Acura RL. Manual - part 99

ENABLE CONDITIONS 

Malfunction Threshold 

The VLBLB 2 voltage is 4.7 V or more for at least 5 seconds. 

Diagnosis Details 

Conditions for illuminating the MIL 

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

Conditions for clearing the MIL 

The MIL will be cleared if the malfunction does not recur during three consecutive trips in which the 
diagnostic runs. 

The MIL, the DTC, and the freeze frame data can be cleared by using the scan tool Clear command or by 
disconnecting the battery. 

DTC P2646 (22): ADVANCED DIAGNOSTICS (L4 ENGINE A/T) 

DTC P2646: ROCKER ARM OIL PRESSURE SWITCH (VTEC OIL PRESSURE SWITCH) 
CIRCUIT LOW VOLTAGE 

Fig. 309: Rocker Arm Oil Pressure Switch (VTEC Oil Pressure Switch) Circuit Diagram (Low 
Voltage) 

ROCKER ARM OIL PRESSURE SWITCH OPERATION CHART 

Condition

 

Ignition switch

ON

No active DTCs

P0155, P2197, P2240, P2241, P2247, P2249, P2254, P2255, P2630

Logic Decision

Rocker Arm Oil Pressure Switch (VTEC Oil 

Pressure Switch)

 

2007 Acura RL 

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

  

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General Description 

The VTEC system activates the rocker arm oil control solenoid (VTEC solenoid valve) by 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 (VTEC oil pressure 
switch) downstream of the rocker arm oil control solenoid (VTEC solenoid valve). If there is a difference 
between the oil pressure condition in the hydraulic circuit that is determined by the PCM command and the 
oil pressure condition that is determined by the status of the rocker arm oil pressure switch (VTEC oil 
pressure switch), the system is considered faulty, and a DTC is stored. 

Monitor Execution, Sequence, Duration, DTC Type, OBD Status 

MONITOR DESCRIPTION CHART 

Enable Conditions 

ENABLE CONDITIONS 

Malfunction Threshold 

When the rocker arm oil control solenoid (VTEC solenoid valve) is ON, the rocker arm oil pressure switch 
(VTEC oil pressure switch) remains ON. 

Confirmation Procedure with the HDS 

Do the VTEC TEST in the INSPECTION MENU with the HDS. 

Driving Pattern 

'ON'

'OFF'

Rocker Arm Oil Control Solenoid (VTEC Solenoid 
Valve) Command 'ON'

Failure

Normal

Rocker Arm Oil Control Solenoid (VTEC Solenoid 
Valve) Command 'OFF'

Normal

Failure

Execution

Once per driving cycle

Sequence

None

Duration

7 seconds or more

DTC Type

One drive cycle, MIL ON

OBD Status

PASSED/FAILED/NOT COMPLETED (STILL TESTING)

Condition

Minimum

Maximum

Engine coolant temperature

50°F (10°C)

-

Engine speed (High lift cam 
operation

4,750 rpm

-

Vehicle speed

7 mph (10 km/h)

-

Battery voltage

10.5 V

-

Gear position

Other than P or N position

No active DTCs

P1109, P2227, P2228, P2229, P2648, P2649

 

2007 Acura RL 

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

  

me 

 

Friday, June 05, 2009 2:32:08 PM

Page 394  © 2005 Mitchell Repair Information Company, LLC. 

1. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the 

radiator fan comes on.  

2. Drive the vehicle in a lower gear at 4,750 rpm or more for at least 7 seconds.  



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

Diagnosis Details 

Conditions for illuminating the MIL 

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

Conditions for clearing the MIL 

The MIL will be cleared if the malfunction does not recur during three consecutive trips in which the 
diagnostic runs. 

The MIL, the DTC, and the freeze frame data can be cleared by using the scan tool Clear command or by 
disconnecting the battery. 

DTC P2647 (22): ADVANCED DIAGNOSTICS (L4 ENGINE A/T) 

DTC P2647: ROCKER ARM OIL PRESSURE SWITCH (VTEC OIL PRESSURE SWITCH) 
CIRCUIT HIGH VOLTAGE 

Fig. 310: Rocker Arm Oil Pressure Switch (VTEC Oil Pressure Switch) Circuit Diagram (High 
Voltage) 

ROCKER ARM OIL PRESSURE SWITCH OPERATION CHART 

Logic Decision

Rocker Arm Oil Pressure Switch (VTEC Oil 

Pressure Switch)

'ON'

'OFF'

Rocker Arm Oil Control Solenoid (VTEC Solenoid 
Valve) Command 'ON'

Failure

Normal

 

2007 Acura RL 

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

  

me 

 

Friday, June 05, 2009 2:32:08 PM

Page 395  © 2005 Mitchell Repair Information Company, LLC. 

General Description 

The VTEC system activates the rocker arm oil control solenoid (VTEC solenoid valve) by 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 (VTEC oil pressure 
switch) downstream of the rocker arm oil control solenoid (VTEC solenoid valve). If there is a difference 
between the oil pressure condition in the hydraulic circuit that is determined by the PCM command and the 
oil pressure condition that is determined by the status of the rocker arm oil pressure switch (VTEC oil 
pressure switch), the system is considered faulty, and a DTC is stored. 

Monitor Execution, Sequence, Duration, DTC Type, OBD Status 

MONITOR DESCRIPTION CHART 

Enable Conditions 

ENABLE CONDITIONS 

Malfunction Threshold 

When the rocker arm oil control solenoid (VTEC solenoid valve) is OFF, the rocker arm oil pressure switch 
(VTEC oil pressure switch) remains OFF. 

Confirmation Procedure with the HDS 

Do the VTEC TEST in the INSPECTION MENU with the HDS. 

Driving Pattern 

Start the engine, and let it idle for at least 7 seconds. 

Diagnosis Details 

Conditions for illuminating the MIL 

When a malfunction is detected, the MIL comes on and the DTC and the freeze frame data are stored in the 

Rocker Arm Oil Control Solenoid (VTEC Solenoid 
Valve) Command 'OFF'

Normal

Failure

Execution

One per driving cycle

Sequence

None

Duration

7 seconds or more

DTC Type

One drive cycle, MIL ON

OBD Status

PASSED/FAILED/NOT COMPLETED (STILL TESTING)

Condition

Minimum

Maximum

Battery voltage

10.5 V

-

No active DTCs

P1109, P2227, P2228, P2229, P2648, P2649

Other

At idle

 

2007 Acura RL 

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

  

me 

 

Friday, June 05, 2009 2:32:08 PM

Page 396  © 2005 Mitchell Repair Information Company, LLC.