Page 217 of 1184

ENGINE CONTROLS 1F–11 9
DAEWOO M-150 BL2
DTC P1231 – Fuel Pump Relay High Voltage
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Is the system check complete?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2
1. Turn the ignition switch to LOCK for 10 seconds.
2. Turn the Turn the ignition switch to ON.
3. Listen for in-tank fuel pump operation.
Does the fuel pump operate?
2.55 seconds
Go to
“Diagnostic
Aids”
Go to Step 3
3
Check for short to battery voltage or low voltage in
the wire between the fuel pump relay connector
terminal 87 and fuel pump connector 3.
Is the problem found?
–
Go to Step 7Go to Step 5
4
1. Repair the wire between the fuel pump relay
connector terminal 87 and fuel pump connector
terminal 3.
2. Install the fuel pump relay.
3. Turn the engine OFF for 10 seconds.
4. Clear any DTCs from ECM.
5. Turn the ignition switch to ON.
Does the fuel pump operate?
2.55 secondsGo to Step 14
–
5
1. Replace the fuel pump relay.
2. Turn the ignition OFF for 10 seconds.
3. Clear any DTCs from ECM.
4. Turn the Turn the ignition switch to ON.
Does the fuel pump operate?
2.55 secondsGo to Step 11Go to Step 6
6
Check for short to battery voltage wire between the
fuel pump relay connector terminal 66 and the
ignition after key ON 1(IGN 1).
Is the problem found?
–
Go to Step 8Go to Step 7
7
Check for an open wire between the fuel pump relay
connector terminal 85 and the ECM connector
terminal 10.
Is the problem found?
–
Go to Step 9Go to Step 10
8
1. Repair the wire between the fuel pump relay
connector terminal 66 and the ignition key ON
(IGN1).
2. Install the fuel pump relay.
3. Turn the ignition OFF for 10 seconds.
4. Clear any DTCs from ECM.
5. Turn the ignition switch to ON.
Does the fuel pump operate?
2.55 secondsSystem OKGo to Step 13
9
1. Repair the wire between the fuel pump relay
connector terminal 85 and the ECM connector
terminal 10.
2. Install the fuel pump relay.
3. Turn the ignition OFF for 10 seconds.
4. Clear any DTCs from ECM.
5. Turn the ignition switch to ON.
Does the fuel pump operate?
2.55 secondsSystem OKGo to Step 10
Page 218 of 1184
1F–120 ENGINE CONTROLS
DAEWOO M-150 BL2
DTC P1231 – Fuel Pump Relay High Voltage (Cont’d)
StepActionValue(s)YesNo
10
1. Replace the ECM.
2. Turn the ignition OFF for 10 seconds.
3. Clear any DTCs from ECM.
4. Turn the ignition switch to ON.
Does the fuel pump operate?
2.55 secondsSystem OKGo to Step 11
11
1. 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 ad specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?
–
Go to Step 12Go to Step 2
12
Check if any additional DTCs are set.
Are any DTCs displayed that have not been
diagnosed?
–
Go to
applicable DTC
table
System OK
Page 219 of 1184
ENGINE CONTROLS 1F–121
DAEWOO M-150 BL2
BLANK
Page 220 of 1184

1F–122 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F150
DIAGNOSTIC TROUBLE CODE (DTC) – P0261 INJECTOR 1 LOW VOLTAGE
Circuit Description
The engine control module (ECM) has three individual
injector driver circuits, each of which controls an injector.
When a driver circuit is grounded by the ECM, the injec-
tor 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 monitored 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 low voltage and/or an open circuit and high voltage
conditions for low-side drive injector outputs.
Conditions for Setting the DTC
This DTC can be stored in “key-on” status.
The injector voltage does not equal the ignition volt-
age when the injector is commanded OFF, or the in-
jector voltage does not equal 0 volts when the injector
is commanded ON.
The battery voltage is less than 9 volts.
The above conditions are met for 5seconds.
Action Taken when the DTC Sets
The Malfunction Indicator Lamp (MIL) will illuminate.The ECM will record operating conditions at the time
the diagnostic fails. This information will be stored in
the Freeze Frame and Records buffers.
A history DTC is stored.
Conditions for Clearing the MIL/DTC
The MIL will turn off after 4 consecutive ignition
cycles in which the diagnostic runs without a fault.
A history DTC will clear after 40 consecutive warm up
cycles without a fault.
DTC(s) can be cleared by using the scan tool.
DIAGNOSTIC AIDS
An injector 4river circuit that is open or shorted to volt-
age will causes a DTC P0261 to set. It will also cause a
misfire due to an inoperative injector. A misfire DTC
should also be set indicating which injector is inopera-
tive.
Long-term and short-terms fuel trims that are excessive-
ly high or low are a good indication that an injector is
malfunctioning. Refer to “Fuel Injector 2alance Test” in
this Section to check for malfunctioning injectors.
The injector resistance tested at the ECM connection is
slightly more than it tested directly at the injector
2ecause it includes resistance of the harness wires. The
normal value is about 13.5Ω.
Page 221 of 1184

