DTC Troubleshooting: P2646 (22)
DTC P2646:
 Rocker Arm Oil Pressure Switch Circuit Low Voltage
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 level OK?
YES -
Go to Step 2 .
NO -
Adjust the engine oil to the proper level, then go to Step 20 .
  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 rocker arm oil pressure switch, the rocker arm oil control solenoid, and the ECM.■
NO -
Go to Step 5 .
  1. Turn the ignition switch OFF.
  1. Disconnect the rocker arm oil pressure switch 2P connector.
  1. Turn the ignition switch ON (II).
  1. Check the VTEC PRES SW in the DATA LIST with the HDS.
Is SWITCH ON indicated?
YES -
Go to Step 16 .
NO -
Go to Step 9 .
  1. Turn the ignition switch OFF.
  1. Remove the cowl cover and under cowl panel.
  1. Remove the rocker arm oil pressure switch (A), and install the special tools as shown, then install the rocker arm oil pressure switch in the oil pressure gauge attachment (B).
    NOTE: Install the parts in the reverse order of removal with a new O-ring.
  1. Reconnect the rocker arm oil pressure switch 2P connector.
  1. Start the engine.
  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 392 kPa(4.0 kgf/cm 2 , 56.9 psi)?
YES -
Replace the rocker arm oil pressure switch, then go to Step 19 .
NO -
Inspect the VTEC system. If it is OK. replace the rocker arm oil control valve, then go to Step 19 .
  1. Turn the ignition switch OFF.
  1. Disconnect ECM connector C (44P).