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Home >> Toyota >> 2003 >> Matrix Base, FWD, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 12 (Engine Control System Self-Diagnostics - 4-Cylinder) >> 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. Using DVOM, backprobe ECM harness connector and measure voltage between terminal No. 21 (Blue/Black wire) at ECM harness connector E6 and terminal No. 18 (White wire) at ECM harness connector E8. See Figure. Remove fuel tank cap. Voltage should be 3.0-3.6 volts. 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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