TEST 5: Switching Signal For Cylinders 1 And 4
In this test step, you're going to verify that the ignition coil (within the coil pack) that fires spark to cylinders 1 and 4 is being supplied with a Switching signal.
This test is done with the coil pack connected to its connector.
Alright, let's start:
- 1
Connect the black lead of the LED light to the wire identified with the number 1 in the image viewer.
This is the wire that feeds the Switching signal to the ignition coil (within the coil pack) that feeds spark to cylinders 1 and 4 simultaneously. - 2
Connect the red lead of the LED light to the battery positive (+) terminal.
- 3
Have your helper crank the car (the engine may start so be careful).
- 4
If the engine starts, have your helper turn it OFF.
- 5
If the Switching signal is present, the LED light will flash ON and OFF the whole time the engine was cranking and during the time it was running.
Let's find out what your test result means:
CASE 1: The LED light flashed ON and OFF the whole time the engine was cranking or running. With this test result you can conclude that the PCM is providing the Switching signal and the circuit is OK.
You can conclude that the ignition coil pack is bad if you have:
- Confirmed that the spark plug wires for cylinders 1 and 4 are not sparking (TEST 1).
- Confirmed that the ignition coil towers for cylinders 1 and 4 are not sparking (TEST 3).
- Confirmed that the ignition coil pack is receiving the 1/4 activation signal from the fuel injection computer in this test section.
CASE 2: The LED Light DID NOT flash ON and OFF the whole time the engine was cranking or running. This test result usually means that there's either an open-circuit in the circuit between the connector and the PCM or the PCM is fried (altho' a fried PCM is rare).
With this result you have eliminated the coil pack as the source of the misfire condition or no-spark condition.
TEST 6: Switching Signal For Cylinders 2 And 3
Here you're going to verify that the ignition coil (within the coil pack) that fires spark to cylinders 2 and 3 is receiving its switching signal from the PCM. This signal test is done with the coil pack's connector connected to it.
These are the test steps:
- 1
Connect the black lead of the LED light to the wire identified with the number 3 in the image viewer.
This is the wire that feeds the Switching signal to the ignition coil (within the coil pack) that feeds spark to cylinders 2 and 3 simultaneously. - 2
Connect the red lead of the LED light to the battery positive (+) terminal.
- 3
Have your helper crank the car (the engine may start so be careful).
- 4
If the engine starts, have your helper turn it OFF.
- 5
If the Switching signal is present, the LED light will flash ON and OFF the whole time the engine was cranking and during the time it was running.
Let's find out what your test result means:
CASE 1: The LED light flashed ON and OFF the whole time the engine was cranking or running. This is the correct test result and it means that the PCM is providing the Switching signal and the circuit is OK.
You can conclude that the ignition coil pack is bad if you have:
- Confirmed that the spark plug wires for cylinders 2 and 3 are not sparking (TEST 1).
- Confirmed that the ignition coil towers for cylinders 2 and 3 are not sparking (TEST 3).
- Confirmed that the ignition coil pack is receiving the 2/3 activation signal from the fuel injection computer in this test section.
CASE 2: The LED light DID NOT flash ON and OFF the whole time the engine was cranking or running. This usually means that there's either an open-circuit problem in the wire between the connector and the PCM or the PCM is fried (altho' a fried PCM is rare).
With this result you have eliminated the coil pack as the source of the misfire condition or no-spark condition.
