DTC P2656
DTC P2656: Rocker Arm Oil Pressure Switch A (Bank 2) Circuit Low 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 2) 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 2) downstream of the rocker arm oil control solenoid A (bank 2). 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 2), 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 | 3.0 seconds or more |
| DTC Type | One drive cycle, MIL on |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Engine Coolant temperature [ECT SENSOR 1] | 50 °F (10 °C) | - |
| Engine speed [ENGINE SPEED]* | 5, 350 rpm | - |
| Vehicle speed [VEHICLE SPEED] | 6.2 mph (10 km/h) | - |
| 12 volt battery voltage [BATTERY] | 10.5 V | - |
| Shift position | Other than P or N | |
*: Variable that is depending on the engine load.
[ ]: HDS Parameter
Malfunction Threshold
When the rocker arm oil control solenoid A (bank 2) is ON, the rocker arm oil pressure switch A (bank 2) remains ON.
| Logic Decision | Rocker Arm Oil Pressure Switch A (Bank 2) | ||
|---|---|---|---|
| ON | OFF | ||
| Rocker Arm Oil Control Solenoid A (Bank 2) Command | ON | Failure (P2656) | Normal |
| OFF | Normal | Failure (P2657) | |
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 2) failure
- Rocker arm oil control solenoid A (bank 2) VTSB2 line open
- Rocker arm oil control solenoid A (bank 2) VTSB2 line short
- Rocker arm oil pressure switch A (bank 2) failure
- Rocker arm oil pressure switch A (bank 2) VTMB2 line open
- Rocker arm oil pressure switch A (bank 2) VTMB2 line short
- Oil passage clogged
Confirmation Procedure
Operating Condition
- 1.
Start the engine. Hold the engine speed [ENGINE SPEED] at 3, 000 rpm without load (in P or N) until the radiator fan comes on.
- 2.
Drive the vehicle at an engine speed [ENGINE SPEED] 5, 350 rpm or more for at least 3 seconds
- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.
With the HDS
Select the VTEC+VCM TEST in the INSPECTION MENU with the HDS, then select the VEB VTEC TEST with the HDS.
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.