car key battery DAEWOO LACETTI 2004 Service Repair Manual

ENGINE ELECTRICAL 1E – 9
DAEWOO V–121 BL4
STARTER MOTOR NOISE
To correct starter motor noise during starting, use the following procedure:
Checks
Action
Check for a high–pitched whine during cranking, before
the engine fires. The engine cranks and fires properly.The distance is too great between the starter pinion and
the flywheel. Shimming the starter toward the flywheel is
required.
Check for a high–pitched whine after the engine fires, as
the key is being released. The engine cranks and fires
properly. This intermittent complaint is often diagnosed as
”starter hang–in” or ”solenoid weak.”The distance is too small between the starter pinion and
the flywheel. Shimming the starter away from the flywheel
is required.
Check for a loud ”whoop” after the engine fires but while
the starter is still held engaged. The sound is like a siren
if the engine is revved while the starter is engaged.The most probable cause is a defective clutch. A new
clutch will often correct this problem.
Check for a ”rumble,” a ”growl,” or, in severe cases, a
”knock” as the starter is coasting down to a stop after start-
ing the engine.The most probable cause is a bent or unbalanced starter
armature. A new armature will often correct this problem.
If the complaint is noise, correction can be achieved by
proper shimming as follows:
1. Check for a bent or a worn flywheel.
2. Start the engine and carefully touch the outside di-
ameter of the rotating flywheel ring gear with chalk
or a crayon to show the high point of the tooth run-
out. Turn the engine OFF and rotate the flywheel so
that the marked teeth are in the area of the starter
pinion gear.
3. Disconnect the negative battery cable to prevent
cranking the engine.
4. Check the pinion–to–flywheel clearance by using a
wire gauge of 0.5 mm (0.02 inch) minimum thick-
ness (or diameter). Center a pinion tooth between
two flywheel teeth and the gauge. Do not gauge in
the corners, where a misleading larger dimension
may be observed. If the clearance is under this
minimum, shimming the starter away from the fly-
wheel is required.
5. If the clearance approaches 1.5 mm (0.06 inch) or
more, shimming the starter toward the flywheel is
required. This condition is generally the cause of
broken flywheel teeth or the starter housing. Shim
the starter toward the flywheel by shimming only
the outboard starter mounting pad. A shim of 0.40
mm (0.016 inch) thickness at this location will de-
crease the clearance by approximately 0.30 mm
(0.012 inch). If normal starter shims are not avail-
able, plain washers or other suitable material may
be used as shims.BATTERY LOAD TEST
1. Check the battery for obvious damage, such as a
cracked or broken case or cover, which could per-
mit the loss of electrolyte. If obvious damage is
noted, replace the battery.
CAUTION : Do not charge the battery if the hydrome-
ter is clear or light yellow. Instead, replace the battery.
If the battery feels hot, or if violent gassing or spew-
ing of electrolyte through the vent hole occurs, dis-
continue charging or reduce the charging rate to
avoid personal injury.
2. Check the hydrometer. If the green dot is visible, go
to the load test procedure. If the indicator is dark
but green is not visible, charge the battery. For
charging a battery removed from the vehicle, refer
to ”Charging a Completely Discharged Battery” in
this section.
3. Connect a voltmeter and a battery load tester
across the battery terminals.
4. Apply a 300–ampere load for 15 seconds to remove
any surface charge from the battery.
5. Remove the load.
6. Wait 15 seconds to let the battery recover, and ap-
ply a 270–ampere load.
Important : The battery temperature must be estimated
by touch and by the temperature condition the battery has
been exposed for the preceding few hours.
7. If the voltage does not drop below the minimum
listed, the battery is good and should be reinstalled.
If the voltage is less than the minimum listed, re-
place the battery. Refer to ”Battery Specifications”
in this section.

1F – 106IENGINE CONTROLS
DAEWOO V–121 BL4
DATA LINK CONNECTOR DIAGNOSIS (1.4L/1.6L DOHC)
Circuit Description
The provision for communicating with the Engine Control
Module (ECM) is the Data Link Connector (DLC). It is lo-
cated under the instrument panel. The DLC is used to con-
nect the scan tool. Battery power and ground is supplied
for the scan tool through the DLC. The Keyword 2000 seri-
al data circuit to the DLC allows the ECM to communicate
with the scan tool. A Universal Asynchronous Receiver
Transmitter (UART) serial data line is used to communi-
cate with the other modules such as the Electronic Brake
Control Module (EBCM), the Supplemental Inflatable Re-
straint (SIR) system. and the Instrument Panel Cluster.
Diagnostic Aids
Ensure that the correct application (model line, car year,
etc.) has been selected on the scan tool. If communication
still cannot be established, try the scan tool on another ve-
hicle to ensure that the scan tool or cables are not the
cause of the condition.
An intermittent may be caused by a poor connection,
rubbed through wire insulation, or a broken wire inside the
insulation.
Any circuitry that is suspected of causing an intermittent
complaint should be thoroughly checked for the following
conditions:
S Backed–out terminals.S Improper mating of terminals.
S Broken locks.
S Improperly formed or damaged terminals.
S Poor terminal–to–wiring connection.
S Physical damage to the wiring harness.
S Corrosion.
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. Unlike the UART serial data circuit, the only time a
Class II serial data circuit has any voltage on it is
when a scan tool asks the ECM for information and
sends the information out.
5. Locate and repair any shorts that may have caused
the fuse to open before replacement, if the no volt-
age condition was due to an open fuse.
10. The scan tool or associated cables could be mal-
functioning. Refer to the scan tool’s manual for re-
pair information.

1F – 108IENGINE CONTROLS
DAEWOO V–121 BL4
DATA LINK CONNECTOR DIAGNOSIS (1.8L DOHC)
Circuit Description
The provision for communicating with the Engine Control
Module (ECM) is the Data Link Connector (DLC). It is lo-
cated under the instrument panel. The DLC is used to con-
nect the scan tool. Battery power and ground is supplied
for the scan tool through the DLC. The Keyword 2000 seri-
al data circuit to the DLC allows the ECM to communicate
with the scan tool. A Universal Asynchronous Receiver
Transmitter (UART) serial data line is used to communi-
cate with the other modules such as the Electronic Brake
Control Module (EBCM), the Supplemental Inflatable Re-
straint (SIR) system. and the Instrument Panel Cluster.
Diagnostic Aids
Ensure that the correct application (model line, car year,
etc.) has been selected on the scan tool. If communication
still cannot be established, try the scan tool on another ve-
hicle to ensure that the scan tool or cables are not the
cause of the condition.
An intermittent may be caused by a poor connection,
rubbed through wire insulation, or a broken wire inside the
insulation.
Any circuitry that is suspected of causing an intermittent
complaint should be thoroughly checked for the following
conditions:
S Backed–out terminals.S Improper mating of terminals.
S Broken locks.
S Improperly formed or damaged terminals.
S Poor terminal–to–wiring connection.
S Physical damage to the wiring harness.
S Corrosion.
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. Unlike the UART serial data circuit, the only time a
Class II serial data circuit has any voltage on it is
when a scan tool asks the ECM for information and
sends the information out.
5. Locate and repair any shorts that may have caused
the fuse to open before replacement, if the no volt-
age condition was due to an open fuse.
10. The scan tool or associated cables could be mal-
functioning. Refer to the scan tool’s manual for re-
pair information.