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Cold DRIVEABILITY Test 6 - EGR System Check

  1. Disconnect vacuum hose from EGR valve. Connect vacuum gauge to the vacuum hose. Start engine. Slowly increase engine speed. Vacuum reading should be zero with the engine temperature below 70°F (21°C) on 2-Bbl. models and below 50°F (10°C) on 4-Bbl. models. If there is NO vacuum, proceed to COLD DRIVEABILITY TEST 7  .
  2. If there is vacuum, connect voltmeter to the EGR vacuum solenoid (Gray wire) and ground. Observe voltmeter reading. Voltage should be 0-1 volts with the engine temperature below 70°F (21°C) on 2-Bbl. models and below 50°F (10°C) on 4-Bbl. models.
    Fig 1: Voltmeter
    G4183
  3. If voltage is okay, connect voltmeter to EGR vacuum solenoid (Blue wire) and ground. Voltage reading should be within one volt of battery voltage. If voltage reading is okay, replace EGR solenoid. If zero volts, repair wiring to the ignition switch for an open circuit.
    Fig 2: Voltmeter
    G4184
  4. If voltage reading is step 2) is above one volt, turn ignition off. Disconnect computer 12-way connector. Connect a voltmeter to 12-way connector cavity "7" and ground. Turn the ignition switch to the "RUN" position. Voltmeter reading should be within one volt of battery voltage.
    Fig 3: Voltmeter
    G5943
  5. If voltage is within specifications, check terminal in 12-way connector cavity "7" to ensure it is not spread apart causing a poor connection. If connections are okay, replace computer. If there is zero volts, repair wiring to cavity "7" for an open circuit to the EGR vacuum solenoid.