Compression Check: Testing and Inspection

Engine Compression Inspection

NOTE: After the inspection, you must reset the engine control module (ECM)/the powertrain control module (PCM). Otherwise, the ECM/PCM will continue to stop the fuel injectors from functioning.

1. Warm up the engine to normal operating temperature (the radiator fan comes on at least twice).
2. Turn the ignition switch OFF.
3. Connect the Honda Diagnostic System (HDS) to the data link connector (DLC).
4. Turn the ignition switch ON (II).
5. '07-08 models: Make sure the HDS communicates with the vehicle and the ECM/PCM. If it doesn't communicate, troubleshoot the DLC circuit.
6. Select PGM-FI, INSPECTION, then ALL INJECTORS OFF on the HDS.
7. Turn the ignition switch OFF.
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/cm2, 135 psi)

12. Measure the compression of the remaining cylinders.

Maximum Variation:
Within 200 kPa (2.0 kgf/cm2, 29 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. Remove the compression gauge from the spark plug hole.
15. Install the four spark plugs.
16. Install the four ignition coils.
17. Select ECM/PCM reset to cancel the ALL INJECTORS OFF on the HDS.
18. Do the ECM/PCM idle learn procedure.