Engine Mount: Testing and Inspection

Troubleshooting

Special Tools Required
Vacuum pump/gauge, 0-30 in.Hg A973X-041-XXXXX

2003, 2004 Models

NOTE:
- Information marked with an asterisk (*) applies to 2004 Model.
- Check the vacuum hoses and lines for damage and proper connections before troubleshooting.

Follow this procedure if the engine vibrates excessively when idling.
1. Connect the Honda Diagnostic System (HDS) to the data link connector (DLC), and check for DTC's. If a DTC is present, diagnose and repair the cause.
2. Start the engine and let it idle.
3. Raise the engine speed from idling to 2,000 rpm.
4. Check the MOUNT CTRL SOL in the PGM-FI DATA LIST with the HDS.

Is ON indicated at idling and OFF indicated at 2,000 rpm?

YES - Go to step 5.

NO - Update the powertrain control module (PCM) if it does not have the latest software, or substitute a known-good PCM, then recheck. If the engine mount control system works properly, and the PCM was updated, the troubleshooting is complete. If the PCM was substituted, replace the original PCM.

5. Shift to Park or Neutral position.
6. Disconnect the engine mount control solenoid valve 2P connector from the engine mount control solenoid valve.




7. Measure voltage between engine mount control solenoid valve 2P connector terminal No.2 and body ground.

Is there battery voltage?

YES - Go to step 8.

NO - Repair an open in the wire between engine mount control solenoid valve and air fuel ratio sensor relay.




8. Measure voltage between engine mount control solenoid valve 2P connector terminals No.1 and No.2.

Is there battery voltage?

YES - Go to step 9.

NO - Repair an open in the wire between PCM and the engine mount control solenoid valve 2P connector. If the wire is OK, update the PCM if it does not have the latest software, or substitute a known-good PCM, and recheck. If the engine mount control system works properly, and the PCM was updated, the troubleshooting is complete. If the PCM was substituted, replace the original PCM.

9. Raise the engine speed above 1,000 rpm.




10. Measure voltage between engine mount control solenoid valve 2P connector terminals No.1 and No.2.

Is there battery voltage?

YES - Repair a short to body ground in the wire between PCM and the engine mount control solenoid valve. If the wire is OK, update the PCM if it does not have the latest software, or substitute a known-good PCM, and recheck. If the engine mount control system works properly, and the PCM was updated, the troubleshooting is complete. If the PCM was substituted, replace the original PCM.

NO - Go to step 11.




11. Disconnect the vacuum hose (A) that is closest to the solenoid connector from the engine mount control solenoid valve (B), and connect a vacuum pump/gauge to the hose. Apply vacuum for 20 seconds.

Does the engine mount hold vacuum?

YES - Go to step 12.

NO - Either the vacuum hose or the engine mount has a vacuum leak. Repair as needed.

12. Release the vacuum, then apply vacuum again.

Is there a noticeable change in idle smoothness with and without vacuum applied?

YES - Go to step 13.

NO - Replace the front engine mount.




13. Connect a vacuum pump/gauge to the engine mount control solenoid valve port (A) that is closest to the solenoid connector.

Is there manifold vacuum at idle, and a decrease in manifold vacuum when you raise the engine speed above 1,000 rpm?

YES - The system is OK.

NO - Replace the engine mount control solenoid valve.