DTC Troubleshooting

DTC Troubleshooting: P2646

DTC P2646: VTEC System Stuck OFF

Special Tools Required

- Pressure gauge adapter 07NAJ-P07010A
- A/T low pressure gauge w/panel 07406-0070301
- A/T pressure hose, 2,210 mm 07AAJ-PY4A100
- A/T pressure adapter 07MAJ-PY40120
- Oil pressure hose 07ZAJ-S5AA200
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information. Reading and Clearing Diagnostic Trouble Codes

1. Check the engine oil level.

Is the engine oil level OK?
YES - Go to step 2.

NO - Adjust the engine oil to the proper level, then go to step 12.


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

3. Clear the DTC with the HDS.

4. Do the VTEC TEST in the INSPECTION MENU with the HDS.

Is the result OK?
YES - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the rocker arm oil pressure sensor (EOP sensor), the rocker arm oil control solenoid, and the ECM/PCM.

NO - Go to step 5.


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

6. Remove the rocker arm oil pressure sensor (EOP sensor) (A), attach the special tools as shown, then attach the rocker arm oil pressure sensor (EOP sensor) to the oil pressure gauge adapter (B).
NOTE: Install the parts in the reverse order of removal with a new O-ring.

7. Start the engine. Hold the engine speed at 3,000 rpm without load (A/T in P or N, M/T in neutral) until the radiator fan comes on, then let it idle for 2 minutes.

8. Do the VTEC TEST in the INSPECTION MENU with the HDS.

9. Check the oil pressure.

Does the oil pressure increase to at least 30 kPa (4.3 psi, 0.3 kgf/cm2)?
YES - Replace the rocker arm oil pressure sensor (EOP sensor), Service and Repair then go to step 10.

NO - Inspect the following items. If they are OK, replace the rocker arm oil control valve, Service and Repair then go to step 10.

- VTEC system oil line

- Operation of the rocker arm VTEC Rocker Arm Test







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

11. Reconnect all connectors.

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

13. Reset the ECM/PCM with the HDS.

14. Do the ECM/PCM idle learn procedure. ECM/PCM Idle Learn Procedure

15. Test-drive under these conditions:
- Engine coolant temperature (ECT SENSOR 1) above 167 °F (75 °C)

- A/T in D, M/T in 3rd

- Engine speed at 1,100-3,300 rpm

16. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P2646 indicated?
YES - Check for poor connections or loose terminals at the rocker arm oil control solenoid, the rocker arm oil pressure sensor (EOP sensor), and the ECM/PCM, then go to step 1.

NO - Go to step 17.


17. Monitor the OBD STATUS for DTC P2646 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?
YES - Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 16, go to the indicated DTC's troubleshooting.

NO - If the screen indicates FAILED, check for poor connections or loose terminals at the rocker arm oil control solenoid, the rocker arm oil pressure sensor (EOP sensor), and the ECM/PCM, then go to step 1. If the screen indicates NOT COMPLETED, go to step 15.