2004 DAEWOO LACETTI Ground

1F – 408IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0201
INJECTOR 1 CIRCUIT FAULT
Circuit Description
The Engine Control Module (ECM) has four individual in-
jector driver circuits, each of which controls an injector.
When a driver circuit is grounded by the ECM, the injector
is activated. The ECM monitors the current in each driver
circuit. The ECM measures a voltage drop through a fixed
resistor and controls it. The voltage on each driver is moni-
tored to detect a fault. If the voltage is not what the ECM
expects to monitor on the circuit, a Diagnostic Trouble
Code (DTC) is set. This DTC detects a short to ground
and/or an open circuit and short to battery conditions for
low–side drive injector outputs.
Conditions for Setting the DTC
S Monitor fault feedback signal from FETS.
S Engine is in run mode.
S Battery voltage is greater than 9 volts.
S Engine speed is greater than 700 rpm.
S Fault is present for more than 5 seconds.
Action Taken When the DTC Sets
S The ECM will illuminate the Malfunction Indicator
Lamp (MIL) the first time the fault is Detected.S The ECM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC
S The ECM will turn off the MIL on the third consecu-
tive trip cycle in which the diagnostic has been run
and the fault is no longer present.
S A history will clear after 40 consecutive warm–up
cycles without a fault.
S DTC can be cleared by using the scan tool Clear
Info function.
S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
An injector 1 driver circuit that is open or shorted to voltage
will cause a DTC P0201 to set. It will also cause a misfire
due to an inoperative injector. A misfire DTC should also
be set indicating which injector is inoperative.
Long–term and short–term fuel trims that are excessively
high or low are a good indication that an injector is mal-
functioning. Refer to ”Fuel Injector Balance Test” in this
section to check for malfunctioning injectors.

ENGINE CONTROLS 1F – 409
DAEWOO V–121 BL4
The injector resistance tested at the ECM connection is
slightly more than if tested directly at the injector because
it includes resistance of the harness wires. The normal val-
ue is about 13.5 Ω
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. Thiscreates an electronic copy of the data taken when
the malfunction occurred. The information is then
stored on the scan tool for later reference.
3. This step determines if DTC P0201 is the result of
a hard failure or an intermittent condition.
5. This step tests the wiring harness and the ECM
control of the injectors using a test light.
7. This step determines if the circuitry is shorted to
voltage or the ECM is faulty.
9. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
DTC P0201 – Injector 1 Circuit Fault
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”
2Will the engine start?–Go to Step 3Go to
”Engine Cranks
But Will Not
Run”
31. Install a scan tool to the Data Link Connector
(DLC).
2. Turn the ignition ON, with the engine OFF.
3. Clear the Diagnostic Trouble Codes (DTCs)
using a scan tool.
4. Start the engine and idle for one minute.
Does DTC P0201 reset?–Go to Step 5Go to Step 4
41. Turn the ignition ON, with the engine OFF.
2. Review the Freeze Frame data and note the
parameters.
3. Operate the vehicle within the Freeze Frame
conditions as noted.
Does DTC P0201 reset?–Go to Step 5Go to
”Diagnostic
Aids”
51. Turn the ignition OFF.
2. Disconnect the Engine Control Module (ECM)
connector for injector 1.
3. Turn the ignition ON, with the engine OFF.
4. With a test light connected to ground, probe
the driver circuit, terminal M25.
Does the test light illuminate?–Go to Step 7Go to Step 6
6Repair the short to ground or open in the injector
driver circuit.
Is the repair complete?–Go to Step 10–
71. Disconnect the injector 1 wiring connection.
2. With a test light connected to ground, probe
the driver circuit, terminal 1.
Does the test light illuminate?–Go to Step 8Go to Step 9
8Repair the short to voltage in the injector driver cir-
cuit.
Is the repair complete?–Go to Step 10–

ENGINE CONTROLS 1F – 411
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0202
INJECTOR 2 CIRCUIT FAULT
Circuit Description
The Engine Control Module (ECM) has four individual in-
jector driver circuits, each of which controls an injector.
When a driver circuit is grounded by the ECM, the injector
is activated. The ECM monitors the current in each driver
circuit. The ECM measures a voltage drop through a fixed
resistor and controls it. The voltage on each driver is moni-
tored to detect a fault. If the voltage is not what the ECM
expects to monitor on the circuit, a Diagnostic Trouble
Code (DTC) is set. This DTC detects a short to ground
and/or an open circuit and short to battery conditions for
low–side drive injector outputs.
Conditions for Setting the DTC
S Monitor fault feedback signal from FETS.
S Engine is in run mode.
S Battery voltage is greater than 9 volts.
S Engine speed is greater than 700 rpm.
S Fault is present for more than 5 seconds.
Action Taken When the DTC Sets
S The ECM will illuminate the Malfunction Indicator
Lamp (MIL) the first time the fault is Detected.S The ECM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC
S The ECM will turn off the MIL on the third consecu-
tive trip cycle in which the diagnostic has been run
and the fault is no longer present.
S A history will clear after 40 consecutive warm–up
cycles without a fault.
S DTC can be cleared by using the scan tool Clear
Info function.
S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
An injector 2 driver circuit that is open or shorted to voltage
will cause a DTC P0202 to set. It will also cause a misfire
due to an inoperative injector. A misfire DTC should also
be set indicating which injector is inoperative.
Long–term and short–term fuel trims that are excessively
high or low are a good indication that an injector is mal-
functioning. Refer to ”Fuel injector Balance Test” in this
section to check for malfunctioning injectors.

