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Home >> Mazda >> 2012 >> CX-9 Touring, 3.7L Eng VIN V, FWD >> Repair and Diagnosis >> Engine Performance >> System >> Symptom Troubleshooting [Engine Control System MZI-3.7] >> Engine Control System Operation Inspection >> Spark Test

Spark Test

  1. Disconnect the fuel pump relay.
  2. Verify that each ignition coil and connector is connected properly.
  3. 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. 
IGNITION SYSTEM INSPECT PROCEDURE CHART

STEP INSPECTION RESULTS ACTION
1 Disconnect the ignition coil from the spark plugs.
Remove the spark plugs.
(See SPARK PLUG REMOVAL/INSTALLATION article.
  • Ensure that the spark plugs don't have carbon deposits.

Are the spark plugs OK?		 Yes Go to the next step.
No Perform 2 times of no-load racing at 4000 rpm for 2 min  to burn off the carbon deposits.
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.
No Replace spark plugs, then go to the next step.
(See SPARK PLUG REMOVAL/INSTALLATION article.
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.
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 article.)
Repair or replace the malfunctioning part according to the inspection results.
No Repair or replace suspected wiring harness and connector, then go to Step 1.
5 Turn the ignition switch to the ON position
Measure the voltage at terminal A in each ignition coils.
Is the voltage B+  ?		 Yes Go to the next step.
No Inspect power supply circuit of ignition coils.
Repair or replace suspected wiring harness and connector.
6 Verify continuity between each ignition coils terminal B and battery negative terminal.
Is there any continuity?		 Yes Go to the next step.
No Inspect GND circuit of ignition coils.
Repair or replace suspected wiring harness and connector.
7 Does the PCM connector or ignition coil connectors have poor connection? Yes Repair or replace the connector, then go to Step 1.
No Go to the next step.
8 Is the CKP sensor and crankshaft pulley normal? Yes Inspect for open or short circuit in wiring harness and connector of CKP sensor.
Repair or replace suspected wiring harness and connector.
No Repair or replace the malfunctioning part, then go to Step 1.
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