
1F–256 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F310
DIAGNOSTIC TROUBLE CODE (DTC) – P1538 A/C COMPRESSOR RELAY LOW
V O LTA G E
Circuit Description
The A/C system uses an A/C refrigerant pressure sen-
sor mounted in the high pressure side of the A/C refrig-
erant system to monitor A/C refrigerant pressure. The
engine control module (ECM) uses this information to
turn ON the engine coolant fans when the A/C refriger-
ant pressure is high and to keep the compressor disen-
gaged when A/C refrigerant pressure is excessively high
or low.
Conditions for Setting the DTC
A/C compressor relay circuit short to ground or open.
Action Taken When the DTC Sets
The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
The ECM will store conditions which were present
when the DTC was set as Failure Records data only.
This information will not be stored in the Freeze
Frame data.Conditions for Clearing the MIL/DTC
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
Inspect harness connectors for backed-out terminals,
improper mating, broken locks, improperly formed or
damaged terminals, and poor terminal-to-wire connec-
tion at the ECM.
Inspect the wiring harness for damage. If the harness
appears to be OK, observe the A/C pressure display on
the scan tool while moving the connectors and wiring
harnesses related to the ACP sensor. A change in the
A/C pressure display will indicate the location of the
fault.
If DTC P1538 cannot be duplicated, reviewing the Fail
Records 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 diag-
nosing the condition.

ENGINE CONTROLS 1F–257
DAEWOO M-150 BL2
DTC P1538 – A/C Compressor Relay Low Voltage
StepActionValue(s)YesNo
1
Perform an 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.
2. Disconnect the A/C compressor relay.
3. Measure the resistance between A/C compressor
relay terminals 85 and 86.
Does the resistance within the specified value?
0ΩGo to Step 3Go to Step 7
3
1. Turn the ignition switch to LOCK.
2. With the test light, connected to ground, probe
the ignition feed circuit, at terminal 86 in the relay
harness connector.
Does the test light illuminate?
–
Go to Step 5Go to Step 4
4
Repair a short to ground between the ignition switch
terminal 4 and A/C compressor relay terminal 86.
Is the repair complete?
–
Go to Step 9
–
5
1. 1. Turn the ignition switch to LOCK.
2. Disconnect the ECM.
3. With the test light, connected to ground, probe
the ignition feed circuit, at terminal 86 in the relay
harness connector.
Does the test light illuminate?
–
Go to Step 8Go to Step 6
6
Repair a short to ground between the ECM wiring
connector terminal 38 and A/C compressor relay
terminal 85.
Is the repair complete?
–
Go to Step 9
–
7Replace the A/C compressor relay.
Is the replacement complete?–Go to Step 9–
8
1. Turn the ignition switch to LOCK.
2. Replace the ECM.
Is the repair complete?
–
Go to Step 9
–
9
1. 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 10Go to Step 2
10
Check if any additional DTCs are set.
Are any DTCs displayed that that have not been
diagnosed?
–
Go to
applicable DTC
table
System OK

ENGINE CONTROLS 1F–259
DAEWOO M-150 BL2
DTC P0562 – System Voltage (Engine Side) Too Low
StepActionValue(s)YesNo
1
Perform an On-Board Diagnostic (EOBD) System
Check.
Is the system check complete?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2
1. Install a scan tool and clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine and raise the engine speed to
the specified value.
3. Load the electrical system by turning on the
headlights, high blower motor, etc.
Is the ignition voltage less than the specified value?
1,400rpm 10VGo to Step 3Go to Step 8
3
1. With the engine still running at the specified
value.
2. Using a digital voltmeter(DVM), measure the
battery voltage at the battery.
Is the battery voltage greater than the specified
value?
1,400rpm 12VGo to Step 4
Go to
“Diagnostic
Aids”
4
1. Turn the ignition switch to LOCK.
2. Disconnect the engine control module(ECM)
connector at the ECM.
3. Turn the Turn the ignition switch to ON with the
engine OFF.
4 Using a DVM, measure the ignition voltage at the
ignition feed circuit, terminal 29.
Is the ignition voltage greater than the specified
value?
10VGo to Step 5Go to Step 6
5
Check for a malfunctioning connection at the ECM
harness terminals and repair as necessary.
Is a repair necessary?
–
Go to Step 8Go to Step 7
6
Repair the poor connection (high resistance) in the
ignition feed circuit.
Is the repair complete?
–
Go to Step 8
–
7Replace the ECM.
Is the replacement complete?–Go to Step 8–
8
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 9Go to Step 2
9
Check if any additional DTCs are set.
Are any DTCs displayed that have not been
diagnosed?
–
Go to
applicable DTC
table
System OK