1F – 412IENGINE CONTROLS
DAEWOO V–121 BL4
The injector resistance tested at the ECM connection is
slightly more than if tested directly at the injector because
it includes resistance of the harness wires. The normal val-
ue is about 13.5 Ω
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. Thiscreates an electronic copy of the data taken when
the malfunction occurred. The information is then
stored on the scan tool for later reference.
3. This step determines if DTC P0201 is the result of
a hard failure or an intermittent condition.
5. This step tests the wiring harness and the ECM
control of the injectors using a test light.
7. This step determines if the circuitry is shorted to
voltage or the ECM is faulty.
9. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
DTC P0202 – Injector 2 Circuit Fault
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”
2Will the engine start?–Go to Step 3Go to
”Engine Cranks
But Will Not
Run”
31. Install a scan tool to the Data Link Connector
(DLC).
2. Turn the ignition ON, with the engine OFF.
3. Clear the Diagnostic Trouble Codes (DTCs)
using a scan tool.
4. Start the engine and idle for one minute.
Does DTC P0202 reset?–Go to Step 5Go to Step 4
41. Turn the ignition ON, with the engine OFF.
2. Review the Freeze Frame data and note the
parameters.
3. Operate the vehicle within the Freeze Frame
conditions as noted.
Does DTC P0202 reset?–Go to Step 5Go to
”Diagnostic
Aids”
51. Turn the ignition OFF.
2. Disconnect the Engine Control Module (ECM)
connector for injector 2.
3. Turn the ignition ON, with the engine OFF.
4. With a test light connected to ground, probe
the driver circuit, terminal M22.
Does the test light illuminate?–Go to Step 7Go to Step 6
6Repair the short to ground or open in the injector
driver circuit.
Is the repair complete?–Go to Step 10
71. Disconnect the injector 2 wiring connection.
2. With a test light connected to ground, probe
the driver circuit, terminal 1.
Does the test light illuminate?–Go to Step 8Go to Step 9
8Repair the short to voltage in the injector driver cir-
cuit.
Is the repair complete?–Go to Step 10–

1F – 414IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0203
INJECTOR 3 CIRCUIT FAULT
Circuit Description
The Engine Control Module (ECM) has four individual in-
jector driver circuits, each of which controls an injector.
When a driver circuit is grounded by the ECM, the injector
is activated. The ECM monitors the current in each driver
circuit. The ECM measures a voltage drop through a fixed
resistor and controls it. The voltage on each driver is moni-
tored to detect a fault. If the voltage is not what the ECM
expects to monitor on the circuit, a Diagnostic Trouble
Code (DTC) is set. This DTC detects a short to ground
and/or an open circuit and short to battery conditions for
low–side drive injector outputs.
Conditions for Setting the DTC
S Monitor fault feedback signal from FETS.
S Engine is in run mode.
S Battery voltage is greater than 9 volts.
S Engine speed is greater than 700 rpm.
S Fault is present for more than 5 seconds.
Action Taken When the DTC Sets
S The ECM will illuminate the Malfunction Indicator
Lamp (MIL) the first time the fault is Detected.S The ECM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC
S The ECM will turn off the MIL on the third consecu-
tive trip cycle in which the diagnostic has been run
and the fault is no longer present.
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S DTC can be cleared by using the scan tool Clear
Info function.
S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
An injector 3 driver circuit that is open or shorted to voltage
will cause a DTC P0203 to set. It will also cause a misfire
due to an inoperative injector. A misfire DTC should also
be set indicating which injector is inoperative.
Long–term and short–term fuel trims that are excessively
high or low are a good indication that an injector is mal-
functioning. Refer to ”Fuel injector Balance Test” in this
section to check for malfunctioning injectors.

