three consecutive ignition
cycles in which the diagnostic runs without a fault.
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
Diagnostic Aids
An intermittent may be caused by rubbed through wire in-
sulation or a wire contacting the exhaust.
Check for poor connection or damaged harness – inspect
harness connectors for the following conditions:
S Improper mating
S Broken locks
S Improperly formed
S Damaged terminals
S Poor terminal–to–wire connection