jump start terminals DAEWOO LACETTI 2004 Service Repair Manual

SECTION : 1E
ENGINE ELECTRICAL
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
SPECIFICATIONS1E–2 . . . . . . . . . . . . . . . . . . . . . . . . . .
Starter Specifications 1E–2. . . . . . . . . . . . . . . . . . . . . .
Battery Specifications 1E–2. . . . . . . . . . . . . . . . . . . . . .
Fastener Tightening Specifications 1E–3. . . . . . . . . .
SCHEMATIC AND ROUTING DIAGRAMS1E–4 . . . . .
Startimg System 1E–4. . . . . . . . . . . . . . . . . . . . . . . . . .
Charging System 1E–5. . . . . . . . . . . . . . . . . . . . . . . . . .
DIAGNOSIS1E–6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
No Crank 1E–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starter Motor Noise 1E–9. . . . . . . . . . . . . . . . . . . . . . .
Battery Load Test 1E–9. . . . . . . . . . . . . . . . . . . . . . . . .
Genrator Output Test 1E–10. . . . . . . . . . . . . . . . . . . . .
Generator System Check 1E–10. . . . . . . . . . . . . . . . .
MAINTENANCE AND REPAIR1E–11 . . . . . . . . . . . . . .
ON–VEHICLE SERVICE 1E–11. . . . . . . . . . . . . . . . . . . .
Generator 1E–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starter 1E–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Battery and Battery Tray 1E–15. . . . . . . . . . . . . . . . . . . UNIT REPAIR 1E–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starter Motor 1E–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Generator 1E–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GENERAL DESCRIPTION AND SYSTEM
OPERATION1E–30 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Battery 1E–30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ratings 1E–30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reserve Capacity 1E–30. . . . . . . . . . . . . . . . . . . . . . . . .
Cold Cranking Amperage 1E–30. . . . . . . . . . . . . . . . . .
Built–In Hydrometer 1E–30. . . . . . . . . . . . . . . . . . . . . . .
Charging Procedure 1E–30. . . . . . . . . . . . . . . . . . . . . . .
Charging Time Required 1E–31. . . . . . . . . . . . . . . . . . .
Charging a Completely Discharged Battery
(OFF the Vehicle) 1E–31. . . . . . . . . . . . . . . . . . . . . . .
Jump Starting Procedure 1E–31. . . . . . . . . . . . . . . . . .
Generator 1E–32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Charging System 1E–32. . . . . . . . . . . . . . . . . . . . . . . . .
Starter 1E–32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starting System 1E–32. . . . . . . . . . . . . . . . . . . . . . . . . .

ENGINE ELECTRICAL 1E – 7
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
151. Disconnect the neutral safety back–up (PNP)
switch.
2. Connect the negative voltmeter lead to the
PNP switch connector terminal E.
3. Connect the positive voltmeter lead to battery
positive.
Does the voltmeter indicate the value specified?11–14 vGo to Step 16Go to Step 19
161. Jumper the PNP switch connector terminals 9
and 10.
2. Connect the negative voltmeter lead to the igni-
tion switch.
3. Connect the positive voltmeter lead to battery
positive.
Does the voltmeter indicate the value specified?11–14 vGo to Step 17Go to Step 18
17Replace the neutral safety backup switch.
Is the repair complete?–System OK–
18Repair the wire as needed.
Is the repair complete?–System OK–
19Repair the open wire between the PNP switch con-
nector terminal E and ground.
Is the repair complete?–System OK–
201. Connect the voltmeter positive lead to the igni-
tion switch connector terminal 3 by backprob-
ing the connector.
2. Connect the voltmeter negative lead to ground.
Does the voltmeter indicate the value specified?11–14 vGo to Step 22Go to Step 21
21Repair the open in the wiring between the engine
block fuse Ef5 and the ignition switch connector ter-
minal 2.
Is the repair complete?–System OK–
221. Connect the voltmeter positive lead to the igni-
tion switch connector terminal 3 by backprob-
ing the connector.
