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Home >> Toyota >> 2004 >> Matrix Base, FWD, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 16 (Engine Control System Self-Diagnostics - V6) >> 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 Highlander. However, it is still accessible from the selected car via links, so may be relevant.
  1. Access ECM behind glove box. See Figure. Turn ignition on. Using DVOM, backprobe ECM harness connector and measure voltage between terminals No. 2 (Blue/Red wire) and No. 18 (White wire) at ECM harness connector E8. See Figure. If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, replace ECM.
  2. Turn ignition off. Using DVOM, backprobe ECM harness connector and measure voltage between terminal No. 17 (Blue/Black wire) at ECM harness connector E5 and terminal No. 18 (White wire) at ECM harness connector E8. See Figure. Disconnect vacuum hose from vapor pressure sensor. See Figure. Vapor pressure sensor is mounted above fuel tank, near fuel level sensor. Connect a vacuum pump to vapor pressure sensor. Turn ignition on. Voltage should be 2.9-3.7 volts without vacuum applied, and .5 volt or less with 1.18 in. Hg applied. If voltage is not as specified, go to next step. If voltage is as specified, replace ECM.
  3. Check for open or short in wiring between vapor pressure sensor and ECM. See WIRING DIAGRAMS article. If problem exists, repair wiring as necessary. If problem does not exist, replace vapor pressure sensor.
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