DAEWOO NUBIRA 2004 Service Repair Manual

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–

1F – 416IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
91. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 10–
101. Using the scan tool, clear the 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
11Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to applica-
ble DTC tableSystem OK

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–

ENGINE CONTROLS 1F – 419
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
91. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 10–
101. Using the scan tool, clear the 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
11Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to applica-
ble DTC tableSystem OK

1F – 420IENGINE CONTROLS
DAEWOO V–121 BL4

ENGINE CONTROLS 1F – 421
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0300
MULTIPLE CYLINDER MISFIRE DETECTED
System Description
The Engine Control Module (ECM) monitors the crank-
shaft and camshaft positions to detect if the engine is mis-
firing. The ECM looks for a quick drop in crankshaft speed.
This test is executed in blocks of 100 engine revolution
tests. It may take between one to several tests to store a
Diagnostic Trouble Code (DTC) and illuminate the Mal-
function Indicator Lamp (MIL). Under light misfire condi-
tions, it may also take more than one trip to set a DTC. Se-
vere misfire will flash the MIL, indicating that catalyst
damage is possible.
Conditions for Setting the DTC
S Emission threshold is 3%.
S 20 engine cycles have occurred since cranking has
started.
S A/C compressor clutch has not just engaged or dis-
engaged.
S Engine load and engine speed is in a detectable
region and is at or above zero torque.
S Camshaft Position (CMP) sensor is in synchroniza-
tion.
S Exhaust Gas Recirculation (EGR) flow diagnostic is
not in progress.
S Fuel level is greater than 12% of rated tank capac-
ity.
S Decel Fuel Cutoff (DFCO) not active.
S Throttle position change is less than 3% per 125
ms.
S Vehicle has not encountered an abusive engine
speed of 7000 rpm.
S Crankshaft speed patters are normal.
S Throttle position is less than 3% when vehicle
speed is greater than 10 km/h (6 mph).
S Vehicle voltage is between 11 and 16 volts.
S Engine Coolant Temperature (ECT) is between
–7°C (19°F) and 120°C (248°F).
S There is the correct ratio between Crankshaft Posi-
tion (CKP) sensor pulses and CMP sensor pulses.
S DTCs P0106, P0107, P0108, P0117, P0118,
P0122, P0123, P0336, P0337, P0341, P0342 and
P0502 are not set.
Action Taken When the DTC Sets
S The MIL will illuminate after two consecutive ignition
cycles in which the diagnostic runs with the fault
active.
Or
S The MIL will illuminate immediately and flash if mis-
fire is present.
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
within the freeze frame conditions that the DTC
failed.
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 can also be the result of a defective reluctor
wheel. Remove the CKP sensor and inspect the reluctor
wheel through the sensor mount hole. Check for porosity
and the condition of wheel. If the DTC is intermittent refer
to ”Symptoms Diagnosis” in this section.
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.
3. A visual/physical inspection should include check-
ing the following components:
S The wiring for proper connections, pinches or
cuts.
S The ECM grounds for being clean and tight.
S The vacuum hoses for splits, kinks, and proper
connections as shown on the Vehicle Emission
Information label. Check thoroughly for any type
of leak or restriction.
S For air leaks at the throttle body mounting area
and intake manifold sealing surfaces.
5. When all the accumulators are relatively equal, then
the misfire is being caused by something that af-
fects the entire engine. When they are not then the
misfire is being caused by something that is specif-
ic to two or more cylinders.
6. Whenever the misfire is not present operating the
vehicle may be necessary to duplicate the condi-
tions in the Freeze Frame Data in order to detect
misfire. Depending on the engine load, the condi-
tions may have to be maintained for up to 20 sec-
onds. Whenever the misfire accumulators start to
increment, then misfire is present. A history misfire
counter will store the number of misfires that have
occurred until the DTC is cleared.

