DTC P1457: EVAP Control System
- Perform fuel tank pressure test. See DTC P1456: EVAP CONTROL SYSTEM . Repair as necessary. If fuel tank pressure is okay, disconnect vacuum hose from EVAP purge control solenoid valve. Connect vacuum pump to disconnected hose. Connect jumper wire between PCM 32-pin connector terminal No. 6 (Red/Yellow wire) and ground. Turn ignition on. Apply vacuum to hose. If valve holds vacuum, go to next step. If valve does not hold vacuum, EVAP purge control solenoid valve is okay. Go to step 4.
- Turn ignition off. Disconnect EVAP purge control solenoid valve 2-pin connector. Measure continuity between EVAP purge control solenoid valve 2-pin connector terminal No. 1 (Red/Yellow wire) and ground. If continuity is present, go to next step. If continuity is not present, repair open circuit in Red/Yellow wire between EVAP purge control solenoid valve connector terminal No. 1 and PCM 32-pin connector terminal No. 6.
- Turn ignition on. Measure voltage between EVAP by-pass solenoid valve 2-pin connector terminal No. 2 (Black/Yellow wire) and ground. If battery voltage is present, replace EVAP purge control solenoid valve. If battery voltage is not present, repair open circuit in Black/Yellow wire between EVAP purge control solenoid valve terminal No. 2 and 7.5-amp fuse No. 4.
- Disconnect vacuum hose from EVAP 2-way valve. Connect vacuum pump to disconnected hose. Turn ignition on. Apply vacuum to hose. If valve does not hold vacuum, go to next step. If valve holds vacuum, EVAP by-pass solenoid valve/EVAP 2-way valve is okay. Go to step 7.
- Turn ignition off. Disconnect EVAP by-pass solenoid valve 2-pin connector. Measure continuity between EVAP by-pass solenoid valve 2-pin connector terminal No. 2 (Blue/Black wire) and ground. If continuity is present, go to next step. If continuity is not present, replace EVAP by-pass solenoid valve and "O" rings.
- Disconnect PCM 32-pin connector. Measure continuity between EVAP by-pass solenoid valve 2-pin connector terminal No. 2 (Blue/Black wire) and ground. If continuity is present, repair short circuit in Blue/Black wire between PCM 32-pin connector terminal No. 3 and EVAP by-pass solenoid valve terminal No. 2. If continuity is not present, replace PCM.
- Disconnect vacuum hose from EVAP 3-way valve. Connect vacuum pump to disconnected hose. Connect jumper wire between 32-pin PCM connector terminal No. 4 (Orange/Green wire) and ground. Turn ignition on. Apply vacuum to hose. If valve does not hold vacuum, go to next step. If valve holds vacuum, EVAP control canister vent hut valve is okay. Go to step 10.
- Turn ignition off. Disconnect EVAP control canister vent shut valve 2-pin connector. Measure continuity between EVAP control canister vent shut valve 2-pin connector terminal No. 2 (Orange/Green wire) and ground. If continuity is present, go to next step. If continuity is not present, repair open circuit in Orange/Green wire between EVAP control canister vent shut valve connector terminal No. 2 and 32-pin PCM connector terminal No. 4.
- Turn ignition on. Measure voltage between EVAP control canister vent shut valve 2-pin connector terminal No. 1 (Black/Yellow wire) and ground. If battery voltage is present, replace EVAP control canister vent shut valve and "O" ring. If battery voltage is not present, repair open circuit in Black/Yellow wire between EVAP control canister vent shut valve terminal No. 1 and PCM.
- Turn ignition off. Connect 2 "T" fittings into hose between EVAP control canister and EVAP 2-way valve. Connect fuel tank pressure sensor to one "T" fitting and vacuum pump to other "T" fitting. Remove vent hose for EVAP control canister vent shut valve and cap port to seal fresh air vent for EVAP control canister. Turn ignition on. Measure voltage between 32-pin PCM connector terminal No. 29 (Light Blue wire) and 31-pin PCM connector terminal No. 18 (Green/Black wire). Slowly pump vacuum pump every 1-2 seconds. Pump vacuum until voltage drops to about 1.5 volts. Monitor voltage for about 20 seconds. If voltage does not drop to 1.5 volts and hold for at least 20 seconds, go to next step. If voltage drops to 1.5 volts and holds for at least 20 seconds, check EVAP control canister vent shut valve and connections. Repair as necessary.NOTE: Ensure coolant temperature is greater than 95°F (35°C) and vacuum pump does not leak.
- Turn ignition off. Disconnect purge line hose from EVAP control canister. Plug purge line port. Turn ignition on. Measure voltage between 32-pin PCM connector terminal No. 29 (Light Blue wire) and 31-pin PCM connector terminal No. 18 (Green/Black wire). Slowly pump vacuum pump every 1-2 seconds. Pump vacuum until voltage drops to about 1.5 volts. Monitor voltage for about 20 seconds. If voltage does not drop to 1.5 volts and hold for at least 20 seconds, replace EVAP control canister. If voltage drops to 1.5 volts and holds for at least 20 seconds, check EVAP control solenoid valve line and connections. Repair as necessary. If valve line and connections are okay, go to next step.
- Remove fuel filler cap. Remove vapor line from EVAP 2-way valve located on EVAP control canister. Connect vapor line to a "T" fitting between vacuum gauge and vacuum pump. Apply vacuum slowly and continuously while observing gauge. If vacuum stabilizes momentarily at .2-.6 in. Hg, go to next step. If vacuum stabilizes at less than .2 in. Hg or greater than .6 in. Hg, replace valve.
- Move vacuum pump hose from vacuum fitting to pressure fitting. Move vacuum gauge hose from vacuum side to pressure side. Slowly pressurize vapor line while observing gauge. If pressure stabilizes momentarily greater than .3 in. Hg, system is okay. If pressure stabilizes at less than .3 in. Hg, replace valve.