1. Insert BLACK test lead into COM test lead jack.
2. Insert RED test lead into test lead jack.
3. Turn the meters range selector to the 20KΩ range.
Refer to vehicles service manual for recommended
resistance outputs.
If the test results are within specifications, you
should check the sensor’s electrical connector and
the wiring harness. The trigger wheel located on the
crankshaft or damper could have damaged or
missing teeth. Any of these components could
trigger a CKP sensor to trouble code. Completing
the above tests thoroughly will let you know if the
crankshaft position sensor is working or not.
Pick-up Coil Resistance
The resistance test checks for open circuits or high
resistance. The voltage test compares voltage
output to resistance.
1. Insert the BLACK test lead into COM test lead jack.
2. Insert RED test lead into test lead jack.
3. Turn meters range selector to 200Ω range.
4. Connect the RED and BLACK test leads to the
pick-up coil leads from the distributor. View the
displayed results.
The majority of the pick-up coils will test between
500 - 1500Ω’s resistances. Refer to vehicle service
manual for your vehicles resistance range.
5. Set range selector to AC volts. Crank the engine 10
– 15 seconds, view the voltage results on the display.
Resistance on a good pick-up coil will match the AC
output voltage. For example 950Ω would equal
950mV output. Resistance can be good but voltage
low if the magnet has lost magnetism or if the
reluctor is too far from the stator.
Ignition Coil
The ignition coil is designed to transform the
battery’s low voltage to 30,000 volts to bridge the
spark plugs and ignite the fuel. Coils consist of a
laminated iron core surrounded by two coils of
copper wire. The Primary winding has just a few
turns of heavy wire. The Secondary winding has
thousands of turns of smaller wire. Today’s vehicle
uses one ignition coil for each cylinder called COP,
or coil on plug. This improvement system eliminates
the fault-prone spark plug cables and a distributor to
route the high voltage pulses. This test measures
the resistance across the primary and secondary
coils of the ignition coil. This test can be used for
distributor less ignition systems (DIS) providing the
primary and secondary ignition coil terminals are
easily accessible.
For testing the PRIMARY SIDE of the ignition coil
the engine must be cool and off. You’ll need to
IGNITION SYSTEM TESTS CONT.
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identify both the primary ignition coil terminals, (+)
positive and the (-) negative terminals. Once
identified disconnect them from the coil. It’s
recommended to mark the wires if they’re not color
coded, red (+) and black (-). Next remove the
center high tension lead that goes to the distributor.
1. Insert BLACK test lead into COM test lead jack.
2. Insert RED test lead into test lead jack.
3. Turn the meters range selector to the 200Ω
range. Because of the sensitivity of this test touch
the two probes of the test leads together. View the
reading on the display and record the resistance
value.
4. Add the alligator clips and connect the RED
clip to primary ignition coil positive (+) terminal.
5. Connect the BLACK clip to primary ignition coil
negative (-) terminal.
View the reading on the display, subtract the test
lead resistance value from above. Record this final
figure. If your vehicle has DIS, repeat the above
steps for each ignition coil and record the results.
Refer to your service manual for your vehicles
primary ignition coils resistance values.
• A common range for the primary side of the coil
is <2.0Ω.
For testing the SECONDARY SIDE of the ignition
coil, meter connections remain the same.
1. Turn the meters range selector to the 200KΩ
range.
2. Remove the alligator clip from the RED test
lead, and move the probe to the secondary ignition
coil terminal. Typically that’s the tower where the
high tension lead was plugged into.
3. Connect the BLACK clip to primary ignition coil
negative (-) terminal.
View and record the reading. If the vehicle has DIS,
repeat above steps for each coil, record the results.
• A common range for the secondary side of the coil
is 6 to 35KΩ.
Refer to your service manual for your vehicles
secondary ignition coils resistance values.
Because heat can affect resistance levels, repeat
the above tests with the engine at normal operating
temperature. Testing the coil hot helps to diagnosing
intermittent ignition system problems. Just be
cautious, the engine parts will be hot, gloves are
recommended.
• A good Ignition Coil Resistance readings were
within manufacturer’s specification.
Primary side of the coil is <2.0Ω.
Secondary side of the coil range is 6 to 35KΩ.
• A bad Ignition Coil Resistance readings were not
within manufacturer’s specification.
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