2. Connect the voltmeter negative lead to ground.
3. Turn the ignition to START.
Does the voltmeter indicate the value specified?11–14 vGo to Step 23Go to Step 27
231. Connect the voltmeter positive lead to the igni-
tion switch connector terminal 3 by backprob-
ing the connector.
2. Connect the voltmeter negative lead to ground.
Does the voltmeter indicate the value specified?11–14 vGo to Step 25Go to Step 24
24Repair the open in the wiring between the engine
block fuse Ef5 and the ignition switch connector ter-
minal 3.
Is the repair complete?–System OK–
251. Connect the voltmeter positive lead to the igni-
tion switch connector terminal 3 by backprob-
ing the connector.
2. Connect the voltmeter negative lead to ground.
3. Turn the ignition to START.
Does the voltmeter indicate the value specified?11–14 vGo to Step 26Go to Step 27

1E – 10IENGINE ELECTRICAL
DAEWOO V–121 BL4
GENRATOR OUTPUT TEST
1. Perform the generator system test. Refer to ”Gen-
erator System Check”in this section.
2. Replace the generator if it fails that test. Refer to
”Generator” in the On–Vehicle Service portion of
this section. If it passes the test, perform the on–
vehicle output check which follows.
Important : Always check the generator for output before
assuming that a grounded ”L” terminal circuit has dam-
aged the regulator.
3. Attach a digital multimeter, an ammeter, and a car-
bon pile load to the vehicle.
Important : Be sure the vehicle battery is fully charged,
and the carbon pile load is turned off.
4. With the ignition switch in the OFF position, check
and record the battery voltage.
5. Remove the harness connector from the generator.
6. Turn the ignition to RUN with the engine not run-
ning. Use a digital multimeter to check for voltage in
the harness connector ”L” terminal.
7. The reading should be near the specified battery
voltage of 12 volts. If the voltage is too low, check
the indicator
L" terminal circuits for open and
grounded circuits causing voltage loss. Correct any
open wires, terminal connections, etc., as neces-
sary. Refer to”Charging System” in this section.
8. Attach the generator harness connector.
9. Run the engine at a moderate idle, and measure
the voltage across the battery terminals. The read-
ing should be above that recorded in step 14, but
less than 16 volts. If the reading is over 16 volts or
below the previous reading, replace the generator.
Refer to”Generator” in the On–Vehicle Service sec-
tion.
10. Run the engine at a moderate idle, and measure
the generator amperage output.
11. Turn on the carbon pile, and adjust it to obtain the
maximum amps while maintaining the battery volt-
age above 13 volts.
12. If the reading is within 15 amps of the generator’s
rating noted on the generator, the generator is
good. If not, replace the generator. Refer to”Gener-
ator” in the On–Vehicle Service section.
13. With the generator operating at the maximum out-
put, measure the voltage between the generator
housing and the battery negative terminal. The volt-
age drop should be 0.5 volt or less. If the voltage
drop is more than 0.5 volt, check the ground path
from the generator housing to the negative battery
cable.
14. Check, clean, tighten, and recheck all of the ground
connections.
GENERATOR SYSTEM CHECK
When operating normally, the generator indicator lamp will
come on when the ignition is in RUN position and go out
when the engine starts. If the lamp operates abnormally
or if an undercharged or overcharged battery condition oc-
curs, the following procedure may be used to diagnose the
charging system. Remember that an undercharged bat-
tery is often caused by accessories being left on overnight
or by a defective switch that allows a lamp, such as a trunk
or a glove box lamp, to stay on.
Diagnose the generator with the following procedure:
1. Visually check the belt and the wiring.
2. With the ignition in the ON position and the engine
stopped, the charge indicator lamp should be on. If
not, detach the harness at the generator and
ground the ”L” terminal in the harness with a 5–am-
pere jumper lead.
S If the lamp lights, replace the generator. Refer to
”Generator” in the On–Vehicle Service section.
