Compression Check: Testing and Inspection

Engine Compression Inspection

NOTE:
^ '00 - 05 models: After the inspection, you must reset the engine control module (ECM) using the Honda Diagnostic System (HDS), to clear any diagnostic trouble codes (DTCs).
^ '06 - 08 models: After the inspection, you must reset the ECM using the HDS. Otherwise, the ECM continues to stop the fuel injectors.

1. Warm up the engine to normal operating temperature (cooling fan comes on).
2. '00 - 05 models: Remove the No. 2 (15 A) fuse from the under-dash fuse/relay box.
3. '06 - 08 models: Connect the HDS to the data link connector (DLC).
4. Turn the ignition switch to ON (11).
5. '06 - 08 models: Make sure the HDS communicates with the vehicle and the ECM. If it doesn't communicate, troubleshoot the DLC circuit.
6. '06 - 08 models: Select PGM-FI, INSPECTION, then ALL INJECTORS OFF on the HDS.
7. Turn the ignition switch to LOCK (0).
8. Remove the four ignition coils.
9. Remove the four spark plugs.
10. Attach the compression gauge to the spark plug hole.





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

Compression Pressure:
Above 930 kPa (9.5 kgf/cm, 135 psi)

12. Measure the compression on the remaining cylinders.

Maximum Variation:
Within 200 kPa (2.0 kgf/cm, 28 psi)

13. 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

14. '00 - 05 models: Reinstall the No. 2 (15 A) fuse in the under-dash fuse/relay box.
15. '00 - 05 models: Select ECM reset on the HDS.
16. '06 - 08 models: Select ECM reset to cancel the ALL INJECTOR OFF on the HDS.
17. Do the ECM idle learn procedure.