Spark Test

WARNING: This page is about a different car, the 2009 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

Disconnect the fuel pump relay.
Verify that each ignition coil and connector is connected properly.
Inspect the ignition system in the following procedure.

WARNING:

High voltage in the ignition system can cause strong electrical shock which can result in serious injury. Avoid direct contact to the vehicle body during the following spark test.

DIAGNOSTIC PROCEDURE CHART

STEP	INSPECTION		ACTION
1	Disconnect the ignition coil from the spark plugs. Remove the spark plugs. Ensure that the spark plugs don't have carbon deposits. Are the spark plugs OK?	Yes	Go to the next step.
1		No	Perform 2 times of no-load racing at 4000 RPM for 2 min to burn off the carbon deposits. Then repeat this step.
2	Inspect the spark plugs for damage, wear, and proper plug gap Are the spark plugs normal?	Yes	Go to the next step.
2		No	Replace spark plugs, then go to the next step.
3	Reconnect the spark plugs to the ignition coil Ground the spark plugs to the engine. Is a strong blue spark visible at each cylinder while cranking?	Yes	Ignition system is normal.
3		No	Some cylinders do not spark: Go to the next step. All cylinders do not spark: Go to Step 5.
4	Inspect the following wiring harnesses for open or short: Ignition coil No. 1 terminal C-PCM terminal 2BB Ignition coil No 2 terminal C-PCM terminal 2AT Ignition coil No. 3 terminal C-PCM terminal 2B Ignition coil No 4 terminal C-PCM terminal 2AX Ignition coil No. 5 terminal C-PCM terminal 2C Ignition coil No. 6 terminal C-PCM terminal 2D Are the wiring harnesses normal?	Yes	Inspect and replace the ignition coil. (See IGNITION COIL INSPECTION [MZI-3.7] .)
4		No	Repair or replace the malfunctioning part, then go to Step 1.
5	Measure the voltage at terminal A in each ignition coils. Is the voltage B+ ?	Yes	Go to the next step.
5		No	Inspect power supply circuit of ignition coils.
6	Verify continuity between each ignition coils terminal B and battery negative post. Is there any continuity?	Yes	Go to the next step.
6		No	Inspect GND circuit of ignition coils.
7	Does the PCM connector or ignition coil connectors have poor connection?	Yes	Repair or replace the connector, then go to Step 1.
7		No	Go to the next step.
8	Are the following parts normal? CKP sensor and crankshaft pulley	Yes	Inspect for open or short circuit in wiring harness and connector of CKP sensor.
8		No	Repair or replace the malfunctioning part, then go to Step 1.