S If the lamp does not light, locate the open circuit
between the ignition switch and the harness
connector. The indicator lamp bulb may be
burned out.
3. With the ignition switch in the ON position and the
engine running at moderate speed, the charge indi-
cator lamp should be off. If not, detach the wiring
harness at the generator.
S If the lamp goes off, replace the generator. Re-
fer to ”Generator” in the On–Vehicle Service
section.
S If the lamp stays on, check for a short to ground
in the harness between the connector and the
indicator lamp.
Important : Always check the generator for output before
assuming that a grounded ”L” terminal circuit has dam-
aged the regulator. Refer to”Generator” in the Unit Repair
section.

ENGINE ELECTRICAL 1E – 31
DAEWOO V–121 BL4
trolyte and the plates are at room temperature. A
battery that is extremely cold may not accept cur-
rent for several hours after starting the charger.
3. Charge the battery until the green dot appears. The
battery should be checked every half–hour while
charging. Tipping or shaking the battery may be
necessary to make the green dot appear.
4. After charging, the battery should be load tested.
Refer to ”Starter Motor” in this section.
CHARGING TIME REQUIRED
The time required to charge a battery will vary depending
upon the following factors:
S Size of Battery – A completely discharged large
heavy–duty battery requires more than twice the re-
charging time as a completely discharged small pas-
senger car battery.
S Temperature – A longer time will be needed to
charge any battery at –18°C (0°F) than at 27°C
(80°F). When a fast charger is connected to a cold
battery, the current accepted by the battery will be
very low at first. The battery will accept a higher cur-
rent rate as the battery warms.
S Charger Capacity – A charger which can supply only
5 amperes will require a much longer charging period
than a charger that can supply 30 amperes or more.
S State–of–Charge – A completely discharged battery
requires more than twice as much charge as a one–
half charged battery. Because the electrolyte is nearly
pure water and a poor conductor in a completely dis-
charged battery, the current accepted by the battery
is very low at first. Later, as the charging current
causes the electrolyte acid content to increase, the
charging current will likewise increase.
CHARGING A COMPLETELY
DISCHARGED BATTERY (OFF THE
VEHICLE)
Unless this procedure is properly followed, a perfectly
good battery may need to be replaced.
The following procedure should be used to recharge a
completely discharged battery:
1. Measure the voltage at the battery terminals with
an accurate voltmeter. If the reading is below 10
volts, the charge current will be very low, and it
could take some time before the battery accepts
the current in excess of a few milliamperes. Refer
to ””Charging Time Required” in this section, which
focuses on the factors affecting both the charging
time required and the rough estimates in the table
below. Such low current may not be detectable on
ammeters available in the field.
2. Set the battery charger on the high setting.Important : Some chargers feature polarity protection cir-
cuitry, which prevents charging unless the charger leads
are correctly connected to the battery terminals. A com-
pletely discharged battery may not have enough voltage
to activate this circuitry, even though the leads are con-
nected properly, making it appear that the battery will not
accept charging current. Therefore, follow the specific
charger manufacturer’s instruction for bypassing or over-
riding the circuitry so that the charger will turn on and
charge a low–voltage battery.
3. Continue to charge the battery until the charge cur-
rent is measurable. Battery chargers vary in the
amount of voltage and current provided. The time
required for the battery to accept a measurable
charge current at various voltages may be as fol-
lows:
Voltage
Hours
16.0 or moreUp to 4 hours
14.0–15.9Up to 8 hours
13.9 or lessUp to 16 hours
S If the charge current is not measurable at the
end of the above charging times, the battery
should be replaced.
S If the charge current is measurable during the
charging time, the battery is good, and charging
should be completed in the normal manner.
Important : It is important to remember that a completely
discharged battery must be recharged for a sufficient num-
ber of ampere hours (AH) to restore the battery to a usable
state. As a general rule, using the reserve capacity rating
(RC) as the number of ampere hours of charge usually
brings the green dot into view.
