Page 577 of 2643

ENGINE CONTROLS 1F – 331
DAEWOO V–121 BL4
DTC P1610 – Main Relay High Voltage (1.6L DOHC)
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Disconnect the main relay.
2. Measure the resistance between main relay
terminals 85 and 86.
Does the resistance within the specified value?75~85WGo to Step 3Go to Step 6
31. Turn the ignition switch to LOCK.
2. With the test light, connected to ground, probe
the ignition feed circuit, at terminal 85 in the
relay harness connector.
Does the test light illuminate?–Go to Step 4Go to
”Diagnostic
Aids”
41. Turn the ignition switch to LOCK.
2. Disconnect the ECM wiring harness connector.
3. With the test light, connected to ground, probe
the ignition feed circuit, at terminal 85 in the
relay harness connector.
Does the test light illuminate?–Go to Step 5Go to Step 7
5Repair a high voltage between the ECM wiring con-
nector terminal 7 and main relay terminal 85.
Is the repair complete?–Go to Step 7–
6Replace the main relay.
Is the replacement complete?–Go to Step 7–
71. 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 8Go to Step 2
8Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
applicable DTC
tableSystem OK
Page 578 of 2643

1F – 332IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1611
MAIN RELAY LOW VOLTAGE (1.4L DOHC)
Circuit Description
When the ignition switch to ON, main relay will grounded
to ECM internal ground by ECM controlling.
A system voltage Diagnostic Trouble Code (DTC) will set
whenever the voltage is below a calibrated value.
Conditions for Setting the DTC
S The main relay circuit is a short to ground or an
open condition exists.
Action Taken When the DTCs Sets
S The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
S The ECM will store conditions which were present
when the DTC was set as Failure Records data
only.
S This information will not be stored in the Freeze
Frame data.
Conditions for Clearing the MIL/DTCS 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
Inspect harness connectors for backed–out terminals, im-
proper mating, broken locks, improperly formed or dam-
aged terminals, and poor terminal–to–wire connection at
the ECM.
Inspect the wiring harness for damage. If the harness ap-
pears to be OK, observe the A/C pressure display on the
scan tool while moving the connectors and wiring har-
nesses related to the ACP sensor. A change in the A/C
pressure display will indicate the location of the fault.
If DTC P1611 cannot be duplicated, reviewing the Fail Re-
cords vehicle mileage since the diagnostic test last failed
may help determine how often the condition that caused
the DTC to set occurs. This may assist in diagnosing the
condition.
Page 579 of 2643

ENGINE CONTROLS 1F – 333
DAEWOO V–121 BL4
DTC P1611 – Main Relay Low Voltage (1.4L DOHC)
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Disconnect the main relay.
2. Measure the resistance between main relay
terminals 85 and 86.
Does the resistance within the specified value?75~85WGo to Step 3Go to Step 6
31. Turn the ignition switch to LOCK.
2. With the test light, connected to ground, probe
the ignition feed circuit, at terminal 85 in the
relay harness connector.
Does the test light illuminate?–Go to Step 4Go to
”Diagnostic
Aids”
41. Turn the ignition switch to LOCK.
2. Disconnect the ECM wiring harness connector.
3. With the test light, connected to ground, probe
the ignition feed circuit, at terminal 85 in the
relay harness connector.
Does the test light illuminate?–Go to Step 5Go to Step 7
5Repair a high voltage between the ECM wiring con-
nector terminal 7 and main relay terminal 85.
Is the repair complete?–Go to Step 7–
6Replace the main relay.
Is the replacement complete?–Go to Step 7–
71. 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 8Go to Step 2
8Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
applicable DTC
tableSystem OK
Page 580 of 2643

1F – 334IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1611
MAIN RELAY LOW VOLTAGE (1.6L DOHC)
Circuit Description
When the ignition switch to ON, main relay will grounded
to ECM internal ground by ECM controlling.
A system voltage Diagnostic Trouble Code (DTC) will set
whenever the voltage is below a calibrated value.
Conditions for Setting the DTC
S The main relay circuit is a short to ground or an
open condition exists.
Action Taken When the DTCs Sets
S The Malfunction Indicator Lamp (MIL) will illumi-
nate.
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 Using the scan tool can clear DTC(s).
S Disconnecting the ECM battery feed for 10 sec-
onds.
Diagnostic Aids
Inspect harness connectors for backed–out terminals, im-
proper mating, broken locks, improperly formed or dam-
aged terminals, and poor terminal–to–wire connection at
the ECM.
Inspect the wiring harness for damage. If the harness ap-
pears to be OK, observe the A/C pressure display on the
scan tool while moving the connectors and wiring har-
nesses related to the ACP sensor. A change in the A/C
pressure display will indicate the location of the fault.
If DTC P1611 cannot be duplicated, reviewing the Fail Re-
cords vehicle mileage since the diagnostic test last failed
may help determine how often the condition that caused
the DTC to set occurs. This may assist in diagnosing the
condition.
Page 581 of 2643

