DTC P0450: EVAP Control System Pressure Sensor (EVAP-CSPS): Procedure
- Check EVAP-CSPS hose for blockage or poor connection. Clean or repair as necessary. Turn ignition off. Loosen and retighten 2 engine ground bolts. See Figure. Disconnect EVAP-CSPS harness connector. See Fig 1. Inspect connector for water or damage. Repair as necessary. Turn ignition on. Measure voltage between EVAP-CSPS harness connector Brown/White wire and ground. If voltage is about 5 volts, go to next step. If voltage is not about 5 volts, repair open or short in Brown/White wire.
- Turn ignition off. Check continuity of Black wire between EVAP-CSPS harness connector and ground. If continuity does not exist, repair open in Black wire. If continuity exists, disconnect PCM harness connector. See Figure. Check continuity of White wire between EVAP-CSPS harness connector and PCM harness connector terminal No. 92. See Figure. If continuity exists, go to next step. If continuity does not exist, repair open or short in White wire.
- Check EVAP-CPVCV. See DTC P0443: EVAP CANISTER PURGE VOLUME CONTROL VALVE (EVAP-CPVCV) . Replace, if necessary. If EVAP-CPVCV is okay, check EVAP-CVCV. See DTC P0446: EVAP CANISTER VENT CONTROL VALVE (EVAP-CVCV) . Replace, if necessary. If EVAP-CVCV is okay, go to next step.
- Remove EVAP-CSPS from bracket. Reconnect EVAP-CSPS harness connector. Disconnect hose from EVAP-CSPS. Turn ignition on. Measure voltage between ground and PCM harness connector terminal No. 92 by backprobing. See Figure. With no vacuum applied, voltage should be 3.0-3.6 volts. While observing voltmeter, apply 2.76 in. Hg of vacuum to EVAP-CSPS with a hand vacuum pump. Voltage should be .4-.6 volt. Voltage should increase as pressure increases. See Fig 2. Replace EVAP-CSPS if operation is not as specified. If EVAP-CSPS is okay, go to next step.
- Check water separator and hose to EVAP-CVCV for cracks or blockage. Clean or replace as necessary. If water separator and hose are okay, remove EVAP canister with EVAP-CVCV attached. Attempt to drain water from EVAP canister. If water does not drain form EVAP canister, test is complete. If water drains from EVAP canister, weigh EVAP canister with EVAP-CVCV attached. If weight is more than 4.0 lbs. (1.8 kg), replace EVAP canister. If weight is less than 4.0 lbs. (1.8 kg), no problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.
CAUTION:
DO NOT apply more than 5.91 in. Hg of vacuum to EVAP-CSPS.