Honda Civic. Manual — part 785

Is there continuity?

YES -Go to step 5.

NO -Repair open in the wire between ignition coil relay 4P socket terminal No.
1 and ignition coil 3P connector terminal No. 3.

5. Check for continuity between each ignition coil 3P connector terminal NO. 2

and the body ground.

Fig. 8: Checking For Continuity Between Each Ignition Coil 3P Connector
Terminal No. 2 And The Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

2008 Honda Civic EX

2006-08 ENGINE Ignition System (R18A1) - Civic (All Except Hybrid)

Is there continuity?

YES -Go to step 6.

NO -Repair open in the wire between ignition coil relay 3P socket terminal No.
2 and body ground.

6. Connect the Honda Diagnostic System (HDS) to the data link connector (DLC)

(see step 2 on HOW TO USE THE HDS (HONDA DIAGNOSTIC
SYSTEM) ).

7. Turn the ignition switch ON (II).
8. Make sure the HDS communicates with the vehicle and the engine control

module (ECM)/powertrain control module (PCM). If it doesn't, troubleshoot
the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ).

9. Jump the SCS line with the HDS, then turn the ignition switch OFF.

10. Disconnect ECM/PCM connector A (44P).
11. Check for continuity between ignition coil relay 4P socket terminal No. 3 and

body ground.

Fig. 9: Checking For Continuity Between Ignition Coil Relay 4P Socket
Terminal No. 3 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

NOTE:

This step must be done to protect the ECM/PCM from
damage.

2008 Honda Civic EX

2006-08 ENGINE Ignition System (R18A1) - Civic (All Except Hybrid)

YES -Repair short in the wire between ignition coil relay 4P socket terminal
No. 3 and the ECM/PCM (A20).

NO -Go to step 11.

12. Check for continuity between ignition coil relay 4P socket terminal No. 3 and

ECM/PCM connector terminal A20.

Fig. 10: Checking For Continuity Between Ignition Coil Relay 4P Socket
Terminal No. 3
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -The system is OK at this time. Check for loose or poor connections at
the ignition coil relay and the ECM/PCM (A20).

NO -Repair open in the wire between ignition coil relay 4P socket terminal No.
3 and the ECM/PCM (A20).

SPARK PLUG INSPECTION

1. Remove the spark plugs and inspect the electrodes and the ceramic insulator.

Burned or worn electrodes may be caused by:

Advanced ignition timing

2008 Honda Civic EX

2006-08 ENGINE Ignition System (R18A1) - Civic (All Except Hybrid)

Loose spark plug

Plug heat range too hot

Insufficient cooling

Fouled plugs may be caused by:

Retarded ignition timing

Oil in combustion chamber

Incorrect spark plug gap

Plug heat range too cold

Excessive idling/low speed running

Clogged air cleaner element

Deteriorated ignition coils

Fig. 11: Identifying Worn Or Deformed Electrodes, Damaged
Gasket, Cracked Insulator And Improper Gap
Courtesy of AMERICAN HONDA MOTOR CO., INC.

2. If the spark plug electrode is dirty or contaminated, clean the electrode with a

plug cleaner.

NOTE:

Do not use a wire brush or scrape the iridium

2008 Honda Civic EX

2006-08 ENGINE Ignition System (R18A1) - Civic (All Except Hybrid)