DTC P2647
DTC P2647: Rocker Arm Oil Pressure Switch A (Bank 1) Circuit High Voltage
General Description
| Mode | PCM sends command to the rocker arm oil control solenoid | Rocker arm oil pressure switch (detected oil pressure) | ||||
|---|---|---|---|---|---|---|
| Solenoid A (Bank 1) | Solenoid B (Bank 1) | Solenoid A (Bank 2) | Switch A (Bank 1) | Switch B (Bank 1) | Switch A (Bank 2) | |
| 6 Cylinder Mode (Low VTEC Range) | OFF | OFF | OFF | ON (low) | OFF (low) | ON (low) |
| Mode | PCM sends command to the rocker arm oil control solenoid | Rocker arm oil pressure switch (detected oil pressure) | ||||
|---|---|---|---|---|---|---|
| Solenoid A (Bank 1) | Solenoid B (Bank 1) | Solenoid A (Bank 2) | Switch A (Bank 1) | Switch B (Bank 1) | Switch A (Bank 2) | |
| 6 Cylinder Mode (High VTEC Range) | ON | OFF | ON | OFF (high) | OFF (low) | OFF (high) |
| 3 Cylinder Mode (3 Cylinders are paused) | OFF | ON | OFF | ON (low) | ON (high) | ON (low) |
The VTEC system activates the rocker arm oil control solenoid A (bank 1) with 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. The PCM monitors oil pressure in the hydraulic circuit of the VTEC mechanism using the rocker arm oil pressure switch A (bank 1) downstream of the rocker arm oil control solenoid A (bank 1). If there is a difference between the oil pressure condition in the hydraulic circuit determined by the PCM command and the oil pressure condition determined by the status of the rocker arm oil pressure switch A (bank 1), the system is considered faulty, and a DTC is stored.
Monitor Execution, Sequence, Duration, DTC Type, OBD Status
| Execution | Once per driving cycle |
| Sequence | None |
| Duration | 7.0 seconds or more |
| DTC Type | One drive cycle, MIL on |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| 12 volt battery voltage [BATTERY] | 10.5 V | - |
| Other | At idle | |
[ ]: HDS Parameter
Malfunction Threshold
When the rocker arm oil control solenoid A (bank 1) is OFF, the rocker arm oil pressure switch A (bank 1) remains OFF.
| Logic Decision | Rocker Arm Oil Pressure Switch A (Bank 1) | ||
|---|---|---|---|
| ON | OFF | ||
| Rocker Arm Oil Control Solenoid A (Bank 1) Command | ON | Failure (P2646) | Normal |
| OFF | Normal | Failure (P2647) | |
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 A (bank 1) failure
- Rocker arm oil control solenoid A (bank 1) VTSB1 line open
- Rocker arm oil control solenoid A (bank 1) VTSB1 line short
- Rocker arm oil pressure switch A (bank 1) failure
- Rocker arm oil pressure switch A (bank 1) VTMB1 line open
- Rocker arm oil pressure switch A (bank 1) VTMB1 line short
- Oil passage clogged
Confirmation Procedure
Operating Condition
Start the engine, and let it idle for at least 7 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.