DTC P1259: VTEC System Malfunction Special Tools Required Oil pressure gauge attachment 07NAJ-P070100 Low pressure gauge 07406-0070001 Hose oil pressure 07ZAJ-S5A0200 Reset the ECM/PCM (see page 11-312). Check the engine oil level, and refill if necessary. Start the engine. Hold the engine at 3.000 rpm (min-1) with no load (in Park or neutral) until the radiator fan comes on. Road test the vehicle: Accelerate in 1st gear to an engine speed over 4,000 rpm (min-1). Hold that engine speed for at least 2 seconds. If DTC P1259 is not repeated during the first road test, repeat this test 2 more times. Is DTC P1259 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 at the ECM/PCM. Turn the ignition switch OFF. Remove the resonator (see page 11-448).

Disconnect the VTEC oil pressure switch 2P connector. Check for continuity on the VTEC oil pressure switch between the VTEC oil pressure switch 2P connector terminals No. 1 and No. 2. VTEC OIL PRESSURE SWITCH 2P CONNECTOR Terminal side of male terminals Is there continuity? YES - Go to step 9. NO - Replace the VTEC oil pressure switch. Turn the ignition switch ON (II). Measure voltage between the VTEC oil pressure switch 2P connector terminal No. 1 and body ground. VTEC OIL PRESSURE SWITCH HARNESS 2P CONNECTOR Wire side of female terminals Is there battery voltage? YES - Go to step 15. NO - Go to step 11.