
ENGINE CONTROLS 1F – 255
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
41. Turn the ignition switch to LOCK.
2. Disconnect the relay.
3. Using a DVM, measure the resistance between
terminals 85 and 9 in the high speed cooling
fan relay control circuit in the ECM harness
connector to ground.
Does the DVM display infinite resistance?–Go to Step 12Go to Step 10
51. Turn the ignition switch to LOCK.
2. Disconnect the relay.
3. Connect a test light between the relay coil ter-
minals 86 and 85 in the relay harness connec-
tor.
4. Turn the Turn the ignition switch to ON.
5. Using the scan tool, command the relay ON
and OFF.
Does the test light turn ON and OFF with each com-
manded?–Go to Step 8Go to Step 6
6With the test light connected to ground, probe the
ignition feed circuit in the relay harness connector.
Does the test light illuminate?–Go to Step 7Go to Step 11
71. Turn the ignition switch to LOCK.
2. Reconnect the relay.
3. Disconnect the ECM connector containing the
relay control circuit.
4. Turn the Turn the ignition switch to ON.
5. With a fused jumper wire connected to ground,
probe the relay control circuit at terminal 9 in
the ECM harness connector.
Does the relay operate?–Go to Step 9Go to Step 10
8Check the connections at the relay.
Is a problem found and corrected?–Go to Step 14Go to Step 12
9Check the connection at the ECM.
Is a problem found and corrected?–Go to Step 11Go to Step 13
10Repair the faulty relay control circuit.
Is the repair complete?–Go to Step 14–
11Repair the faulty relay ignition feed circuit.
Is the repair complete?–Go to Step 14–
12Replace the relay.
Is the replacement complete?–Go to Step 14–
13Replace the ECM.
Is the replacement complete?–Go to Step 14–

ENGINE CONTROLS 1F – 265
DAEWOO V–121 BL4
DTC P0532 – A/C Pressure Sensor Low Voltage
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. Idle the engine.
Does the scan tool display Air Conditioning Pressure
(ACP) sensor voltage below the specified value?0.06 VGo to Step 3Go to Step 4
31. Turn the ignition OFF.
2. Disconnect the ACP sensor connector.
3. Jumper the ACP signal circuit, terminal 2 to the
5 volt reference circuit, terminal 1.
4. Turn the ignition switch on.
Does the ACP voltage read more than the specified
value?4.9 VGo to Step 5Go to Step 6
41. Turn the ignition ON, with the engine OFF.
2. Operate the vehicle within the Failure Record
conditions and Conditions For Setting the DTC
as noted.
Does the scan tool display ACP voltage below the
specified value?0.06 VGo to Step 3Go to
”Diagnostic
Aids”
5Inspect the ACP sensor harness connector termi-
nals for the following conditions:
S Poor connections
S Proper contact tension
S Poor terminal–to–wire connection
Is a problem found?–Go to Step 8Go to Step 9
61. Turn the ignition OFF.
2. Remove the jumper wire.
3. Probe the ACP sensor signal circuit terminal 2
with a test light to B+.
4. Turn the ignition ON.
Does the scan tool read over the specified value?4 VGo to Step 7Go to Step 11
7Check the ACP sensor 5 volt reference circuit for an
open or short to ground and repair as needed.
Is the repair complete?–Go to Step 13Go to Step 10
8Repair the connection terminals as necessary.
Is the repair complete?–Go to Step 13–
91. Turn the ignition OFF.
2. Replace the ACP sensor.
Is the repair complete?–Go to Step 13–
101. Turn the ignition OFF.
2. Replace the engine control module (ECM).
Is the repair complete?–Go to Step 13–

1F – 268IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P0533 – A/C Pressure Sensor High Voltage
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. Idle the engine.
Does the scan tool display Air Conditioning Pressure
(ACP) sensor voltage below the specified value?0.06 VGo to Step 3Go to Step 4
31. Turn the ignition OFF.
2. Disconnect the ACP sensor connector.
3. Jumper the ACP signal circuit, terminal 2 to the
5 volt reference circuit, terminal 1.
4. Turn the ignition switch on.
Does the ACP voltage read more than the specified
value?4.9 VGo to Step 5Go to Step 6
41. Turn the ignition ON, with the engine OFF.
2. Operate the vehicle within the Failure Record
conditions and Conditions For Setting the DTC
as noted.
Does the scan tool display ACP voltage below the
specified value?0.06 VGo to Step 3Go to
”Diagnostic
Aids”
5Inspect the ACP sensor harness connector termi-
nals for the following conditions:
S Poor connections
S Proper contact tension
S Poor terminal–to–wire connection
Is a problem found?–Go to Step 8Go to Step 9
61. Turn the ignition OFF.
2. Remove the jumper wire.
3. Probe the ACP sensor signal circuit terminal 2
with a test light to B+.
4. Turn the ignition ON.
Does the scan tool read over the specified value?4 VGo to Step 7Go to Step 11
7Check the ACP sensor 5 volt reference circuit for an
open or short to ground and repair as needed.
Is the repair complete?–Go to Step 13Go to Step 10
8Repair the connection terminals as necessary.
Is the repair complete?–Go to Step 13–
91. Turn the ignition OFF.
2. Replace the ACP sensor.
Is the repair complete?–Go to Step 13–
101. Turn the ignition OFF.
2. Replace the engine control module (ECM).
Is the repair complete?–Go to Step 13–

ENGINE CONTROLS 1F – 271
DAEWOO V–121 BL4
DTC P0562 – System Voltage(Engine Side) Too Low
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. 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
31. 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 val-
ue?1,400rpm 12VGo to Step 4Go to
”Diagnostic
Aids”
41. 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 val-
ue?10VGo to Step 5Go to Step 6
5Check for a malfunctioning connection at the ECM
harness terminals and repair as necessary.
Is a repair necessary?–Go to Step 8Go to Step 7
6Repair 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–
81. 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 9Go to Step 2
9Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
applicable DTC
tableSystem OK

