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Home >> Toyota >> 1997 >> RAV4 2D Utility, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Tests W/Codes >> Circuit Tests >> DTC P0450: EVAP Pressure Sensor Malfunction >> Diagnosis & Repair

Diagnosis & Repair

  1. Access ECM behind bottom center of instrument panel, in front of console. Turn ignition on. Backprobing ECM connector, measure voltage between terminals No. 1 (Yellow wire) and No. 9 (Brown wire) at ECM E5 connector. 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 and retest.
  2. Backprobing ECM connector, measure voltage between terminals No. 7 (Blue/Yellow wire) and No. 9 (Brown wire) at ECM E5 connector. Disconnect vacuum hose from vapor pressure sensor. Sensor is located near brake master cylinder. Voltage reading should be as follows:
    • 2.9-3.7 volts with no vacuum applied.
    • 4.2-4.8 volts with .22 psi (1.5 kPa) pressure applied.
    • 1.3-2.1 volts with .59 in. Hg (2.0 kPa) vacuum applied.

    If voltage is as specified, replace ECM and retest. If voltage is not as specified, go to next step.

  3. Check for open or short circuit in wiring harness between vapor pressure sensor and ECM. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair wiring as necessary. If wiring harness is okay, replace vapor pressure sensor.
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