Honda service new straight from the Honda IN:
Replace VTEC Oil Pressure Switch for DTC P2646, P2647
NOTE: This article applies to ’03–05 Accord L4s,
’03–05 Elements, and ’02–05 CR-Vs.
Got a vehicle in your shop with either of these
DTCs?
• DTC P2646 (VTEC oil pressure switch circuit
low voltage)
• DTC P2647 (VTEC oil pressure switch circuit
high voltage)
Replacing the VTEC oil pressure switch (P/N
37250-PNE-G01, H/C 6737217) usually fixes the
problem. If it doesn’t, then press on with normal
troubleshooting.