DTC P2651

DTC P2651 : Rocker Arm Oil Pressure Switch B (Bank 1) Performance/Stuck off

Special Tools Required

-Pressure Gauge Adapter 07NAJ-P07010A

-A/T Low Pressure Gauge w/Panel 07406-0070301

-A/T Pressure Test Hose 07AAJ-PY4A100

-A/T Pressure Adapter 07MAJ-PY40120

-Oil Pressure Hose 07ZAJ-S5AA200

NOTE: Before you troubleshoot, review the general troubleshooting information - Refer to: How to Troubleshoot the Fuel and Emissions Systems, or How to Troubleshoot the Brake Booster Pressure Monitoring System (2016 2017 2018 2019 2020), or How to Troubleshoot the Fuel and Emissions Systems(With Auto Idle Stop System) (2016), or How to Troubleshoot the A/T System (2014 2015) .

If DTC P2653 and/or P2654 are stored at the same time as DTC P2651, troubleshoot those DTCs first, then recheck for DTC P2651.

DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
P2651 Rocker Arm Oil Pressure Switch B (Bank 1) Performance/Stuck off

DTC (PGM-FI)

Oil level check
-1. Check the engine oil level.

Is the level OK?

YES

Go to step 2.

NO

Go to step 2, and check the result. Then adjust the engine oil to the proper level , and recheck. If the failure is duplicated in step 2, go to step 3.
Problem verification
-1. Turn the vehicle to the ON mode.

- 2. Clear the DTC with the HDS.

- 3. Select the VTEC+VCM TEST in the INSPECTION MENU with the HDS, then select the CDVEB TEST with the HDS.

CDVEB TEST

Does the HDS indicate Normal?

YES

Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at rocker arm oil pressure switch B (Bank 1) and the PCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.

NO

Go to step 3.

Open wire check (VCMSW line)

-1. Turn the vehicle to the OFF (LOCK) mode.

- 2. Disconnect the following connector.

Rocker arm oil pressure switch B (Bank 1) 1P connector - Refer to: Rocker Arm Oil Pressure Switch A (Bank 1) Removal and Installation, or Rocker Arm Oil Pressure Switch B (Bank 1) Removal and Installation, or Rocker Arm Oil Pressure Switch A (Bank 2) Removal and Installation

- 3. Turn the vehicle to the ON mode.

- 4. Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
Test condition	Rocker arm oil pressure switch B (Bank 1): disconnected
Test circuit	VCMSW
Test point 1	Rocker arm oil pressure switch B (Bank 1) 1P connector No. 1 (TAN)
Test point 2	Body ground

Courtesy of HONDA, U.S.A., INC.

Is there any voltage?

YES

Repair an open in the VCMSW wire between PCM (C34) and rocker arm oil pressure switch B (Bank 1).

The VCMSW wire is OK. Go to step 4.

VCM system oil pressure check

-1. Turn the vehicle to the OFF (LOCK) mode.

- 2. Remove rocker arm oil pressure switch B (Bank 1) (A), and attach the special tools as shown, then attach rocker arm oil pressure switch B (Bank 1) to the oil pressure gauge adapter (B).

Courtesy of HONDA, U.S.A., INC.

- 3. Reconnect the following connector.

- 4. Start the engine.

- 5. Select the VTEC+VCM TEST in the INSPECTION MENU with the HDS, then select the CDVEB TEST with the HDS.

CDVEB TEST

Check the oil pressure.

Is the oil pressure 50 kPa (0.5 kgf/cm 2, 7.1 psi) or more?

YES

Inspect the VCM system oil passage. If it is OK, replace the rear rocker arm oil control valve - Refer to: Front Rocker Arm Oil Control Valve Removal and Installation, or Rear Rocker Arm Oil Control Valve Removal and Installation .

Replace the rear rocker arm oil control valve - Refer to: Front Rocker Arm Oil Control Valve Removal and Installation, or Rear Rocker Arm Oil Control Valve Removal and Installation .