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Home >> Toyota >> 2001 >> ECHO 2D Sedan, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self-Diagnostics >> Diagnostic Tests >> DTC P0450: EVAP Pressure Sensor Circuit, Or DTC P0451: EVAP Pressure Sensor Range/Performance >> Diagnosis & Repair
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Diagnosis & Repair

  1. Access ECM behind glove box. See Figure. Turn ignition on. Using DVOM, backprobe ECM harness connector and measure voltage between terminals No. 1 (Red/White wire) and No. 9 (Brown wire) at ECM harness connector E6. See Figure. Voltage should be 4.5-5.5 volts. If voltage is as specified, go to next step. If voltage is not as specified, replace ECM.
  2. Using DVOM, backprobe ECM harness connector and measure voltage between terminals No. 9 (Brown wire) and No. 14 (Black wire) at ECM harness connector E6. Remove fuel tank cap. Turn ignition on. 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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