Compression Check: Testing and Inspection

Engine Compression Inspection

NOTE: After this inspection, you must reset the engine control module (ECM)/powertrain control module (PCM), otherwise the ECM/PCM will continue to stop the injectors from functioning. Select ECM/PCM reset using the Honda Diagnostic System (HDS) Initial Inspection and Diagnostic Overview.

1. Warm up the engine to normal operating temperature (cooling fan comes on).

2. Turn the ignition switch to LOCK (0).

3. Connect the HDS to the data link connector (DLC) Initial Inspection and Diagnostic Overview.

4. Turn the ignition switch to ON (II).

5. Make sure the HDS communicates with the vehicle and the ECM/PCM. If it does not, troubleshoot the DLC circuit Testing and Inspection.

6. Select PGM-FI, INSPECTION, then ALL INJECTORS STOP function on the HDS.

7. Remove the four ignition coils Service and Repair.

8. Remove the four spark plugs.

9. Attach the compression gauge to the spark plug hole.





10. Open the throttle plate fully, then crank the engine with the starter motor and measure the compression.





11. Measure the compression on the remaining cylinders.





12. If the compression is not within specifications, check the following items, then remeasure the compression.

- Damaged or worn valves and seats
- Damaged cylinder head gasket
- Damaged or worn piston rings
- Damaged or worn piston and cylinder bore

13. Select ECM/PCM reset Initial Inspection and Diagnostic Overview to cancel the ALL INJECTORS STOP function on the HDS.