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Home >> Mazda >> 2017 >> 5 GT, Automatic Trans >> Repair and Diagnosis >> Engine Performance >> System >> Symptom Troubleshooting - Engine Control >> Engine Control System Operation Inspection >> Spark Test
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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.
SPARK TEST INSPECTION PROCEDURE

STEP INSPECTION ACTION
1 Disconnect the ignition coil from the spark plugs.
Remove the spark plugs.
(See SPARK PLUG REMOVAL/INSTALLATION .)
Verify that the spark plugs do not have carbon deposits.
Is there any malfunction?
Yes Perform no-load racing at 4, 000 RPM for 2 min, 2 times to burn off the carbon deposits.
Repeat Step 1.
No Go to the next step.
2 Inspect the spark plugs for damage, wear, and proper plug gap.
Is there any malfunction?
Yes Replace the spark plugs, then go to Step 1.
(See SPARK PLUG REMOVAL/INSTALLATION .)
No 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 the engine?
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 Switch the ignition to off.
Inspect for open or short circuit between the following terminals (wiring harness-side):
  • Ignition coil No. 1 terminal C-PCM terminal 2G
  • Ignition coil No. 2 terminal C-PCM terminal 2K
  • Ignition coil No. 3 terminal C-PCM terminal 2L
  • Ignition coil No. 4 terminal C-PCM terminal 2H

Is there any malfunction?
Yes Repair or replace the suspected wiring harness, then go to Step 1.
No Inspect and replace the ignition coil, then go to Step 1.
(See IGNITION COIL INSPECTION .)
(See IGNITION COIL REMOVAL/INSTALLATION .)
5 Switch the ignition to off.
Disconnect the ignition coil connector.
Switch the ignition to ON (engine off).
Measure the voltage at the terminal A (wiring harness-side) in each ignition coils.
Is the voltage B+?
Yes Go to the next step.
No Inspect for power supply circuit in wiring harness between ignition switch and ignition coils.
Repair or replace the suspected wiring harness, then go to Step 1.
6 Switch the ignition to off.
Inspect for continuity between terminal B (wiring harness-side) in each ignition coils and body ground.
Is there continuity?
Yes Go to the next step.
No Inspect the connection of PCM ground point.
  • If there is any malfunction:
    • Repair or replace the malfunctioning part according to the inspection results.
  • If there is no malfunction:
    • Repair or replace the wiring harness for a possible open circuit.

Repeat from Step 1.
7 Inspect the PCM and ignition coil connector or terminals for poor connection.
Is there any malfunction?
Yes Repair or replace the malfunctioning connector and/or terminals, then go to Step 1.
No Go to the next step.
8 Inspect the CKP sensor and crankshaft pulley.
(See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION .)
Is there any malfunction?
Yes Repair or replace the malfunctioning part according to the inspection results, then go to Step 1.
No Inspect for open or short circuit in wiring harness and connector of CKP sensor.
Repair or replace the malfunctioning part according to the inspection results, then go to Step 1.