DTC Troubleshooting: P2646 (22)
DTC P2646:
 VTEC System Stuck OFF
Special Tools Required

Oil pressure gauge attachment
 07NAJ-P070100

Low pressure gauge
 07406-0070002

Oil pressure hose
 07ZAJ-S5A0200
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
  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 .
  1. Turn the ignition switch ON (II).
  1. Clear the DTC with the HDS.
  1. 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 EOP sensor, the rocker arm oil control solenoid, and the ECM.■
NO -
Go to Step 5 .
  1. Turn the ignition switch OFF.
  1. Remove the EOP sensor (A), install the special tools as shown, then install the EOP sensor in the oil pressure gauge attachment (B).
    NOTE: Install the parts in the reverse order of removal with a new O-ring.
  1. Start the engine. Hold the engine speed at 3,000 rpm (min −1 ) without load (in neutral) until the radiator fan comes on, then let it idle for 2 minutes.
  1. Do the VTEC TEST in the INSPECTION MENU with the HDS.
  1. 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 EOP sensor, then go to Step 10 .
NO -
Replace the rocker arm oil control valve, then go to Step 10 .
  1. Turn the ignition switch OFF.
  1. Reconnect all connectors.
  1. Turn the ignition switch ON (II).
  1. Reset the ECM with the HDS.
  1. Do the ECM idle learn procedure.
  1. Test-drive under these conditions:
    • Engine coolant temperature (ECT SENSOR 1) above 75 °C (167 °F)
    • Transmission in 3rd gear
    • Engine speed between 1,100−3,300 rpm (min −1 )
  1. 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 EOP sensor, and the ECM, then go to Step 1 .
NO -
Go to Step 17 .
  1. 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, the EOP sensor, and the ECM, then go to Step 1 . If the screen indicates NOT COMPLETED, go to Step 15 .