Daewoo MATIZ Service Manual page 361

DIAGNOSTIC TROUBLE CODE (DTC) – P0604 ENGINE CONTROL MODULE
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.
Step
Perform an On-Board Diagnostic (EOBD) System
Check.
1
Is the system check complete?
Replace the engine control module(ECM).
2
Is the replacement complete?
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
3
setting this DTC ad specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?
Check if any additional DTCs are set.
4
Are any DTCs displayed that have not been
diagnosed?
DAEWOO M-150 BL2
INTERNAL/EXTERNAL RAM ERROR
DTC P0604 – Engine Control Module RAM Error
Action
ENGINE CONTROLS 1F – 263
Conditions for Setting the DTC
D The ECM detects more than 3 incorrect checksum.
Action taken when The DTCs 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 Failure 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 four consecutive ignition
cycles in which the diagnostic runs without a fault.
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.
Value(s)
–
Go to Step 2
–
Go to Step 3
–
Go to Step 4
applicable DTC
–
Yes No
Go to
"On-Board
Diagnostic
System Check"
–
Go to Step 2
Go to
table System OK