ENGINE CONTROLS 1F–261
DAEWOO M-150 BL2
DTC P0563 – System Voltage (Engine Side) Too High
StepActionValue(s)YesNo
1
Perform an On-Board Diagnostic (EOBD) System
Check.
Is the system check complete?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2
1. Install a scan tool and clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine and raise the engine speed to
the specified value.
3. Load the electrical system by turning on the
headlights, high blower motor, etc.
Is the ignition voltage less than the specified value?
1,400rpm 10VGo to Step 3Go to Step 8
3
1. With the engine still running at the specified
value.
2. Using a digital voltmeter(DVM), measure the
battery voltage at the battery.
Is the battery voltage greater than the specified
value?
1,400rpm 12VGo to Step 4
Go to
“Diagnostic
Aids”
4
1. Turn the ignition switch to LOCK.
2. Disconnect the engine control module(ECM)
connector at the ECM.
3. Turn the Turn the ignition switch to ON with the
engine OFF.
4. Using a DVM, measure the ignition voltage at the
ignition feed circuit, terminal 29.
Is the ignition voltage greater than the specified
value?
10VGo to Step 5Go to Step 6
5
Check for a malfunctioning connection at the ECM
harness terminals and repair as necessary.
Is a repair necessary?
–
Go to Step 8Go to Step 7
6
Repair the poor connection (high resistance) in the
ignition feed circuit.
Is the repair complete?
–
Go to Step 8
–
7Replace the ECM.
Is the replacement complete?–Go to Step 8–
8
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 9Go to Step 2
9
Check if any additional DTCs are set.
Are any DTCs displayed that have not been
diagnosed?
–
Go to
applicable DTC
table
System OK

1F–262 ENGINE CONTROLS
DAEWOO M-150 BL2
DIAGNOSTIC TROUBLE CODE (DTC) – P0601 ENGINE CONTROL MODULE
CHECKSUM ERROR
Circuit Description
The engine control module (ECM) is the control center
of the fuel injection system. It constantly looks at the in-
formation from various sensors, and controls the sys-
tems that after vehicle performance. The ECM also
performs the diagnostic function of the system. It can
recognize operational problems, alert the driver through
the Malfunction Indicator Lamp (MIL), and store a Diag-
nostic Trouble Code (DTC) or DTCs which identify the
problem areas to aid the technician in making repairs.
An electrically erasable programmable read only
memory (EEPROM) is used to house the program infor-
mation and the calibrations required for engine, trans-
axle, transaxle diagnostics operation. The ECM uses a
value called a checksum for error detection of the soft-
ware. The checksum is a value that is equal to all the
numbers in the software added together. The ECM adds
all the values in the software and if that value does notequal the checksum value, a checksum error is indi-
cated.
Conditions for Setting the DTC
The ECM detects more than 3 incorrect checksum.
Action Taken When the DTC Sets
The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
The ECM will store conditions which were present
when the DTC was set as Failure Records data only.
This information will not be stored in the Freeze
Frame data.
Conditions for Clearing the MIL/DTC
A history DTC will clear after 40 consecutive warm-up
cycles without a fault.
DTC(s) can be cleared by using the scan tool.
DTC P0601– Engine Control Module Checksum Error
StepActionValue(s)YesNo
1
Perform an On-Board Diagnostic (EOBD) System
Check.
Is the system check complete?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2Replace the engine control module(ECM).
Is the replacement complete?–Go to Step 3–
3
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 4Go to Step 2
4
Check if any additional DTCs are set.
Are any DTCs displayed that have not been
diagnosed?
–
Go to
applicable DTC
table
System OK