1F – 422IENGINE CONTROLS
DAEWOO V–121 BL4
8. Check fuel for water, alcohol, etc.
9. A basic engine problem that affects all cylinders is
the only possibility at this point. (Cam timing,
throttle body leak, restricted air flow, etc.)
11. Tests the ignition system voltage output using a
spark tester.
12. Replace any spark plugs that are worn, cracked or
fouled.
13. Checks for voltage at the ignition feed circuit.
18. Whenever the driver circuit is shorted to ground,
the light will be on steady. When the driver circuit is
shorted to voltage or open, the light will be off.19. Since voltage is supplied to the fuel injector on a
single circuit, the malfunction could only be a poor
connection or open in the fuel injector harness. An
open before the harness would result in an ”Engine
Cranks But Will Not Run” complaint.
28. Before replacing the ECM, check terminals for im-
proper mating, broken locks, or physical damage to
the wiring harness. The replacement ECM must be
reprogrammed. Refer to the latest Techline proce-
dure for ECM reprogramming.
DTC P0300 – Multiple Cylinder Misfire Detected
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, with the engine OFF.
3. Request Diagnostic Trouble Codes (DTCs)
Are DTCs P0201, P0202, P0203, P0204 set?–Go to applica-
ble DTCGo to Step 3
31. Perform a visual/physical inspection.
2. Make any repairs that are necessary.
Is the repair complete?–Go to Step 27Go to Step 4
4Start the engine and allow it to idle.
Are any Misfire Current counters incrementing?–Go to Step 5Go to Step 6
5Are all counters equal (within a percentage of each
other)?–Go to Step 7Go to Step 11
61. 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 and conditions for setting this DTC
as noted.
Are any Misfire Current counters incrementing?–Go to Step 5Go to
”Diagnostic
Aids”
71. Turn the engine OFF.
2. Install a fuel pressure gauge to the fuel rail.
3. Observe the fuel pressure with the engine run-
ning.
Is the fuel pressure within the specified value?284–325 kPa
(41–47 psi)Go to Step 8Go to
”Fuel System
Diagnosis”
8Check the fuel for contamination.
Is the fuel OK?–Go to Step 9Go to Step 10
9Check for a basic engine problem and repair as nec-
essary.
Is the repair complete?–Go to Step 27–
10Replace the contaminated fuel.
Is the repair complete?–Go to Step 27–

ENGINE CONTROLS 1F – 423
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
111. Turn the engine OFF.
2. Disconnect the fuel injector harness connector.
3. Install a spark tester on cylinder #1 spark plug
cable.
4. Crank the engine and check for spark.
5. Repeat the above procedure on cylinders #2,
#3 and #4.
Is a spark observed on all four spark plug cables?–Go to Step 12Go to Step 20
12Replace any malfunctioning spark plugs if neces-
sary.
Is the repair complete?–Go to Step 27Go to Step 13
131. Turn the engine OFF.
2. Disconnect the fuel injector connectors from
the injectors.
3. Install an injector test light on the injector har-
ness connector for the cylinders that had mis-
fired.
4. Crank the engine and note the test light.
Does the injector test light blink?–Go to Step 14Go to Step 15
14Perform the Fuel Injector Balance Test.
Are the fuel injectors OK?–Go to Step 9Go to Step 16
151. Disconnect the injector test light.
2. With a test light connected to ground, probe
the ignition feed terminal 2 of the injector har-
ness connector for each cylinder that had mis-
fire.
3. Crank the engine.
Does the test light illuminate?–Go to Step 17Go to Step 19
16Replace any malfunctioning fuel injectors.
Is the repair complete?Go to Step 27–
17Check the affected fuel injector driver circuit at termi-
nals M25, M22, M24, and M11 for an open, short, or
short to voltage.
Is a problem found?–Go to Step 18Go to Step 24
18Repair the open or the shorted fuel injector driver cir-
cuit.
Is the repair complete?–Go to Step 26–
19Repair the open ignition feed circuit between the fuel
injector harness connector and the fuel injector con-
nector.
Is the repair complete?–Go to Step 27–
20Measure the resistance of the spark plug cable that
the spark plug tester did not spark.
Is the resistance of the spark plug cable less than the
specified value?30,000 WGo to Step 21Go to Step 25
21Inspect the Engine Control Module (ECM) connec-
tor and connections.
Are the connections OK?–Go to Step 22Go to Step 23
22Check the affected cylinders ignition control circuit
for an open or short and repair as necessary.
Is the repair complete?–Go to Step 27Go to Step 26

1F – 424IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
23Repair the connector or connections.
Is the repair complete?–Go to Step 27–
241. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 27–
25Replace the spark plug cable.
Is the repair complete?–Go to Step 27–
26Replace the faulty ignition coil.
Is the repair complete?–Go to Step 27Go to Step 24
271. Using the scan tool, clear the DTCs.
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the conditions for
setting this DTC as supported in the text.
Does the scan tool indicate that this diagnostic ran
and passed?–Go to Step 28Go to Step 2
28Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK