DTC P2646: VTEC System Stuck OFF

Special Tools Required 

• Pressure gauge adapter 07NAJ-P07010A
• A/T low pressure gauge w/panel 07406-0070300
• A/T pressure hose 07406-0020201
• A/T pressure hose, 2,210 mm 07MAJ-PY4011A
• A/T pressure adapter 07MAJ-PY40120
• Oil pressure hose 07ZAJ-S5A0200

1. Check the engine oil level.

   Is the engine oil level OK? 

   1. YES  - Go to step 2.
   2. NO  - Adjust the engine oil to the proper level, then go to step  12.
2. Turn the ignition switch 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? 

   1. YES  - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the EOP sensor, the rocker arm oil control solenoid (VTEC solenoid valve), and the PCM.
   2. NO  - Go to step 5.
5. Turn the ignition switch OFF.
6. Remove the EOP sensor (A), install the special tools as shown in Fig 1, then install the EOP sensor in the oil pressure gauge adapter (B).
   NOTE: Install the sensor in the reverse order of removal with new O-ring.
   Fig 1: Removing EOP Sensor

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
7. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle 2 minutes.
8. Do the VTEC TEST in the INSPECTION MENU with the HDS.
9. Check the oil pressure.
   1. Does the oil pressure increase to at least 30 kPa (0.3 kgf/cm ²  , 4.3 psi)? 
   2. YES  - Replace the EOP sensor (see EOP SENSOR REMOVAL/INSTALLATION  ), then go to step 10.
   3. NO  - Replace the rocker arm oil control solenoid (VTEC solenoid valve) (see ROCKER ARM OIL CONTROL SOLENOID (VTEC SOLENOID VALVE) FILTER REPLACEMENT  ), then go to step 10.
10. Turn the ignition switch OFF.
11. Reconnect all connectors.
12. Turn the ignition switch 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 above 167°F (75°C)
    • A/T in D position
    • Engine speed at 1,500-3,000 rpm
16. Check for Temporary DTCs or DTCs with the HDS.
    1. Are any Temporary DTCs or DTCs indicated? 
    2. YES  - If DTC P2646 is indicated, check for poor connections or loose terminals at the rocker arm oil control solenoid (VTEC solenoid valve), the EOP sensor, and the PCM, then go to step  1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
    3. NO  - Go to step 17.
17. Monitor the OBD STATUS for DTC P2646 in the DTCs MENU with the HDS.
    1. Does the screen indicate PASSED? 
    2. YES  - Troubleshooting is complete.
    3. NO  - If the screen indicates FAILED, check for poor connections or loose terminals at the EOP sensor and the PCM, then go to step  1 and recheck. If the screen indicates NOT COMPLETED, go to step  15 and recheck.