S If the charge current is still not measurable after
using the charging time calculated by the above
method, the battery should be replaced.
JUMP STARTING PROCEDURE
1. Position the vehicle with the good (charged) battery
so that the jumper cables will reach.
2. Turn off the ignition, all the lights, and all the electri-
cal loads in both vehicles. Leave the hazard flasher
on if jump starting where there may be other traffic
and any other lights needed for the work area.
3. In both vehicles, apply the parking brake firmly.
Notice : To avoid vehicle damage,Make sure the cables
are not on or near pulleys, fans, or other parts that will
move when the engine starts.
4. Shift an automatic transaxle to PARK, or a manual
transaxle to NEUTRAL.
CAUTION : In order to avoid injury, do not use cables
that have loose or missing insulation.
5. Clamp one end of the first jumper cable to the posi-
tive terminal on the battery. Make sure it does not
touch any other metal parts. Clamp the other end of

1F – 246IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
41. Turn the ignition switch to LOCK.
2. Disconnect the relay.
3. Using a DVM, measure the resistance between
terminals 85 and 10 in the relay control circuit
in the ECM harness connector to ground.
Does the DVM display infinite resistance?–Go to Step 12Go to Step 10
51. Turn the ignition switch to LOCK.
2. Disconnect the relay.
3. Connect a test light between the relay coil ter-
minals 86 and 85 in the relay harness connec-
tor.
4. Turn the Turn the ignition switch to ON.
5. Using the scan tool, command the relay ON
and OFF.
Does the test light turn ON and OFF with each com-
manded?–Go to Step 8Go to Step 6
6With the test light connected to ground, probe the
ignition feed circuit in the relay harness connector.
Does the test light illuminate?–Go to Step 7Go to Step 11
71. Turn the ignition switch to LOCK.
2. Reconnect the relay.
3. Disconnect the ECM connector containing the
relay control circuit.
4. Turn the Turn the ignition switch to ON.
5. With a fused jumper wire connected to ground,
probe the relay control circuit at terminal 10 in
the ECM harness connector.
Does the relay operate?–Go to Step 9Go to Step 10
8Check the connections at the relay.
Is a problem found and corrected?–Go to Step 14Go to Step 12
9Check the connection at the ECM.
Is a problem found and corrected?–Go to Step 11Go to Step 13
10Repair the faulty relay control circuit.
Is the repair complete?–Go to Step 14–
11Repair the faulty relay ignition feed circuit.
Is the repair complete?–Go to Step 14–
12Replace the relay.
Is the replacement complete?–Go to Step 14–
13Replace the ECM.
Is the replacement complete?–Go to Step 14–
141. Using the scan tool, clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the conditions for
setting the DTC as specifiec in the supporting
text.
Does the scan tool indicate that this diagnostic ran
and passed?–Go to Step 15Go to Step 2
15Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

ENGINE CONTROLS 1F – 249
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
41. Turn the ignition switch to LOCK.
2. Disconnect the relay.
3. Using a DVM, measure the resistance between
terminals 85 and 10 in the relay control circuit
in the ECM harness connector to ground.
Does the DVM display infinite resistance?–Go to Step 12Go to Step 10
51. Turn the ignition switch to LOCK.
2. Disconnect the relay.
3. Connect a test light between the relay coil ter-
minals 86 and 85 in the relay harness connec-
tor.
4. Turn the Turn the ignition switch to ON.
5. Using the scan tool, command the relay ON
and OFF.
Does the test light turn ON and OFF with each com-
manded?–Go to Step 8Go to Step 6
6With the test light connected to ground, probe the
ignition feed circuit in the relay harness connector.
Does the test light illuminate?–Go to Step 7Go to Step 11
71. Turn the ignition switch to LOCK.
2. Reconnect the relay.
3. Disconnect the ECM connector containing the
relay control circuit.
4. Turn the Turn the ignition switch to ON.
5. With a fused jumper wire connected to ground,
probe the relay control circuit at terminal 10 in
the ECM harness connector.
