2007 honda odyssey rocker arm oil pressure switch

We have noticed an increase in oil pressure switch-related problems with late-model Honda vehicles recently. Two switches that seem to be consistently problematic are the rocker arm oil pressure switch and the engine oil pressure switch. Each exhibits a unique set of symptoms, but the fix is the same for both: replace it.

Rocker Arm Oil Pressure Switch

If the vehicle’s malfunction indicator lamp (MIL) is on and diagnostic trouble codes (DTC) P3400 (VPS Stuck Off Bank 1) and/or P3497 (VPS Stuck Off Bank 2) are present, Honda recommends that one or both of the rocker arm oil pressure switches be replaced.

The following models are included:
2008-’12 Accord, 2 & 4-door, V6, A/T
2010-’12 Crosstour, 2WD, V6
2010-’12 Crosstour, 4WD, V6
2008-’11 – Odyssey EX-L/Touring
2012 Odyssey
2009-’12 Pilot, 2WD
2009-’11 Pilot, 2WD
2012 Pilot 4WD

The front and/or rear rocker arm oil pressure switch may fail intermittently. Be sure to check the wiring and connectors from the engine control module (ECM) to each of the switches and the grounds. If all test results are good, the switches are at fault. Note: You may not be able to duplicate symptoms after clearing the DTC(s).

Diagnosis

1. Check the engine oil level on the dipstick.
2. If the engine oil level is below the end of the dipstick (there is no oil on the dipstick), the low engine oil level is likely causing the DTCs. Continue with excessive oil consumption troubleshooting.
3. If the engine oil level is on the dipstick (it may be low, but there is oil on the dipstick), go to the repair procedure.

Repair Procedure

1. Remove the engine cover. Remove the appropriate rocker arm oil pressure switch, depending on which DTC is stored (Fig. 1).
• P3400 – Replace the Bank 1 rear rocker arm oil pressure switch.
• P3497 – Replace the Bank 2 front rocker arm oil pressure switch.
2. Install the new rocker arm oil pressure switch with a new O-ring. Torque each to 16 ft.-lbs. (22 Nm).
3. Reinstall the engine cover.
4. Clear the DTC(s) with a scan tool. Test drive the vehicle to verify the problem has been resolved.

Engine Oil Pressure Switch

With correct engine oil level, a “Check Engine Oil Level” message may appear on the MID or the navigation screen. The “Low Oil Pressure” indicator on the instrument panel may also be on. After verifying the wiring and connectors are in good condition, replace the oil pressure switch.

The following models are included:
2008-’10 Accord, V6, 2-door with M/T
2009-’10 Odyssey, LX and EX
2009-’11 Ridgeline

Repair Procedure

1. Start the engine. Turn the steering wheel fully to the right and then shut off the engine.
2. Raise the vehicle on a lift. Make sure it’s securely supported.
3. On an Accord, remove the front sub-frame middle mount (Fig. 2).
4. For easier removal of the engine oil pressure switch, disconnect the rocker arm oil pressure switch connector (Fig. 3).
5. Disconnect the engine oil pressure switch connector, and then remove the switch. Clean the area around the switch hole.
6. Apply a very thin layer of liquid gasket to the threads of the new switch. Install a new O-ring, then install the switch and torque it to 13 ft.-lbs. (18 Nm).
7. Reconnect the engine oil pressure switch connector and the rocker arm oil pressure switch connector.

Reset the maintenance reminder display as follows:

1. Turn the ignition switch to the ON (II) position.
2. Press the select/reset knob repeatedly until the engine oil life indicator is displayed.
3. Press the select/reset knob for about 10 seconds. The engine oil life and the maintenance item code(s) will blink.
4. Press the select/reset knob for another five seconds. The maintenance item code(s) will disappear, and the engine oil life will reset to 100.

Written by the ALLDATA Community Automotive Diagnostic Team, a select group of automotive experts dedicated to helping technicians fix hard-to-repair vehicles. Meet the team by visiting. ©2014 ALLDATA LLC.

P2646 is a common diagnostic trouble code that affects Honda made vehicles, including the Odyssey.  This code indicates that there is an issue with rocker arm oil pressure switch.  The Rocker arm oil pressure switch verifies the correct oil pressure in the Variable Valve Timing (VVT) mechanism, and is often referred to as the VTEC (Variable Valve Timing & Lift Electronic Control) switch.

If your Odyssey getting P2646, one of the most common reasons that it pops up is the wrong weight oil was used during the last oil change, the oil level is low, or the oil is incredibly dirty.  If any of that sounds like it might be the case for you, start by replacing the oil with the proper oil recommended by Honda.

P2646 Symptoms:  Honda Odyssey

P2646 appearing by itself does not usually correspond to any noticeable drivability symptoms.  You may notice a minor dip in performance and fuel mileage.  If the VTC strainer screen is clogged, the engine may die under heavy acceleration.

P2646 Causes:  Honda Odyssey

The VTEC system controls the variable valve timing in your Odyssey.  It does this by activating the VTEC/Rocker arm solenoid.  It uses the Rocker Arm oil pressure switch to monitor the pressure of this system.  When the pressure is lower than the solenoid, the check engine light will come on and you’ll get P2646.

Here’s a great video on diagnosing P2646 from jimthecarguy on YouTube.

Here are the most common causes for P2646:

• Wrong Oil– If you are unsure of the oil weight used in your Odyssey’s last oil change, this would be a great place to start.  Even if you are sure of the oil weight, take a look at the dipstick.  Make sure that it doesn’t look milky.  If it does look milky, you could have some coolant leaking into the oil pan.  That’s usually caused by a leaking head gasket.  This would hurt the oil’s viscosity and trigger the P2646. 
• Low Oil– If the dipstick is not registering oil at all, it may be too low for the VTEC system to function properly.
• Wiring Issue– P2646 indicates that the voltage from the VTEC/Rocker oil pressure switch is low.  This means that a wiring issue very well could be at fault.  Take a look at the wiring harness where it plugs into this switch.  Make sure that it is undamaged and securely plugged in.  Trace the wiring back and see if it is damaged anywhere. 
• Bad VTEC/Rocker Oil Pressure Switch– After looking at the oil and making sure that it’s ok, and checking the electrical connection, replacing the switch is the next thing to try.  On most Honda made vehicles they aren’t that hard to get to.  And, they aren’t that expensive.  There are many technical service bulletins on Honda made vehicles for this switch.

Odyssey P2646 Conclusion

Good luck diagnosing P2646 in your Honda Odyssey.  If there is anything that you would like to add that could help someone else with this code, please leave a comment below.  Thank you.

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