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Code 65: Pressure Sensor Signal

NOTE: Refer to illustration for ECU connector and terminal identification. See Figure .
  1. Check for damaged or disconnected pressure sensor hose. Replace hose as necessary. If hose is okay, go to next step.
  2. Start engine. With engine at normal operating temperature, check intake manifold pressure. If manifold vacuum is 15.75-19.69 in. Hg, go to next step. If manifold vacuum is not 15.75-19.69 in. Hg, repair intake system.
  3. Turn ignition off. Disconnect ECU connectors. Measure resistance between pressure sensor connector and ECU connector. See the PRESSURE SENSOR RESISTANCE SPECIFICATIONS (TABLE 2)  table below. If resistance is as specified, go to next step. If resistance is not as specified, repair connector and/or wiring harness as necessary.
    PRESSURE SENSOR RESISTANCE SPECIFICATIONS (TABLE 2)

    Measure Between Terminals Ohms
    No. 1 (1) (F121) & (1) No. 2 (2) Less Than One
    No. 2 (1) (F121) & (1) No. 2 (2) Less Than One
    No. 3 (1) (F121) & (1) No. 1 (2) Less Than One
    No. 2 (3) (F119) & (1) No. 3 (2) Less Than One
    (1) Measure at ECU connector F121.
    (2) Measure resistance at pressure sensor connector. See Figure .
    (3) Measure at ECU connector F119.
  4. Reconnect ECU connectors. Measure resistance between terminals No. 1 and 2 and between terminals No. 3 and 2 of pressure sensor connector. See Figure . If both resistances are infinite, go to next step. If either resistance is not infinite, repair connector and/or wiring harness as necessary.
  5. Turn ignition off. Disconnect pressure sensor connector. Turn ignition on. Measure voltage between terminals No. 2 and 3 of pressure sensor connector. See Figure . If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, replace ECU.
  6. Turn ignition off. Reconnect pressure sensor connector. Turn ignition on. Backprobe ECU connector F121 and measure voltage between terminals No. 1 and 3 and between terminals No. 2 and 3. If both voltage readings are 3.4-3.8 volts, go to next step. If either voltage reading is not 3.4-3.8 volts, replace pressure sensor.
  7. Start engine. With engine idling, backprobe ECU connector F121 and measure voltage between terminals No. 1 and 3 and between terminals No. 2 and 3. If both voltage readings are 1.6-2.1 volts, replace ECU. If either voltage reading is not 1.6-2.1 volts, replace pressure sensor.
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