Does the relay operate?–Go to Step 9Go to Step 10
8Check the connections at the relay.
Is a problem found and corrected?–Go to Step 14Go to Step 12
9Check the connection at the ECM.
Is a problem found and corrected?–Go to Step 11Go to Step 13
10Repair the faulty relay control circuit.
Is the repair complete?–Go to Step 14–
11Repair the faulty relay ignition feed circuit.
Is the repair complete?–Go to Step 14–
12Replace the relay.
Is the replacement complete?–Go to Step 14–
13Replace the ECM.
Is the replacement complete?–Go to Step 14–
141. Using the scan tool, clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the conditions for
setting the DTC as specifiec in the supporting
text.
Does the scan tool indicate that this diagnostic ran
and passed?–Go to Step 15Go to Step 2
15Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

1F – 252IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
41. Turn the ignition switch to LOCK.
2. Disconnect the relay.
3. Using a DVM, measure the resistance between
terminals 85 and 9 in the relay control circuit in
the ECM harness connector to ground.
Does the DVM display infinite resistance?–Go to Step 12Go to Step 10
51. Turn the ignition switch to LOCK.
2. Disconnect the relay.
3. Connect a test light between the relay coil ter-
minals 86 and 85 in the relay harness connec-
tor.
4. Turn the Turn the ignition switch to ON.
5. Using the scan tool, command the relay ON
and OFF.
Does the test light turn ON and OFF with each com-
manded?–Go to Step 8Go to Step 6
6With the test light connected to ground, probe the
ignition feed circuit in the relay harness connector.
Does the test light illuminate?–Go to Step 7Go to Step 11
71. Turn the ignition switch to LOCK.
2. Reconnect the relay.
3. Disconnect the ECM connector containing the
relay control circuit.
4. Turn the Turn the ignition switch to ON.
5. With a fused jumper wire connected to ground,
probe the relay control circuit at terminal 9 in
the ECM harness connector.
Does the relay operate?–Go to Step 9Go to Step 10
8Check the connections at the relay.
Is a problem found and corrected?–Go to Step 14Go to Step 12
9Check the connection at the ECM.
Is a problem found and corrected?–Go to Step 11Go to Step 13
10Repair the faulty relay control circuit.
Is the repair complete?–Go to Step 14–
11Repair the faulty relay ignition feed circuit.
Is the repair complete?–Go to Step 14–
12Replace the relay.
Is the replacement complete?–Go to Step 14–
13Replace the ECM.
Is the replacement complete?–Go to Step 14–
141. Using the scan tool, clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the conditions for
setting the DTC as specifiec in the supporting
text.
Does the scan tool indicate that this diagnostic ran
and passed?–Go to Step 15Go to Step 2
15Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

1F – 350IENGINE CONTROLS
DAEWOO V–121 BL4
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 will determine if DTC P0107 is the result
of a hard failure or an intermittent condition.
3. Jumpering harness terminals 2 to 1 (signal circuit to
5 volts) will determine if the sensor is malfunction-
ing or if there is a problem with the ECM or wiring.6. The scan tool may not display 5 volts. The Impor-
tant thing is that the ECM recognizes the voltage as
more than 4 volts, indicating that the ECM and the
signal circuit are OK. A test light that illuminates
indicates a short to ground in the signal circuit.
7. A short to ground in the 5 volt reference circuit
could also set additional DTCs.
11. The replacement ECM must be programmed. Refer
to the latest Techline procedure for the ECM repro-
gramming.
DTC P0107 Manifold Absolute Pressure Low Voltage
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Install a scan tool to the Data Link Connector
(DLC).
2. Start the engine.
3. Read the Manifold Absolute Pressure (MAP).
Does the scan tool display a MAP below the speci-
fied value?12 kPaGo to Step 3Go to Step 4
31. Turn the ignition switch OFF.
2. Disconnect the MAP sensor electrical connec-
tor.
