DTC 21: VTEC System Malfunction Special Tools Required Oil pressure gauge attachment 07NAJ-P070100 Low pressure gauge 07406-0070001 Hose oil pressure 07ZAJ-S5A0200 NOTE: Information marked with an asterisk (*) applies to D16W9, D16W8 engines. Reset the ECM/PCM (see page 11-168). Check the engine oil level, and refill if necessary. Start the engine. Hold the engine at 3.000 rpm with no load (in Park or neutral) until the radiator fan comes on. Road test the vehicle: Accelerate in M/T, A/T: 2nd gear (CVT: L position) to an engine speed over 4,000 rpm. Hold that engine speed for at least 2 seconds. If DTC 21 is not repeated during the first road test, repeat this test 2 more times. Is the MIL on and does it indicated DTC 21? 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 11-148).

Turn the ignition switch OFF. Disconnect the VTEC solenoid valve 1P (2P)* connector. Check for resistance between the VTEC solenoid valve 1P (2P)* connector terminal No. 1 and body ground. VTEC SOLENOID VALVE CONNECTOR Terminal side of male terminals Terminal side of male terminals Is there 14-30 ohms? YES - Go to step 10. NO - Replace the VTEC solenoid valve.