DTC P2648

DTC P2648: Rocker Arm Oil Control Solenoid Circuit Low 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 OFF (low) when the PCM outputs the ON (high) 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 OFF (low) for at least 2.0 seconds when the PCM outputs the ON (high) 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 VTS line short to ground
Rocker arm oil control solenoid failure
PCM internal circuit failure

Confirmation Procedure

Operating Condition

Enter the maintenance mode, then 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, then let it idle.
Drive immediately at a steady engine speed [Engine Speed] 1, 050 RPM or more for at least 2 seconds.

Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.

With the HDS

Do the VTEC TEST in the INSPECTION MENU 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.