LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 1997 >> Supra 3.0 D, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Tests W/Codes - Non-Turbo >> Circuit Tests >> DTC P0402: Excessive Exhaust Gas RECIRCULATION (EGR) Flow Detected >> Diagnosis & Repair (Using OBD-II Scan Tool)
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnosis & Repair (Using OBD-II Scan Tool)

  1. Disconnect EGR temperature sensor. Sensor is located on EGR valve assembly. Using ohmmeter, measure resistance between sensor terminals. If resistance is 2500 ohms or more, go to next step. If resistance is less than 2500 ohms, replace sensor.
  2. Check for short circuit in wiring harness between EGR temperature sensor and ECM. See appropriate wiring diagram in WIRING DIAGRAMS - NON-TURBO article. Repair wiring as necessary. If wiring harness is okay, go to next step.
  3. Remove EGR VSV. VSV is located near intake manifold at left front of engine. Using ohmmeter, measure resistance between valve terminals. Resistance should be 39-45 ohms at 68°F (20°C). Measure resistance between each terminal and body of valve. Resistance should be infinite. If resistance is not as specified, replace VSV. If resistance is as specified, go to next step.
  4. Check VSV operation. Apply battery voltage to VSV terminals. Apply air pressure to VSV port "E". Air from port "E" should flow from port "F". See Figure. Remove battery voltage from valve terminals. Air from port "E" should not flow from port "F". Replace VSV as necessary.
  5. If VSV meets all specifications in steps 3) and 4), check for a short circuit in wiring harness between EGR VSV and ECM. See appropriate wiring diagram in WIRING DIAGRAMS - NON-TURBO article. Repair wiring as necessary. If wiring harness is okay, replace ECM and retest.
scientia non olet · About LEMON Manuals