ENGINE CONTROLS 1F–123
DAEWOO M-150 BL2
DTC P0261 – Injector 1 Low Voltage
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Is the system check complete?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2
With the engine start?
–
Go to Step 3
Go to
“Engine Crank
but will not
Run”
3
1. Install a scan tool and clear the Diagnostic
Trouble Codes (DTCs).
2. Idle the engine for one minuet.
Does DTC P0261 reset?
–
Go to Step 5Go to Step 4
4
1. Review the Freeze Frame data with the ignition
ON and the engine OFF and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions as notes.
Does DTC P0261 reset?
–
Go to Step 5
Go to
“Diagnostic
Aids”
5
1. Turn the ignition switch to LOCK.
2. Check for short to ground in the wire between the
injector 1 connector terminal 1 and ECM
connector terminal 90.
Is the problem found?
–
Go to Step 7Go to Step 6
6
1. Turn the ignition switch to LOCK.
2. Check for short to ground in the wire between the
injector 1 connector terminal 2 and battery
positive.
Is the problem found?
–
Go to Step 7Go to Step 8
7
1. Repair the wire or the connector terminal as
needed.
2. Clear any DTCs from ECM.
3. Perform the Diagnostic System Check.
Is the repair complete?
–
System OK
–
8
1. Replace the injector valve.
2. Clear any DTCs from ECM.
3. Perform the Diagnostic System Check.
Is the repair complete?
–
Go to Step 9System OK
9
1. Turn the ignition switch to LOCK.
2. Replace the ECM.
3. Perform the Diagnostic System Check.
Does DTC P0261 reset?
–
Go to Step 10
–
10
Check if any additional DTCs are set.
Are any DTCs displaced that have not been
diagnosed?
–
Go to
applicable DTC
table
System OK
Page 222 of 1184

1F–124 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F150
DIAGNOSTIC TROUBLE CODE (DTC) – P0262 INJECTOR 1 HIGH VOLTAGE
Circuit Description
The engine control module (ECM) has three individual
injector driver circuits, each of which controls an injector.
When a driver circuit is grounded by the ECM, the injec-
tor 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 monitored 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 low voltage and/or an open circuit and high voltage
conditions for low-side drive injector outputs.
Conditions for Setting the DTC
This DTC can be stored in “key-on” status.
The injector voltage does not equal the ignition volt-
age when the injector is commanded OFF, or the in-
jector voltage does not equal 0 volts when the injector
is commanded ON.
The battery voltage is more than 16 volts.
The above conditions are met for 5seconds.
Action Taken when the DTC Sets
The Malfunction Indicator Lamp (MIL) will illuminate.The ECM will record operating conditions at the time
the diagnostic fails. This information will be stored in
the Freeze Frame and Records buffers.
A history DTC is stored.
Conditions for Clearing the MIL/DTC
The MIL will turn off after 4 consecutive ignition
cycles in which the diagnostic runs without a fault.
A history DTC will clear after 40 consecutive warm up
cycles without a fault.
DTC(s) can be cleared by using the scan tool.
DIAGNOSTIC AIDS
An injector 4river circuit that is open or shorted to volt-
age will causes a DTC P0262 to set. It will also cause a
misfire due to an inoperative injector. A misfire DTC
should also be set indicating which injector is inopera-
tive.
Long-term and short-terms fuel trims that are excessive-
ly high or low are a good indication that an injector is
malfunctioning. Refer to “Fuel Injector 2alance Test” in
this Section to check for malfunctioning injectors.
The injector resistance tested at the ECM connection is
slightly more than it tested directly at the injector
2ecause it includes resistance of the harness wires. The
normal value is about 13.5Ω.
Page 223 of 1184