ENGINE CONTROLS 1F – 273
DAEWOO V–121 BL4
DTC P0563 – System Voltage(Engine Side) Too High
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. 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
31. 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 val-
ue?1,400rpm 12VGo to Step 4Go to
”Diagnostic
Aids”
41. 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 val-
ue?10VGo to Step 5Go to Step 6
5Check for a malfunctioning connection at the ECM
harness terminals and repair as necessary.
Is a repair necessary?–Go to Step 8Go to Step 7
6Repair 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–
81. 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 9Go to Step 2
9Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
applicable DTC
tableSystem OK

1F – 284IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P1230 – Fuel Pump Relay Low Voltage (1.4L 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
31. Turn the ignition switch to ON.
2. Disconnect the fuel pump relay.
3. Connect a test light between the fuel pump
relay connector terminal 85 and ground.
4. Turn the Turn the ignition switch to ON.
Is the test light ON?–Go to Step 4Go to Step 10
41. Turn the ignition switch to ON.
2. Disconnect the fuel pump relay.
3. Connect a test light between the fuel pump
relay connector terminal 86 and B+.
4. Turn the Turn the ignition switch to ON.
Is the test light ON?–Go to Step 5Go to Step 9
51. Turn the ignition switch to LOCK.
2. Connect a test light between the fuel pump
relay connector terminal 30 and ground.
Is the test light ON?–Go to Step 6Go to Step 8
6Check for short to ground in the wire between the
fuel pump relay connector terminal 87 and fuel pump
connector.
Is the problem found?–Go to Step 7Go to Step 8
71. 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–
81. 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 14Go to Step 9
9Check for a short to ground wire between the fuel
pump relay connector terminal 86 and the ignition af-
ter key ON(IGN 1).
Is the problem found?–Go to Step 11Go to Step 10
10Check for a short to ground wire between the fuel
pump relay connector terminal 85 and the ECM con-
nector terminal 6.
Is the problem found?–Go to Step 12Go to Step 13

ENGINE CONTROLS 1F – 287
DAEWOO V–121 BL4
DTC P1230 – Fuel Pump Relay Low 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
31. Turn the ignition switch to ON.
2. Disconnect the fuel pump relay.
3. Connect a test light between the fuel pump
relay connector terminal 85 and ground.
4. Turn the Turn the ignition switch to ON.
Is the test light ON?–Go to Step 4Go to Step 10
41. Turn the ignition switch to ON.
2. Disconnect the fuel pump relay.
3. Connect a test light between the fuel pump
relay connector terminal 86 and B+.
4. Turn the Turn the ignition switch to ON.
Is the test light ON?–Go to Step 5Go to Step 9
51. Turn the ignition switch to LOCK.
2. Connect a test light between the fuel pump
relay connector terminal 30 and ground.
Is the test light ON?–Go to Step 6Go to Step 8
6Check for short to ground in the wire between the
fuel pump relay connector terminal 87 and fuel pump
connector.
Is the problem found?–Go to Step 7Go to Step 8
71. 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–
81. 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 14Go to Step 9
9Check for a short to ground wire between the fuel
pump relay connector terminal 86 and the ignition af-
ter key ON(IGN 1).
Is the problem found?–Go to Step 11Go to Step 10
10Check for a short to ground wire between the fuel
pump relay connector terminal 85 and the ECM con-
nector terminal 6.
Is the problem found?–Go to Step 12Go to Step 13

ENGINE CONTROLS 1F – 311
DAEWOO V–121 BL4
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illuminate
after three consecutive trip with a fail.
S The ECM will record operating conditions at the
time the diagnostic fail. 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.
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
Due to moisture associated with exhaust systems, the
EGR valve may freeze and stick in cold weather at times.
After the vehicle is brought into a warm shop for repairs,
the valve warms and the problem disappears.
By watching the Actual EGR and desired EGR positions
on a cold vehicle with a scan tool, the fault can be easily
verified. Check the Freeze Frame data to determine if the
DTC set when the vehicle was cold by viewing the Engine
Coolant Temperature (ECT).
DTC P1403 – Exhaust Gas Recirculation Valve Failure
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 with the engine OFF.
2. Install the scan tool.
3. Command the exhaust gas recirculation (EGR)
valve to the specified values.
Does the Actual EGR Position follow the desired
EGR position?25%, 50%
75%, 100%Go to Step 19Go to Step 3
31. Turn the ignition switch to ON.
2. Disconnect the EGR valve electrical connector.
3. With a test light connected to B+, probe the
ground circuit to the EGR valve.
Does the test light illuminate?–Go to Step 4Go to Step 5
41. Connect the test light to ground.
2. Probe the EGR control circuit at terminal 3 to
the EGR valve.
3. Command the EGR valve to the specified val-
ues using a scan tool.
After the command is raised, does the test light glow
brighter, flash or maintain a steady glow?25%, 50%
75%, 100%Go to Step 6Go to Step 7
5Repair the open or poor connection in the EGR
ground circuit.
Is the repair complete?–Go to Step 19–
6With a test light still connected to ground, probe the
signal circuit at terminal 3.
Does the test light illuminate?–Go to Step 8Go to Step 9
7With a test light still connected to ground, again
probe the signal circuit without commanding the
EGR valve with the scan tool.
Does the test light illuminate?–Go to Step 10Go to Step 11
8Check the signal circuit for a short to voltage and re-
pair as necessary.
Is a repair necessary?–Go to Step 19Go to Step 12