P2646
DTC P2646: VTEC Oil Pressure Switch CircuitLow Voltage - 2005 model
Special Tools Required
^ Pressure gauge adapter 07NAJ-PO7010A
^ A/T low pressure gauge w/panel 07406-0070300
^ A/T pressure hose, 2,210 mm 07MAJ-PY4011A
^ A/T pressure hose adapter 07MAJ-PY40120
1. Do the engine control module (ECM) reset procedure.
2. Start the engine.
3. Warm up the engine to normal operating temperature (cooling fan comes on).
4. Test-drive the vehicle. Accelerate in 1st gear to an engine speed over 4,000 rpm. Hold that engine speed for at least 2 seconds. If DTC P2646 is not repeated during the first test, repeat this test two more times.
Is DTC P2646 indicated?
YES-Go to step 5.
NO-intermittent failure, system is OK at this time. Check for poor connections or loose wires at the VTEC solenoid valve and the ECM.
5. Turn the ignition switch OFF.
6. Remove the VTEC oil pressure switch (A) and install the special tools as shown, then install the VTEC oil pressure switch (A) to the oil pressure gauge adapter (B).
NOTE: Install the part in the reverse order of removal with a new O-ring.
7. Disconnect the VTEC solenoid valve 1P connector.
8. Warm up the engine to normal operating temperature (cooling fan comes on).
9. Attach the battery positive cable to the VTEC solenoid valve terminal.
10. Start the engine and check oil pressure at an engine speed of 3,000 rpm.
Is pressure above 200 kPa (2.0 kgf/cm2, 28 psi)?
YES-Go to step 11.
NO-Inspect the VTEC solenoid valve.
11. Disconnect the VTEC oil pressure switch 2P connector.
12. At the VTEC oil pressure switch side, check for continuity between the VTEC oil pressure switch 2P connector terminals No. 1 and No. 2 in the condition of step 10.
Is there continuity?
YES-Replace the VTEC oil pressure switch.
NO-Go to step 13.
13. Turn the ignition switch OFF.
14. Disconnect the battery terminals from the VTEC solenoid valve terminal connector.
15. Disconnect ECM connector C (31P).
16. Check for continuity between ECM connector terminal C10 and body ground.
Is there continuity?
YES-Repair a short in the wire between the ECM (C10) and the VTEC oil pressure switch.
NO-Go to step 17.
17. Disconnect the ECM connector B (25P).
18. Check for continuity between ECM connector terminal 1312 and body ground.
Is there continuity?
YES-Repair a short in the wire between the ECM (B12) and the VTEC solenoid valve.
NO-Go to step 19.
19. Check for continuity between the VTEC solenoid valve harness 1P connector terminal and the ECM connector terminal B12.
Is there continuity?
YES-Substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.
NO-Repair an open in the wire between the ECM (B12) and the VTEC solenoid valve.