Daewoo MATIZ Service Manual page 216

1F – 118 ENGINE CONTROLS
DIAGNOSTIC TROUBLE CODE (DTC) – P1231 FUEL PUMP RELAY HIGH
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
cranking or running and the ECM is receiving ignition
reference pulses.
Conditions for Setting the DTC
D This DTC can be stored in "key-on" status.
D A high voltage condition exists.
Action Taken when the DTC Sets
D The Malfunction Indicator Lamp (MIL) will illuminate.
D The ECM will record operating conditions at the time
the diagnostic fails. This information will be stored in
the Freeze Frame and Records buffers.
D A history DTC is stored.
D Coolant fan turns ON.
Conditions for Clearing the MIL/DTC
D The MIL will turn off after 4 consecutive ignition
cycles in which the diagnostic runs without a fault.
VOLTAGE
D A history DTC will clear after 40 consecutive warm up
cycles without a fault.
D DTC(s) can be cleared by using the scan tool.
D Disconnecting the ECM battery feed for 10 seconds.
Diagnostic Aids
An Intermittent problem may be caused by a poor con-
nection, rubbed through wire insulation, or wire that is
broken inside the insulation.
Any circuitry, that is suspected as causing the com-
plaint, should be thoroughly checked for the following
conditions.
D Backed-out terminals
D Improper mating
D Broken locks
D Improperly formed
D Damaged terminals
D Poor terminals to wire connection
D Physical damage to the wiring harness
MAA1F040
DAEWOO M-150 BL2