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 07406-0020201
• A/T pressure hose, 2,210 mm 07MAJ-PY4011A
• A/T pressure hose, adapter 07MAJ-PY40120
• Oil pressure hose 07ZAJ-S5AA200

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, the rocker arm oil control solenoid, and the PCM.

   NO  - Go to step 5.

5. Turn the ignition switch to LOCK (0).
6. Remove the rocker arm oil pressure sensor (A), attach the special tools as shown, then attach the rocker arm oil pressure sensor to the oil pressure gauge adapter (B).
   Fig 1: Special Tools And Rocker Arm Oil Pressure Sensor With Torque Specification

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
7. Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) 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 (0.3 kgf/cm ²  , 4.3 psi)? 

   YES  - Replace the rocker arm oil pressure sensor (see ROCKER ARM OIL PRESSURE SENSOR REMOVAL/INSTALLATION ), then go to step 10.

   NO  - Replace the rocker arm oil control solenoid (see ROCKER ARM OIL CONTROL SOLENOID/ROCKER ARM OIL CONTROL SOLENOID FILTER REPLACEMENT ), then go to step 10.

10. Turn the ignition switch to LOCK (0).
11. Reconnect all connectors.
12. Turn the ignition switch to ON (II).
13. Reset the PCM with the HDS.
14. Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
15. Test-drive under these conditions:
    • Engine coolant temperature (ECT SENSOR 1) above 167°F (75°C)
    • Transmission in D
    • Engine speed at 1,500-3,000 rpm
16. Check for Temporary DTCs or 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, and the 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 Temporary DTCs or 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, rocker arm oil pressure sensor, and the PCM, then go to step  1. If the screen indicates NOT COMPLETED, go to step  15.