M/T
DTC P1420 - FUEL TANK PRESSURE CONTROL SOLENOID VALVE CIRCUIT HIGH INPUTDTC DETECTING CONDITION:
- Two consecutive driving cycles with fault
CAUTION: After repair or replacement of faulty parts, conduct CLEAR MEMORY MODE and INSPECTION MODE. Refer to How To Clear Diagnostic Trouble Codes.
Wiring Diagram:
WIRING DIAGRAM
10CH1: CHECK OUTPUT SIGNAL FROM ECM.
1. Turn ignition switch to OFF.
2. Connect test mode connector at the lower portion of instrument panel (on the driver's side), to the side of the center console box.
3. Turn ignition switch to ON.
Connector & Terminal - [(B134) No.1(+) - Chassis Ground(-)]:
4. While operating fuel tank pressure control solenoid valve, measure voltage between ECM and chassis ground.
NOTE: Fuel tank pressure control solenoid valve operation can be executed using Subaru Select Monitor. For procedure, refer to "COMPULSORY VALVE OPERATION CHECK MODE".
CHECK: Does voltage change between 0 and 10 V?
YES: Go to step 10CH2.
NO: Even if MIL light up, the circuit has returned to a normal condition at this time. In this case, repair poor contact in ECM connector.
10CH2: CHECK OUTPUT SIGNAL FROM ECM.
1. Turn ignition switch to ON.
Connector & Terminal - [(B134) No.1(+) - Chassis Ground(-)]:
2. Measure voltage between ECM and chassis ground.
CHECK: Is the voltage more than 10 V?
YES: Go to step 10CH4.
NO: Go to step 10CH3.
10CH3: CHECK POOR CONTACT.
Check poor contact in ECM connector.
CHECK: Is there poor contact in ECM connector.
YES: Repair poor contact in ECM connector.
NO: Replace ECM.
10CH4: CHECK HARNESS BETWEEN FUEL TANK PRESSURE CONTROL SOLENOID VALVE AND ECM CONNECTOR.
1. Turn ignition switch to OFF.
2. Disconnect connector from fuel tank pressure control solenoid valve.
3. Turn ignition switch to ON.
Connector & Terminal - [(B134) No.1(+) - Chassis Ground(-)]:
4. Measure voltage between ECM and chassis ground.
CHECK: Is the voltage more than 10 V?
YES: Repair battery short circuit in harness between ECM and fuel tank pressure control solenoid valve connector. After repair, replace ECM.
NO: Go to step 10CH5.
10CH5: CHECK FUEL TANK PRESSURE CONTROL SOLENOID VALVE.
1. Turn ignition switch to OFF.
Terminals [No.1 - No.2]:
2. Measure resistance between fuel tank pressure control solenoid valve terminals.
CHECK: Is the resistance less than 1 Ohm?
YES: Replace fuel tank pressure control solenoid valve and ECM.
NO: Go to step 10CH6.
10CH6: CHECK POOR CONTACT.
Check poor contact in ECM connector.
CHECK: Is there poor contact in ECM connector?
YES: Repair poor contact in ECM connector.
NO: Replace ECM.