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Home >> Toyota >> 2001 >> 4Runner Base >> 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. Remove glove box for access to ECM with electrical connectors still installed on ECM. See Figure. Turn ignition on. Using voltmeter, check voltage between terminals No. 11 (Blue/Black wire) and No. 25 (Green/Black wire) at ECM electrical connector E9 with all electrical connectors installed on ECM. See Figure. This is the E2 and VC 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. 11 (Blue/Black wire) and No. 24 (Yellow wire) at ECM electrical connector E9 with all electrical connectors installed on ECM. See Figure. This is the E2 and PTNK terminals on ECM. Remove fuel tank cap. Turn ignition on and note voltage. Voltage should be 3.3 volts. 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. Vapor pressure sensor is located on top of fuel pump assembly on top of fuel tank and contains a Black 3-pin electrical connector with Green/Black, Yellow and Blue/Black wires. See Figure. 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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