ENGINE CONTROLS 1F–125
DAEWOO M-150 BL2
DTC P0262 – Injector 1 High Voltage
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Is the system check complete?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2
With the engine start?
–
Go to Step 3
Go to
“Engine Crank
but will not
Run”
3
1. Install a scan tool and clear the Diagnostic
Trouble Codes (DTCs).
2. Idle the engine for one minuet.
Does DTC P0262 reset?
–
Go to Step 5Go to Step 4
4
1. Review the Freeze Frame data with the ignition
ON and the engine OFF and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions as notes
Does DTC P0262 reset?
–
Go to Step 5
Go to
“Diagnostic
Aids”
5
1. Turn the ignition switch to Lock.
2. Check for an open or short to battery voltage in
the wire between the injector 1 connector terminal
1 and ECM connector terminal 90.
Is the problem found?
–
Go to Step 7Go to Step 6
6
1. Turn the ignition switch to Lock.
2. Check for short to battery voltage in the wire
between the injector 1 connector terminal 2 and
battery positive.
Is the problem found?
–
Go to Step 7Go to Step 8
7
1. Repair the wire or the connector terminal as
needed.
2. Clear any DTCs from ECM.
3. Perform the Diagnostic System Check.
Is the repair complete?
–
System OK
–
8
1. Replace the injector valve
2. Clear any DTCs from ECM.
3. Perform the Diagnostic System Check.
Does DTC P0262 reset?
–
Go to Step 9System OK
9
1. Turn the ignition switch to LOCK.
2. Replace the ECM.
3. Perform the Diagnostic System Check.
Is the repair complete?
–
Go to Step 10
–
10
Check if any additional DTCs are set.
Are any DTCs displaced that have not been
diagnosed?
–
Go to
applicable DTC
table
System OK
Page 224 of 1184

1F–126 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F150
DIAGNOSTIC TROUBLE CODE (DTC) – P0264 INJECTOR 2 LOW VOLTAGE
Circuit Description
The engine control module (ECM) has three individual
injector driver circuits, each of which controls an injector.
When a driver circuit is grounded by the ECM, the injec-
tor 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 monitored 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 low voltage and/or an open circuit and high voltage
conditions for low-side drive injector outputs.
Conditions for Setting the DTC
This DTC can be stored in “key-on” status.
The injector voltage does not equal the ignition volt-
age when the injector is commanded OFF, or the in-
jector voltage does not equal 0 volts when the injector
is commanded ON.
The battery voltage is less than 9 volts.
The above conditions are met for 5 seconds.
Action Taken when the DTC Sets
The Malfunction Indicator Lamp (MIL) will illuminate.The ECM will record operating conditions at the time
the diagnostic fails. This information will be stored in
the Freeze Frame and Records buffers.
A history DTC is stored.
Conditions for Clearing the MIL/DTC
The MIL will turn off after 4 consecutive ignition
cycles in which the diagnostic runs without a fault.
A history DTC will clear after 40 consecutive warm up
cycles without a fault.
DTC(s) can be cleared by using the scan tool.
DIAGNOSTIC AIDS
An injector 4river circuit that is open or shorted to volt-
age will causes a DTC P0264 to set. It will also cause a
misfire due to an inoperative injector. A misfire DTC
should also be set indicating which injector is inopera-
tive.
Long-term and short-terms fuel trims that are excessive-
ly high or low are a good indication that an injector is
malfunctioning. Refer to “Fuel Injector 2alance Test” in
this Section to check for malfunctioning injectors.
The injector resistance tested at the ECM connection is
slightly more than it tested directly at the injector
2ecause it includes resistance of the harness wires. The
normal value is about 13.5Ω.