Daewoo CIELO EURO III Manual page 443

IGNITION CONTROL CIRCUIT A FAULT (CYLINDER 1 AND 4)
Circuit Description
The engine control
module (ECM) provides a ground for the electronic
spark timing A circuit. When the ECM removes the
ground path of the ignition primary coil, the magnetic
field produced by the coil collapses. The collapsing mag-
netic field produces a voltage in the secondary coil
which fires the spark plug. The circuit between the
ECM and the electronic ignition system is monitored for
an open circuit, short to voltage, and short to ground.
When the ECM detects a problem in the spark tim-
ing B circuit, it will set DTC P0351.
Conditions for Setting the DTC
Ignition ON.
1.5L SOHC
Fault flag increments fail count.
Must receive more than 20 failure within 40 test
cycles.
Action Taken When the DTC Sets
The ECM will illuminate the Malfunction Indica-
tor Lamp (MIL) the first time the fault is detected.
The ECM will store conditions which were pres-
ent when the Diagnostic Trouble Code (DTC) was set
as Freeze Frame and in the Failure Records data.
A history DTC is stored.
Conditions for Clearing the MIL/DTC
The ECM will turn the MIL OFF on the third
(fourth – 1.5L SOHC) consecutive trip
cycle during which the diagnostic has been run and
the fault condition is no longer present.
DAEWOO T-154 BL2,3
DIAGNOSTIC TROUBLE CODE (DTC) P0351
ENGINE CONTROLS 1F – 273
A history DTC will clear after 40 consecutive warm up
cycles have occurred without a fault.
DTC(s) can be cleared by using the scan tool.
Diagnostic Aids
An intermittent may be caused by a poor connection,
rubbed-through wire insulation or a wire broken inside
the insulation. Check for:
Poor connection – Inspect the ECM harness
and connectors for improper mating, broken locks,
improperly formed or damaged terminals, and poor
terminal-to-wire connection.
Damaged harness – Inspect the wiring harness for
damage. If the harness appears to be OK, disconnect
the ECM, turn the ignition on, and observe a
voltmeter connected to the 58X reference circuit at
the ECM harness connector while moving con-
nectors and wiring harnesses related to the
ECM. A change in voltage will indicate the location of
the fault.
Reviewing the Failure Records vehicle mileage since
the diagnostic test last failed may help determine how
often the condition that caused the DTC to be set oc-
curs. This may assist in diagnosing the condition.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Table.
1. The On-Board Diagnostic (EOBD) system check
prompts the technician to complete some backs and
store the freeze frame and failure records data on
the scan tool if applicable. This creates an electronic
copy of the data taken when the malfunction oc-
curred. The information is then stored on the scan
tool for later reference.
7. The replacement ECM must be repro-
grammed. Refer to the latest Techline procedure for
ECM reprogramming.