IGNITION SYSTEM (FOR J20/H25 ENGINES) 6F2-5
Diagnosis
Diagnostic Flow Table
Condition Possible Cause Correction
Engine cranks, but will
not start or hard to
start
No spark
• Blown fuse for ignition coil assembly Replace
• Loose connection or disconnection of lead
wire
Connect securely
• Faulty spark plug(s) Adjust, clean or replace
• Faulty ignition coil assembly(s) Replace
• Faulty CMP sensor Replace
• Faulty ECM (or PCM) Replace
• Maladjusted ignition timing Adjust
Poor fuel economy or
engine performance
Incorrect ignition timing Adjust
Faulty spark plug(s) Adjust, clean or replace
Faulty ignition coil assembly(s) Replace
Faulty CMP sensor Replace
Faulty ECM (or PCM) Replace
Step Action Yes No
1Was “Engine Diagnostic Flow Table” in Section
6 or 6-1 performed?
Go to Step 2. Go to “Engine Diagnostic
Flow Table” in Section 6
or 6-1.
2 Ignition Spark Test
1) Check all spark plug for condition and type,
referring to “Spark Plug” in this section.
2) If OK, perform ignition spark test, referring
to “Ignition Spark Check” in this section.
Is spark emitted from all spark plugs?
Go to Step 8 on the next
page.
Go to Step 3.
3 Diagnostic Trouble Code (DTC) Check
1) Check DTC stored in ECM (or PCM), refer-
ring to “Diagnostic Trouble Code (DTC)
Check” in Section 6E1 or 6E2.
Is DTC stored?
Go to applicable flow table
corresponding to that
code No. in Section 6E1
or 6E2.
Go to Step 4.
4 Electrical Connection Check
1) Check ignition coil assemblies for electrical
connection.
Are they connected securely?
Go to Step 5. Connect securely.
5 Ignition Coil Assembly Power Supply, Ground
and Trigger Signal Circuits Check
1) Check these circuits for open and short.
Are circuits in good condition?
Go to Step 6. Repair or replace.
6 Ignition Coil Assembly Check
1) Substitute a known-good ignition coil
assembly and then repeat Step 2.
Is check result of Step 2 satisfactory?
Malfunction of ignition coil
assembly.
Go to Step 7.
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