Canister System Leak Test
- Turn ignition off. Connect 2 "T" fittings and vacuum pump/gauge to hoses between EVAP canister and EVAP 2-way valve as illustrated. See Fig 1. Connect fuel tank pressure (FTP) sensor to one "T" fitting and vacuum pump/gauge to second "T" fitting. See Fig 1. Remove vent hose from EVAP canister vent shut valve and cap open port. See Fig 2. Turn ignition on and go to next step.
- Monitor FTP sensor voltage with a scan tool or backprobe with a DVOM to measure voltage between PCM connector "A" (32-pin connector) terminal No. 29 (Light Green wire) and PCM connector "C" (31-pin connector) terminal No. 18 (Green/Black wire). See Figure and Figure
. Using vacuum pump, slowly apply vacuum every 1-2 seconds until voltage reading drops to about 1.5 volts. Ensure engine coolant temperature is above 95°F (35°C). Monitor voltage for 20 seconds. If voltage does not drop to 1.5 volts and hold for 20 seconds, go to next step. If voltage drops to 1.5 volts and holds for at least 20 seconds, check EVAP canister vent shut valve line and connections.
- Turn ignition off. Disconnect purge hose from EVAP canister and cap open port. See Fig 3. Turn ignition on. Monitor FTP sensor voltage with a scan tool or backprobe with a DVOM to measure voltage between PCM connector "A" (32-pin connector) terminal No. 29 (Light Green wire) and PCM connector "C" (31-pin connector) terminal No. 18 (Green/Black wire). Using vacuum pump, slowly apply vacuum every 1-2 seconds until voltage reading drops to about 1.5 volts. Ensure engine coolant temperature is above 95°F (35°C). Monitor voltage for 20 seconds. If voltage does not drop to 1.5 volts and hold for 20 seconds, replace EVAP canister. If voltage drops to 1.5 volts and holds for at least 20 seconds, check EVAP canister vent shut valve line and connections. If canister vent shut valve line and connections are okay, test EVAP 2-way valve. See SYSTEM & COMPONENT TESTING article. Perform final procedure. See FINAL PROCEDURE .
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Courtesy of AMERICAN HONDA MOTOR CO., INC.