ENGINE CONTROLS 1F – 415
DAEWOO V–121 BL4
The injector resistance tested at the ECM connection is
slightly more than if tested directly at the injector because
it includes resistance of the harness wires. The normal val-
ue is about 13.5 Ω.
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. Thiscreates an electronic copy of the data taken when
the malfunction occurred. The information is then
stored on the scan tool for later reference.
3. This step determines if DTC P0203 is the result of
a hard failure or an intermittent condition.
5. This step tests the wiring harness and ECM control
of the injectors using a test light.
7. This step determines if the circuitry is shorted to
voltage or the ECM is faulty.
9. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
DTC P0203 – Injector 3 Circuit Fault
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”
2Will the engine start?–Go to Step 3Go to
”Engine Cranks
But Will Not
Run”
31. Install a scan tool to the Data Link Connector
DLC).
2. Turn the ignition ON, with the engine OFF.
3. Clear the Diagnostic Trouble Codes (DTCs)
using a scan tool.
4. Start the engine and idle for one minute.
Does DTC P0203 reset?–Go to Step 5Go to Step 4
41. Turn the ignition ON, with the engine OFF.
2. Review the Freeze Frame data and note the
parameters.
3. Operate the vehicle within the Freeze Frame
conditions as noted.
Does DTC P0203 reset?–Go to Step 5Go to
”Diagnostic
Aids”
51. Turn the ignition OFF.
2. Disconnect the Engine Control Module (ECM)
connector for injector 3.
3. Turn the ignition ON, with the engine OFF.
4. With a test light connected to ground, probe
the driver circuit, terminal M24.
Does the test light illuminate?–Go to Step 7Go to Step 6
6Repair the short to ground or open in the injector
driver circuit.
Is the repair complete?–Go to Step 10–
71. Disconnect the injector 3 wiring connection.
2. With a test light connected to ground, probe
the driver circuit, terminal 1.
Does the test light illuminate?–Go to Step 8Go to Step 9
8Repair the short to voltage in the injector driver cir-
cuit.
Is the repair complete?–Go to Step 10–

ENGINE CONTROLS 1F – 417
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0204
INJECTOR 4 CIRCUIT FAULT
Circuit Description
The Engine Control Module (ECM) has four individual in-
jector driver circuits, each of which controls an injector.
When a driver circuit is grounded by the ECM, the injector
is activated. The ECM monitors the current in each driver
circuit. The ECM measures a voltage drop through a fixed
resistor and controls it. The voltage on each driver is moni-
tored to detect a fault. If the voltage is not what the ECM
expects to monitor on the circuit, a Diagnostic Trouble
Code (DTC) is set. This DTC detects a short to ground
and/or an open circuit and short to battery conditions for
low–side drive injector outputs.
Conditions for Setting the DTC
S Monitor fault feedback signal from FETS.
S Engine is in run mode.
S Battery voltage is greater than 9 volts.
S Engine speed is greater than 700 rpm.
S Fault is present for more than 5 seconds.
Action Taken When the DTC Sets
S The ECM will illuminate the Malfunction Indicator
Lamp (MIL) the first time the fault is Detected.S The ECM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC
S The ECM will turn off the MIL on the third consecu-
tive trip cycle in which the diagnostic has been run
and the fault is no longer present.
S A history DTC will clear after 40 consecutive warm–
up cycles without a fault.
S DTC can be cleared by using the scan tool Clear
Info function.
S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
An injector 4 driver circuit that is open or shorted to voltage
will cause a DTC P0204 to set. It will also cause a misfire
due to an inoperative injector. A misfire DTC should also
be set indicating which injector is inoperative.
Long–term and short–term fuel trims that are excessively
high or low are a good indication that an injector is mal-
functioning. Refer to ”Fuel injector Balance Test” in this
section to check for malfunctioning injectors.

1F – 418IENGINE CONTROLS
DAEWOO V–121 BL4
The injector resistance tested at the ECM connection is
slightly more than if tested directly at the injector because
it includes resistance of the harness wires. The normal val-
ue is about 13.5 Ω.
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. Thiscreates an electronic copy of the data taken when
the malfunction occurred. The information is then
stored on the scan tool for later reference.
3. This step determines if DTC P0204 is the result of
a hard failure or an intermittent condition.
5. This step tests the wiring harness and ECM control
of the injectors using a test light.
7. This step determines if the circuitry is shorted to
voltage or the ECM is faulty.
9. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
DTC P0204 – Injector 4 Circuit Fault
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”
2Will the engine start?–Go to Step 3Go to
”Engine Cranks
But Will Not
Run”
31. Install a scan tool to the Data Link Connector
(DLC).
2. Turn the ignition ON, with the engine OFF.
3. Clear the Diagnostic Trouble Codes (DTCs)
using a scan tool.
4. Start the engine and idle for one minute.
Does DTC P0204 reset?–Go to Step 5Go to Step 4
41. Turn the ignition ON, with the engine OFF.
2. Review the Freeze Frame data and note the
parameters.
3. Operate the vehicle within the Freeze Frame
conditions as noted.
Does DTC P0204 reset?–Go to Step 5Go to
”Diagnostic
Aids”
51. Turn the ignition OFF.
2. Disconnect the Engine Control Module (ECM)
connector for injector 4.
3. Turn the ignition ON, with the engine OFF.
4. With a test light connected to ground, probe
the driver circuit, terminal M11.
Does the test light illuminate?–Go to Step 7Go to Step 6
6Repair the short to ground or open in the injector
driver circuit.
Is the repair complete?–Go to Step 10–
71. Disconnect the injector 4 wiring connection.
2. With a test light connected to ground, probe
the driver circuit, terminal 1.
Does the test light illuminate?–Go to Step 8Go to Step 9
8Repair the short to voltage in the injector driver cir-
cuit.
Is the repair complete?–Go to Step 10–