3. Jumper the MAP signal circuit at terminal 2 to
the 5 volt reference circuit at terminal 1.
4. Turn the ignition switch ON.
Does the MAP read more than the specified value?96 kPaGo to Step 5Go to Step 6
41. Turn the ignition switch ON with the engine
OFF, review the Freeze Frame data, and note
the parameters.
2. Operate the vehicle within the freeze frame
conditions and Conditions For Setting the DTC
as noted.
Does the scan tool display MAP below the specified
value?12 kPaGo to Step 3Go to
”Diagnostic
Aids”
5Inspect the MAP sensor harness electrical connec-
tor terminals for the following conditions:
S Poor connections.
S Proper contact tension.
S Poor terminal to wire connection.
Is a problem found?–Go to Step 8Go to Step 9
61. Turn the ignition switch OFF.
2. Remove the jumper wire.
3. Probe the MAP sensor signal circuit terminal 2
with a test light to B+.
4. Turn the ignition switch ON.
Does the scan tool read over the specified value?90 kPaGo to Step 7Go to Step 12
7Check the MAP sensor 5 volt reference circuit at ter-
minal 1 for an open or short to ground.
Is a problem found?–Go to Step 10Go to Step 11

ENGINE CONTROLS 1F – 389
DAEWOO V–121 BL4
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 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 The DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
An intermittent may be caused by rubbed–through wire in-
sulation or a wire contacting the exhaust.
Check for the following conditions:
S Exhaust system – Inspect the exhaust system for
leaks. Check the exhaust between the three–way
catalytic converter and the flange for leaks, corro-
sion, or for loose or missing hardware and repair as
necessary.
S Poor connection or damaged harness – Ensure that
the HO2S2 pigtail is not contacting the exhaust.
Check for the following conditions:
S Improper mating
S Broken locks
S Improperly formedS Damaged terminals
S Poor terminal–to–wire connection
S Damaged harness
S Intermittent test – Observe the HO2S2 on the scan
tool while moving related connections and the wir-
ing harness with the ignition ON. If the failure is in-
duced, the HO2S2 display will change. This may
help isolate the location of the malfunction.
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 P0137 is the result of
a hard failure or an intermittent condition.
4. Jumping the HO2S2 low circuit, terminal 4 to
ground is necessary to allow the ECM to display
the supplied bias voltage. If the voltage is between
0.35 and 0.55 volt, then the wiring and ECM are
OK.
6. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
DTC P0137 – Rear Heated Oxygen Sensor (HO2S2) Low Voltage
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Install a scan tool to the Data Link Connector
(DLC).
2. Turn the ignition ON.
Is the Rear Heated Oxygen Sensor (HO2S2) volt-
age less than the value specified?0.1 VGo to Step 4Go to Step 3
31. Start the engine.
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.
Is the HO2S2 voltage less than the specified value?0.4 VGo to Step 4Go to Step 8
41. Turn the ignition OFF.
2. Disconnect HO2S2 connector.
3. Connect a jumper wire between terminal 1 of
HO2S2 connector and ground.
4. Turn the ignition ON.
Does the scan tool indicate that the HO2S2 voltage
is within the specified value?350–550 mVGo to Step 7Go to Step 5

ENGINE CONTROLS 1F – 393
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
51. Reconnect the ECM connector.
2. Turn the ignition ON.
3. Jumper the high and low circuits at the HO2S2
connector, terminals 1 and 2 to ground.
Does the scan tool indicate the HO2S2 voltage be-
low the specified value?0.1 VGo to Step 7Go to Step 8
6Repair the short to voltage in the HO2S2 high circuit.
Is the repair complete?–Go to Step 9–
7S Turn the ignition OFF.
S Replace the HO2S2.
Is the repair complete?–Go to Step 9–
8S Turn the ignition OFF.
S Replace the ECM.
Is the repair complete?–Go to Step 9–
91. Using the scan tool, clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the Conditions for
setting this DTC as specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?–Go to Step 10Go to Step 2
10Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK