P1259 HONDA - VTEC System Malfunction

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3 
Possible causes
- Low engine oil pressure or level
- Open or short circuit condition
- Faulty VTEC oil pressure switch
- Faulty VTEC solenoid
What does this mean?
When is the code detected?
The P1259 is set when there is a problem in the VTEC Oil Pressure Switch circuit or VTEC Solenoid Valve circuit
Possible symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P1259 Honda Description
The VTEC system activates the VTEC solenoid valve by command from the powertrain control module (PCM), and it charges/discharges the hydraulic circuit of the VTEC mechanism that is installed in the valve system to switch valve timing between Low and High. The PCM monitors oil pressure conditions in the hydraulic circuit of the VTEC mechanism according to the VTEC oil pressure switch downstream of the VTEC solenoid valve. If there is a disparity between oil pressure condition in the hydraulic circuit that is determined by the PCM command, and the oil pressure condition that is determined by the status of the VTEC oil pressure switch, the system is considered faulty and a DTC is stored.



Read more: http://www.autocodes.com/p1259_honda.html#ixzz48odkjzGI

Problem: A defective design of the VVT-i oil line is a rubber hose which routes a high pressure flow of hot engine oil outside the engine block.  The rubber deteriorates over time and miles and can unexpectedly break or rupture causing engine oil to rapidly drain from the engine. This can happen anywhere from about 20,000 to over 100,000 miles and can lead to very expensive repairs. Most owners report getting no warning from the from the oil or check engine lights before they realize they have a problem.

Vehicles affected: Any 2005 - 2009 Toyota or Lexus with the 3.5L V6 2GR-FE engine manufactured worldwide prior to April, 2008. 

Manufactuing fix: Replace the defective metal & rubber oil line "assembly" with an all metal oil line. 

Recall fix: Change out faulty rubber hose in the oil line "assembly" with a higher stregnth rubber hose.  The rubber hose was not replaced with an all metal oil line as was done in the manufacturing fix was becasue in some but not all vehicles afftected, the job is very labor intensive if the engine compartment is a "tight fit" which could (but not in all cases) require removal of the power steering pump, sepentine belts, etc depending on how "tight" the engine compartment is.