ENGINE CONTROLS 1F–263
DAEWOO M-150 BL2
DIAGNOSTIC TROUBLE CODE (DTC) – P0604 ENGINE CONTROL MODULE
INTERNAL/EXTERNAL RAM ERROR
Circuit Description
The engine control module (ECM) is the control center
of the fuel injection system. It constantly looks at the in-
formation from various sensors, and controls the sys-
tems that after vehicle performance. The ECM also
performs the diagnostic function of the system. It can
recognize operational problems, alert the driver through
the Malfunction Indicator Lamp (MIL), and store a Diag-
nostic Trouble Code (DTC) or DTCs which identify the
problem areas to aid the technician in making repairs.
An electrically erasable programmable read only
memory (EEPROM) is used to house the program infor-
mation and the calibrations required for engine, trans-
axle, transaxle diagnostics operation. The ECM uses a
value called a checksum for error detection of the soft-
ware. The checksum is a value that is equal to all the
numbers in the software added together. The ECM adds
all the values in the software and if that value does not
equal the checksum value, a checksum error is indi-
cated.Conditions for Setting the DTC
The ECM detects more than 3 incorrect checksum.
Action taken when The DTCs 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 Failure Records buffers.
A history DTC is stored.
Coolant fan turns on.
Conditions for Clearing the MIL/DTC
The MIL will turn off after four 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.
DTC P0604 – Engine Control Module RAM Error
StepActionValue(s)YesNo
1
Perform an On-Board Diagnostic (EOBD) System
Check.
Is the system check complete?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2Replace the engine control module(ECM).
Is the replacement complete?–Go to Step 3–
3
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 4Go to Step 2
4
Check if any additional DTCs are set.
Are any DTCs displayed that have not been
diagnosed?
–
Go to
applicable DTC
table
System OK

1F–264 ENGINE CONTROLS
DAEWOO M-150 BL2
DIAGNOSTIC TROUBLE CODE (DTC) – P0605 ENGINE CONTROL MODULE
NMVY WRITE ERROR
Circuit Description
The engine control module (ECM) is the control center of
the fuel injection system. It constantly looks at the infor-
mation from various sensors, and controls the systems
that after vehicle performance. The ECM also performs
the diagnostic function of the system. It can recognize op-
erational problems, alert the driver through the Malfunc-
tion Indicator Lamp (MIL), and store a Diagnostic Trouble
Code (DTC) or DTCs which identify the problem areas to
aid the technician in making repairs. An electrically eras-
able programmable read only memory (EEPROM) is
used to house the program information and the calibra-
tions required for engine, transaxle, transaxle diagnos-
tics operation. The ECM uses a value called a checksum
for error detection of the software. The checksum is a val-
ue that is equal to all the numbers in the software added
together. The ECM adds all the values in the software
and if that value does not equal the checksum value, a
checksum error is indicated.Conditions for Setting the DTC
The ECM detects more than 3 incorrect checksum.
Action taken when The DTCs 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 Failure Records buffers.
A history DTC is stored.
Coolant fan turns on.
Conditions for Clearing the MIL/DTC
The MIL will turn off after four 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.
DTC P0605 Engine Control Module NMVY Write Error
StepActionValue(s)YesNo
1
Perform an On-Board Diagnostic (EOBD) System
Check.
Is the system check complete?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2Replace the engine control module(ECM).
Is the replacement complete?–Go to Step 3–
3
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 4Go to Step 2
4
Check if any additional DTCs are set.
Are any DTCs displayed that have not been
diagnosed?
–
Go to
applicable DTC
table
System OK

1F–266 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F050
DIAGNOSTIC TROUBLE CODE (DTC) – P1610 MAIN RELAY HIGH VOLTAGE
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
This DTC can be stored in “key-on” status.
Main relay wiring harness high voltage.
Action Taken When The DTCs 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 failure records buffers.
A history DTC is stored.
Conditions for Clearing the MIL/DTC
The MIL will turn off after four 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.
Using the scan tool can clear DTC(s).
Diagnostic Aids
Inspect harness connectors for backed-out terminals,
improper mating, broken locks, improperly formed or
damaged terminals, and poor terminal-to-wire connec-
tion at the ECM.
Inspect the wiring harness for damage. If the harness
appears to be OK, observe the A/C pressure display on
the scan tool while moving the connectors and wiring
harnesses related to the ACP sensor. A change in the
A/C pressure display will indicate the location of the
fault.
If DTC P1610 cannot be duplicated, reviewing the Fail
Records 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 diag-
nosing the condition.