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Home >> Toyota >> 2003 >> Matrix Base, FWD, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 18 (Engine Control System Self-Diagnostics - V8) >> Diagnostic Tests >> DTC P0450: EVAP Pressure Sensor Circuit Or DTC P0451: EVAP Pressure Sensor Range/Performance >> Diagnosis & Repair
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Diagnosis & Repair

WARNING: This page is about a different car, the 2002 Toyota Tundra. However, it is still accessible from the selected car via links, so may be relevant.
  1. Remove glove box and heater duct (if necessary) for access to ECM with electrical connectors still installed on ECM. See Figure. Turn ignition on. Using voltmeter, check voltage between terminals No. 2 (Green/Black wire) and No. 18 (Green/White wire) at ECM electrical connector E6 with all electrical connectors installed on ECM. See Figure. This is the VC and E2 terminals on ECM. Voltage should be 4.5-5.5 volts. If voltage is within specification, go to next step. If voltage is not within specification, replace ECM.
  2. Turn ignition off. Connect voltmeter between terminals No. 18 (Green/White wire) at ECM electrical connector E6 and No. 22 (Red/Green wire) at ECM electrical connector E4 and with all electrical connectors installed on ECM. See Figure. This is the E2 and PTNK terminals on ECM. Disconnect vacuum hose from vapor pressure sensor. See Figure. Connect hand-held vacuum pump to vacuum hose fitting on vapor pressure sensor. Turn ignition on and note voltage reading with no vacuum applied on vapor pressure sensor. Using vacuum pump, apply 1.18 in. Hg of vacuum to vapor pressure sensor and note voltage reading. Voltage should be 2.9-3.7 volts without vacuum applied and .5 volt or less with vacuum applied. If voltage is not within specification, go to next step. If voltage is within specification, replace ECM.
  3. Check for open and short in wiring harness and electrical connectors between vapor pressure sensor and ECM. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, replace vapor pressure sensor. See VAPOR PRESSURE SENSOR under EMISSION SYSTEMS & SUB-SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article. If wiring harness or electrical connector is defective, repair as necessary.
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