DTC Advanced Diagnostics: P2649
DTC P2649: Rocker Arm Oil Control Solenoid Circuit High Voltage
General Description
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
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 VTS line open
- Rocker arm oil control solenoid ground line open
- Rocker arm oil control solenoid failure
- PCM internal circuit failure
Confirmation Procedure
Operating Condition
Start the engine, and let it idle for at least 2 seconds.
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, the freeze data, and the on-board snapshot 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, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.