ENGINE CONTROLS 1F – 335
DAEWOO V–121 BL4
DTC P1611 – Main Relay Low Voltage (1.6L DOHC)
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Disconnect the main relay.
2. Measure the resistance between main relay
terminals 85 and 86.
Does the resistance within the specified value?75~85WGo to Step 3Go to Step 6
31. Turn the ignition switch to LOCK.
2. With the test light, connected to ground, probe
the ignition feed circuit, at terminal 85 in the
relay harness connector.
Does the test light illuminate?–Go to Step 4Go to
”Diagnostic
Aids”
41. Turn the ignition switch to LOCK.
2. Disconnect the ECM wiring harness connector.
3. With the test light, connected to ground, probe
the ignition feed circuit, at terminal 85 in the
relay harness connector.
Does the test light illuminate?–Go to Step 5Go to Step 7
5Repair a high voltage between the ECM wiring con-
nector terminal 7 and main relay terminal 85.
Is the repair complete?–Go to Step 7–
6Replace the main relay.
Is the replacement complete?–Go to Step 7–
71. 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 8Go to Step 2
8Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
applicable DTC
tableSystem OK
Page 582 of 2643

1F – 336IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1628
IMMOBILIZER NO SUCCESSFUL COMMUNICATION
Circuit Description
When the ignition switch is turned to ON, the key tested
by immobilizer anti–theft system. While the key code is be-
ing read by immobilizer control unit or integrated anti–theft
control unit, the engine can start run with any key that will
turn the lock cylinder. the key code is read and compared
with key codes that have been stored in the memory of the
immobilizer control unit. If a valid key is detected, the im-
mobilizer control unit sends a serial data release message
to the Engine Control Module (ECM). Included in the re-
lease message is an identification (ID) code which as-
sures that neither the immobilizer control unit nor the ECM
have been substituted to defeat the system. If the ECM re-
ceives an invalid release message, the ECM performs the
following action:
S Disable the fuel injector circuit.
S Disable the fuel pump circuit.
S Disable the ignition coil.
S A Diagnostic Trouble Code (DTC) will stored if de-
tect communication link failure between the ECM
and immobilizer control unit.Conditions for Setting the DTC
S No safety security strategy allowed.
S Time–out delay has elapsed without successful
communication or a transmission key ON/OFF oc-
curred before a successful communication.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
S The ECM will store conditions which were present
when the DTC was set as Failure Records data
only.
S This information will not be stored in the Freeze
Frame data.
Conditions for Clearing the MIL/DTC
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.
Page 583 of 2643

ENGINE CONTROLS 1F – 337
DAEWOO V–121 BL4
DTC P1628 – Immobilizer No Successful Communication
StepActionValue(s)YesNo
1Perform an 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 OFF.
2. Install a scan too to the Data Link Connector
(DLC).
3. Turn the ignition ON.
4. Select IMMOBILIZER DIAGNOSIS STATUS
from the scan tool menu.
Is the communication established between the scan
tool and the immobilizer control unit?–Go to Step 3Go to
Section 9T, Im-
mobillzer Anti–
Theft System
31. Turn the ignition OFF.
2. Disconnect the Immobilizer Control Unit and
Engine Control Module (ECM) connectors.
3. Measure the resistance between terminal 7 of
immoblizer control unit and terminal 56 of the
ECM.
Is the resistance within the specified value?0WGo to Step 5Go to Step 4
4Repair an open circuit between terminal 7 of immobi-
lizer control unit and terminal 56 of the ECM.
Is the repair complete?–Go to Step 8–
5Check the terminals in immobilizer control unit and
the ECM for damages and repair as needed.
Is the repair complete?–Go to Step 8Go to Step 6
6Replace the immobilizer control unit.
Is the repair complete?–Go to Step 8Go to Step 7
71. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 8–
81. 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 9Go to Step 2
9Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
applicable DTC
tableSystem OK
Page 584 of 2643

1F – 338IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1629
IMMOBILIZER WRONG COMPUTATION
Circuit Description
When the ignition switch is turned to ON, the key tested
by immobilizer anti–theft system. While the key code is be-
ing read by immobilizer control unit or integrated anti–theft
control unit, the engine can start run with any key that will
turn the lock cylinder. the key code is read and compared
with key codes that have been stored in the memory of the
immobilizer control unit. If a valid key is detected, the im-
mobilizer control unit sends a serial data release message
to the Engine Control Module (ECM). Included in the re-
lease message is an identification (ID) code which as-
sures that neither the immobilizer control unit nor the ECM
have been substituted to defeat the system. If the ECM re-
ceives an invalid release message, the ECM performs the
following action:
S Disable the fuel injector circuit.
S Disable the fuel pump circuit.
S Disable the ignition coil.A Diagnostic Trouble Code (DTC) will stored if detect com-
munication link failure between the ECM and immobilizer
control unit.
Conditions for Setting the DTC
S Wrong coded value from ICU.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
S The ECM will store conditions which were present
when the DTC was set as Failure Records data
only.
S This information will not be stored in the Freeze
Frame data.
Conditions for Clearing the MIL/DTC
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.