DTC P2646: VTEC System Stuck OFF

Special Tools Required

Pressure gauge adapter 07NAJ-P07010A
A/T low pressure gauge w/panel 07406-0070301
A/T pressure hose 07406-0020201
A/T pressure hose, 2,210 mm 07MAJ-PY4011A
A/T pressure adapter 07MAJ-PY40120
Oil pressure hose 07ZAJ-S5AA200

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Check the engine oil level.
Is the engine oil level OK?

YES - Go to step 2.

NO - Adjust the engine oil to the proper level, then go to step 12.
Turn the ignition switch ON (II).
Clear the DTC with the HDS.
Do the VTEC TEST in the INSPECTION MENU with the HDS.
Is the result OK?

YES - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the EOP sensor, the rocker arm oil control solenoid, and the ECM/PCM.

NO - Go to step 5.
Turn the ignition switch OFF.
Remove the EOP sensor (A), install the special tools as shown, then attach the EOP sensor to the oil pressure gauge adapter (B).
NOTE: Install the sensor in the reverse order of removal with a new O-ring.

Fig 1: Attaching EOP Sensor To Oil Pressure Gauge Adapter (With Specifications)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle for 2 minutes.
Do the VTEC TEST in the INSPECTION MENU with the HDS.
Check the oil pressure.
Does the oil pressure increase to at least 30 kPa (4.3 psi, 0.3 kgf/cm ² )?

YES - Replace the EOP sensor (see EOP SENSOR REMOVAL/INSTALLATION ), then go to step 10.

NO - Replace the rocker arm oil control valve (see EOP SENSOR REMOVAL/INSTALLATION ), then go to step 10.
Turn the ignition switch OFF.
Reconnect all connectors.
Turn the ignition switch ON (II).
Reset the ECM/PCM with the HDS.
Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).
Test-drive under these conditions:
- Engine coolant temperature (ECT SENSOR 1) above 167°F (75°C)
- A/T in D position (M/T in 3rd gear)
- ENGINE SPEED at 1,100-3,300 rpm
Check for Temporary DTCs or DTCs with the HDS.
Is DTC P2646 indicated?

YES - Check for poor connections or loose terminals at the rocker arm oil control solenoid, the EOP sensor, and the ECM/PCM, then go to step 1.

NO - Go to step 17.
Monitor the OBD STATUS for DTC P2646 in the DTCs MENU with the HDS.
Does the screen Indicate PASSED?

YES - Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 16, go to the indicated DTCs troubleshooting.

NO - If the screen indicates FAILED, check for poor connections or loose terminals at the rocker arm oil control solenoid, the EOP sensor, and the ECM/PCM, then go to step 1. If the screen indicates NOT COMPLETED, go to step 15.