DTC P2649

DTC P2649:  Rocker Arm Oil Control Solenoid Circuit High Voltage

General Description 

Courtesy of HONDA, U.S.A., INC.

The VTEC system activates the rocker arm oil control solenoid by a command from the powertrain control module (PCM), and it charges/discharges the hydraulic circuit of the VTEC mechanism that switches valve timing between low and high. If the return signal is ON (high) when the PCM outputs the OFF (low) signal to the rocker arm oil control solenoid, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type 

Execution	Continuous
Sequence	None
Duration	2.0 seconds or more
DTC Type	One drive cycle, MIL on

Enable Conditions 

Condition	Minimum	Maximum
12 volt battery voltage [BATTERY]	10.0 V	-

[ ]: HDS Parameter

Malfunction Threshold 

The return signal is ON (high) for at least 2.0 seconds when the PCM outputs the OFF (low) signal to the rocker arm oil control solenoid.

Possible Cause 

NOTE:  The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.

• Rocker arm oil control solenoid VT SOL line open
• Rocker arm oil control solenoid failure
• Rocker arm oil control solenoid ground line open
• PCM internal circuit failure

Confirmation Procedure 

Operating Condition 

• Start the engine. Hold the engine speed at 3, 000 rpm without load (CVT in P or N, M/T in neutral) until the radiator fan comes on.
• Let the engine idle for at least 2 seconds.

With the HDS 

None.

Diagnosis Details 

Conditions for setting the DTC 

When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM memory.

Conditions for clearing the DTC 

The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the 12 volt battery.