2004 DAEWOO NUBIRA relay

1F – 292IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1231
FUEL PUMP RELAY HIGH VOLTAGE (1.6L DOHC)
Circuit Description
When the ignition switch is turned ON, the ECM will acti-
vate the fuel pump relay and run the in–tank fuel pump.
The fuel pump will operate as long as the engine is crank-
ing or running and the ECM is receiving ignition reference
pulses.
Conditions for Setting the DTC
S This DTC can be stored in ”key–on” status.
S A high voltage condition exists.
Action Taken When the DTC 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 Records buffers.
S A history DTC is stored.
S Coolant fan turns ON.
Conditions for Clearing the MIL/DTCS The MIL will turn off after 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 DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for 10 sec-
onds.
Diagnostic Aids
An Intermittent problem may be caused by a poor connec-
tion, rubbed through wire insulation, or wire that is broken
inside the insulation.
Any circuitry, that is suspected as causing the complaint,
should be thoroughly checked for the following conditions.
S Backed–out terminals
S Improper mating
S Broken locks
S Improperly formed
S Damaged terminals
S Poor terminals to wire connection
S Physical damage to the wiring harness

ENGINE CONTROLS 1F – 293
DAEWOO V–121 BL4
DTC P1231 – Fuel Pump Relay High Voltage (1.6L DOHC)
StepActionValue(s)YesNo
1Perform an Euro 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 switch to LOCK for 10 sec-
onds.
2. Turn the Turn the ignition switch to ON.
3. Listen for in–tank fuel pump operation.
Does the fuel pump operate?2.55 secondsGo to
”Diagnostic
Aids”Go to Step 3
3Check for short to battery voltage or low voltage in
the wire between the fuel pump relay connector ter-
minal 87 and fuel pump connector 3.
Is the problem found?–Go to Step 7Go to Step 5
41. 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 11–
51. 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
6Check for short to battery voltage wire between the
fuel pump relay connector terminal 86 and the igni-
tion after key ON(IGN 1).
Is the problem found?–Go to Step 8Go to Step 7
7Check for an open wire between the fuel pump relay
connector terminal 85 and the ECM connector termi-
nal 6.
Is the problem found?–Go to Step 9Go to Step 10
81. Repair the wire between the fuel pump relay
connector terminal 86 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 10
91. Repair the wire between the fuel pump relay
connector terminal 85 and the ECM connector
terminal 6.
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

1F – 324IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1537
A/C COMPRESSOR RELAY HIGH VOLTAGE
Circuit Description
The A/C system uses an A/C refrigerant pressure sensor
mounted in the high pressure side of the A/C refrigerant
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 refrigerant pressure is
high and to keep the compressor disengaged when A/C
refrigerant pressure is excessively high or low.
The air conditioning pressure (ACP) sensor operates like
other 3–wire sensors. The ECM applies a 5.0 volt refer-
ence and a sensor ground to the sensor. Changes in the
A/C refrigerant pressure will causes the ACP sensor input
to the ECM to vary. The ECM monitors the ACP sensor
signal circuit and can determine when the signal is out of
the possible range of the sensor. When the signal is out of
range for a prolonged period of time, the ECM will not allow
the A/C compressor clutch to engage. This is done to pro-
tect the compressor.
Conditions for Setting the DTC
S The air conditioning compressor relay circuit is a
short to battery condition exists.
Action Taken When the DTC SetsS 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.
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.

ENGINE CONTROLS 1F – 325
DAEWOO V–121 BL4
If DTC P1537 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.
DTC P1537 – A/C Compressor Relay High Voltage
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 switch to LOCK.
2. Disconnect the A/C compressor relay.
3. Measure the resistance between A/C compres-
sor relay terminals 85 and 86.
Does the resistance within the specified value?0WGo to Step 3Go to Step 7
31. 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
4Repair a short to battery voltage between the ignition
switch terminal and A/C compressor relay terminal
86.
Is the repair complete?–Go to Step 9–
51. 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 85 in the
relay harness connector.
Does the test light illuminate?–Go to Step 8Go to Step 6
6Repair a short to battery voltage between the ECM
wiring connector terminal 41 and A/C compressor
relay terminal 86.
Is the repair complete?–Go to Step 9–
7Replace the A/C compressor relay.
Is the replacement complete?–Go to Step 9–
81. Turn the ignition switch to LOCK.
2. Replace the ECM.
Is the repair complete?–Go to Step 9–
91. 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
10Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
applicable DTC
tableSystem OK

1F – 326IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1538
A/C COMPRESSOR RELAY LOW VOLTAGE
Circuit Description
The A/C system uses an A/C refrigerant pressure sensor
mounted in the high pressure side of the A/C refrigerant
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 refrigerant pressure is
high and to keep the compressor disengaged when A/C
refrigerant pressure is excessively high or low.
The air conditioning pressure (ACP) sensor operates like
other 3–wire sensors. The ECM applies a 5.0 volt refer-
ence and a sensor ground to the sensor. Changes in the
A/C refrigerant pressure will causes the ACP sensor input
to the ECM to vary. The ECM monitors the ACP sensor
signal circuit and can determine when the signal is out of
the possible range of the sensor. When the signal is out of
range for a prolonged period of time, the ECM will not allow
the A/C compressor clutch to engage. This is done to pro-
tect the compressor.
Conditions for Setting the DTC
S The air conditioning compressor relay circuit is a
short to ground an open condition exists.
Action Taken When the DTC SetsS 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.
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.

ENGINE CONTROLS 1F – 327
DAEWOO V–121 BL4
If DTC P1538 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.
DTC P1538 – A/C Compressor Relay Low Voltage
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 switch to LOCK.
2. Disconnect the A/C compressor relay.
3. Measure the resistance between A/C compres-
sor relay terminals 85 and 86.
Does the resistance within the specified value?0WGo to Step 3Go to Step 7
31. 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
4Repair a short to ground between the ignition switch
and A/C compressor relay terminal 86.
Is the repair complete?–Go to Step 9–
51. 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
6Repair a short to ground between the ECM wiring
connector terminal 41 and A/C compressor relay ter-
minal 86.
Is the repair complete?–Go to Step 9–
7Replace the A/C compressor relay.
Is the replacement complete?–Go to Step 9–
81. Turn the ignition switch to LOCK.
2. Replace the ECM.
Is the repair complete?–Go to Step 9–
91. 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
10Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
applicable DTC
tableSystem OK

1F – 328IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1610
MAIN RELAY HIGH 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 battery 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 P1610 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.

ENGINE CONTROLS 1F – 329
DAEWOO V–121 BL4
DTC P1610 – Main Relay High 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