If you have a Honda with a P2646 OBDII error code, the ECM does not see the rocker arm oil switch working when the rocker arm oil control solenoid is switched on.
An OBDII error code will be given “P2646: Rocker arm actuator A- Bank 1 Perf. or Stuck off.” or “A Rocker Arm Actuator System Performance or Stuck Off Bank 1.”
Some OBDII scan tools will also give a “VTEC Oil Pressure Switch Circuit Low Voltage.”
There are several fixes, but anything that prevents oil pressure to the rocker arms will cause the system to fail and give a P2646 error code.
3 Causes and Fixes P2646 Error Code in a Honda
- Low or Dirty Oil
- Oil Pressure Switch
- Valve Timing Solenoid
If the oil is old and dirty or low, it can cause a P2646 error.
Low-cost cheap oil filters have also been known to cause issues with some engines.
Check the oil and be sure it is at the correct level and not old and dirty.
A common cause of an intermittent failure in the oil pressure switch.
The onboard computer (ECM) receives information from the oil pressure switch if the system is working correctly.
If the switch fails, it will give the same error as a failed component.
The switch is usually located on the side of the engine and is a low-cost part to replace.
The VTEC Solenoid Spool can also go bad and need to be replaced.
There is also a small filter inside the solenoid that commonly gets clogged up and often needs to be cleaned.
The solenoid is usually located on the firewall of the engine compartment.
Newer Honda’s will have a Variable Timing Solenoid while older cars will have a VTEC Solenoid Spool.
Summary
A Honda with a P2646 is having a problem with oil pressure.
This is a known problem with Honda’s, often with the error comes back after it was thought to be fixed.
All the components in the system will need to be tested or replaced to get the best results.
First, check the oil and be sure it is not low or dirty and needs an oil change.
Next, check or replace the oil pressure switch since this is how the ECM receives data.
The Valve Timing Solenoid with on older cars is called the VTEC Solenoid newer cars; the Variable Timing Solenoid also needs to be tested or replaced.
Both types of solenoids have a small screen inside them that can become clogged and cause an error.
Have you had issues with a Honda Element and a P2646 OBDII error code? Let us know your thoughts below.
I have a 2005 honda element the check engine light came on p2646 I put the complete assembly on it but when I was installing it I broke the oil pressure switch connector I put it on as best I could but it feels loose and the code p2646 came back after installing everything do you think that could be the problem? and i just changed the oil