Compression Check: Testing and Inspection
Engine Compression InspectionNOTE: After this inspection, you must reset the powertrain control module (PCM), otherwise the PCM will continue to stop the injectors from functioning. Select PCM reset using the Honda Diagnostic System (HDS).
1. Warm up the engine to normal operating temperature (cooling fan comes on).
2. Turn the ignition switch OFF.
3. Connect the HDS to the data link connector (DLC).
4. Turn the ignition switch ON (II), select PGM-FI, INSPECTION, and then ALL INJECTORS OFF on the HDS.
NOTE: If the HDS does not communicate with the PCM, go to the DLC circuit troubleshooting.
5. Remove the four intake side ignition coils.
6. Remove the four intake side spark plugs.
7. Attach the compression gauge to a spark plug hole.
NOTE: Use a compression gauge with a connecting length (between the edge and the flange) of less than 23 mm (0.9 inch).
8. Remove the No. 61 +B IMA 2 (10 A) fuse in the auxiliary under-hood fuse/relay box.
9. Open the throttle fully, then crank the engine with the starter motor and measure the compression.
Compression Pressure: Above 980 kPa (10.0 kgf/cm2, 142 psi)
10. Measure the compression on the remaining cylinders.
Maximum Variation: Within 200 kPa (2.0 kgf/cm2, 29 psi)
11. If the compression is not within specifications, check the following items, then remeasure the compression.
^ Looseness exhaust side spark plug
^ Damaged or worn valves and seats
^ Damaged cylinder head gasket
^ Damaged or worn piston-rings
^ Damaged or worn piston and cylinder bore
12. Remove the compression gauge from the spark plug hole.
13. Install the four intake side spark plugs.
14. Install the four intake side ignition coils.
15. Select PCM reset to cancel the ALL INJECTORS OFF function on the HDS.
16. Install the No. 61 +B IMA 2 (10 A) fuse in the auxiliary under-hood fuse/relay box.
17. Clear any IMA DTCs that may have been set while doing this inspection procedure.
18. If the IMA battery level gauge (BAT) displays no segment, start the engine, and hold it between 3,500 rpm and 4,000 rpm without load (in Park or neutral) until the BAT displays at least three segments.