Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2006 Honda S2000 L4-2.2LFACTORY OEM SERVICE PROCEDURE
Ignition System: Testing and Inspection
Ignition Coil Relay Circuit Troubleshooting
2006 Model
1. Check the No. 16 (15 A) fuse in the under-dash fuse/relay box.
Is the fuse OK?
YES - Go to step 2.
NO - Replace the fuse.
2. Remove the ignition coil relay, and test it.
Is the relay OK?
YES - Go to step 3.
NO - Replace the ignition coil relay.
3. Measure the voltage between ignition coil relay 4P socket terminal No. 1 and body ground, then terminal No. 4 and body ground.
Is there battery voltage?
YES - Go to step 4.
NO - Repair an open in the wire between the under-dash fuse/relay box and the ignition coil relay 4P socket.
4. Check for continuity between ignition coil relay 4P socket terminal No. 2 and No. 1 ignition coil 3P connector terminal No. 3.
Is there continuity?
YES - Go to step 5.
NO - Repair an open in the wire between ignition coil relay 4P socket and the No. 1 ignition coil.
5. Connect the Honda Diagnostic System (HDS) to the data link connector (DLC).
6. Turn the ignition switch ON (II).
7. Make sure the HDS communicates with the vehicle and the engine control module (ECM). If it doesn't, troubleshoot the DTC circuit.
8. Jump the SCS line with the HDS.
NOTE: This step must be done to protect the ECM from damage.
9. Turn the ignition switch OFF.
10. Disconnect ECM connector E (31P).
11. Check for continuity between ignition coil relay 4P socket terminal No. 3 and body ground.
Is there continuity?
YES - Repair a short to ground in the wire between the ignition coil relay 4P socket and the ECM (E7).
NO - Go to step 12.
12. Check for continuity between ignition coil relay 4P socket terminal No. 3 and ECM connector terminal E7.
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 (E7).
NO - Repair an open in the wire between ignition coil relay 4P socket and the ECM (E7).
2006 Model
1. Check the No. 16 (15 A) fuse in the under-dash fuse/relay box.
Is the fuse OK?
YES - Go to step 2.
NO - Replace the fuse.
2. Remove the ignition coil relay, and test it.
Is the relay OK?
YES - Go to step 3.
NO - Replace the ignition coil relay.
3. Measure the voltage between ignition coil relay 4P socket terminal No. 1 and body ground, then terminal No. 4 and body ground.
Is there battery voltage?
YES - Go to step 4.
NO - Repair an open in the wire between the under-dash fuse/relay box and the ignition coil relay 4P socket.
4. Check for continuity between ignition coil relay 4P socket terminal No. 2 and No. 1 ignition coil 3P connector terminal No. 3.
Is there continuity?
YES - Go to step 5.
NO - Repair an open in the wire between ignition coil relay 4P socket and the No. 1 ignition coil.
5. Connect the Honda Diagnostic System (HDS) to the data link connector (DLC).
6. Turn the ignition switch ON (II).
7. Make sure the HDS communicates with the vehicle and the engine control module (ECM). If it doesn't, troubleshoot the DTC circuit.
8. Jump the SCS line with the HDS.
NOTE: This step must be done to protect the ECM from damage.
9. Turn the ignition switch OFF.
10. Disconnect ECM connector E (31P).
11. Check for continuity between ignition coil relay 4P socket terminal No. 3 and body ground.
Is there continuity?
YES - Repair a short to ground in the wire between the ignition coil relay 4P socket and the ECM (E7).
NO - Go to step 12.
12. Check for continuity between ignition coil relay 4P socket terminal No. 3 and ECM connector terminal E7.
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 (E7).
NO - Repair an open in the wire between ignition coil relay 4P socket and the ECM (E7).
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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