Ignition System Check - Daewoo CIELO EURO III Manual

Circuit Description
The Electronic Ignition (EI) system uses a waste spark
method of spark distribution. In this type of EI system,
the Crankshaft Position (CKP) sensor is mounted to the
oil pump near a slotted wheel that is a part of the crank-
shaft pulley. The CKP sensor sends reference pulses to
the engine contro module (ECM).
The ECM then triggers the EI system ignition coil.
Once the ECM triggers the EI
system ignition coil, both of the connected spark plugs
fire at the same time. One cylinder is on its compression
stroke at the same time that the other is on the exhaust
stroke, resulting in lower energy needed to fire the spark
plug in the cylinder on its exhaust stroke.
This leaves the remainder of the high voltage to be used
to fire the spark plug in the cylinder on its compression
stroke. Since the CKP sensor is in a fixed position, tim-
ing adjustments are not possible or needed.
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
Caution: Use only electrically insulated pliers when handling ignition wires with the engine running to pre-
vent an electrical shock.
Step
1. Remove the spark plugs.
2. Inspect for wet spark plugs, cracks, wear, improper
gap, burned electrodes, or heavy deposits.
1
3. Replace the spark plugs as needed.
Is the repair complete?
Check for the presence of spark from all of the igni-
tion wires while cranking the engine.
2
Is spark present from all of the ignition wires?
1. Measure the resistance of the ignition wires.
2. Replace any ignition wire(s) with a resistance
above the value specified.
3
3. Check for the presence of spark from all of the
ignition wires.
Is spark present from all of the ignition wires?
Is spark present from at least one of the ignition
4
wires, but not all of the ignition wires?
DAEWOO T-154 BL2,3

IGNITION SYSTEM CHECK

Ignition System Check
Action
ENGINE CONTROLS 1F – 6 7
2. It is important to check for the presence of spark to
all of the cylinders to isolate the problem to either EI
system ignition coil inputs or outputs.
5. In checking the ECM outputs for the electronic
spark timing signal, it recommended to use an oscil-
loscope to view the varying voltage signals. In mea-
suring these outputs with a voltmeter, intermittent
errors may occur that cannot be seen by a voltmeter.
6. After confirming ECM inputs for the electronic
spark timing to the EI system ignition coil are OK, it
can be determined that a faulty EI system ignition
coil is at fault.
11. After confirming proper CKP sensor inputs to the
ECM and no wiring problems present, it can
be determined that the ECM is at fault.
24. This step, along with step 25, checks for battery
voltage and a ground to the EI system ignition coil.
Value(s)
–
System OK
–
System OK
30,000 System OK
– Go to Step 5
Yes No
Go to Step 2
Go to Step 3
Go to Step 4
Go to Step 12