LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 1995 >> Tercel Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> Diagnostic Testing >> Code P0402 - Excessive Exhaust Gas RECIRCULATION (EGR) Flow Detected >> Diagnosis & Repair (Toyota Scan Tester ONLY)
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnosis & Repair (Toyota Scan Tester ONLY)

  1. Inspect EGR vacuum hoses. Replace as needed. Inspect EGR valve. See the SYSTEM/COMPONENT TESTS article. Inspect EGR VSV. On scan tester, select active test mode. Check operation of VSV when activated by scan tester. VSV is located on cylinder head below EGR vacuum modulator.
  2. Start and run engine. With system in OFF mode, air should flow through valve. With system in ON mode, air should not flow through valve. If valve operates correctly, go to step 4). If valve does NOT operate correctly, go to next step.
  3. Remove EGR VSV. Using ohmmeter, measure resistance between valve terminals. Resistance should be 33-39 ohms at 68°F (20°C). Measure resistance between each terminal and body of valve. Resistance should be infinite. Replace VSV as needed.
  4. Check VSV operation. Apply battery voltage to valve terminals. Air should flow through valve. Remove battery voltage from valve terminals. Air should NOT pass through valve. Replace as needed.
  5. If valve meets all specifications in steps 3) and 4), inspect circuits for short between EGR VSV and ECM. See wiring diagram in the WIRING DIAGRAMS article. Repair as needed.
  6. Inspect EGR vacuum modulator. See procedures in the SYSTEM/COMPONENT TESTS article. Replace as needed. Inspect MAP sensor. See the SYSTEM/COMPONENT TESTS article. Replace as needed. If sensor is okay, replace ECM and retest.
scientia non olet · About LEMON Manuals