Inspection Procedure

HINT:

• If DTC P0441 (purge flow), P0446 (CCV), P2418 (pressure switching valve), P0451 (evaporative pressure sensor), P0452 (evaporative pressure sensor low input), or P0453 (evaporative pressure sensor low input) is output after DTC P0442 or P0456, first troubleshoot DTC P0441, P0446, P2418, P0451, P0452 or P0453. If no malfunction is detected, troubleshoot DTC P0442 or P0456 next.
• If different DTCs related to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may be open.
• Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
• When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check the EVAP VSV, charcoal canister and vapor pressure sensor.

1. Check voltage between terminals VC and E2 of ECM connector. 

   PREPARATION: 

   1. Remove the glove compartment (see ENGINE CONTROL MODULE (ECM) ).
   2. Turn the ignition switch ON.

   CHECK: 

   Measure the voltage between terminals VC and E2 of the ECM connector.

   OK: 

   Voltage: 4.5 to 5.5 V 

   Fig 1: Identifying Terminals VC & E2 Of ECM Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. NG: Replace ECM (see  ENGINE CONTROL MODULE (ECM)  ). 
   2. OK: Go To Next Step 
2. Check voltage between terminals PTNK and E2 of ECM connectors. 

   PREPARATION: 

   1. Remove the glove compartment (see ENGINE CONTROL MODULE (ECM) ).
   2. Turn the ignition switch ON.

   CHECK: 

   Measure the voltage between terminals PTNK and E2 of the ECM connectors.

   1. Disconnect the vacuum hose from the vapor pressure sensor.
   2. Using the MITYVAC (hand-held vacuum pump), apply a vacuum of 4.0 kPa (30 mmHg, 1.18 in.Hg) to the vapor pressure sensor.
   NOTE: The vacuum applied to the vapor pressure sensor must be less than 66.7 kPa (500 mmHg, 19.7 in.Hg).

   OK: 

   1. Voltage: 2.9 to 3.7 V 
   2. Voltage: 0.5 V or less 
   3. A consecutive waveform presents. 
   Fig 2: Disconnecting Vacuum Hose From Vapor Pressure Sensor

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. OK: Check for intermittent problems (see  PRE-CHECK  ). 
   2. NG: Go To Next Step 
3. Check for open and short in wire harness between vapor pressure sensor and ECM (see  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 
   1. NG: Repair or replace harness and connector. 
   2. OK: Replace vapor pressure sensor.