4334/ FMI 3 DIESEL EXHAUST FLUID PRESSURE SENSOR CIRCUIT FAILED HIGH

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Description This code sets when the Aftertreatment Control Module (ACM) detects a short to voltage or open on the Diesel Exhaust Fluid (DEF) Pressure Sensor Circuit
Monitored Parameter Diesel Exhaust Fluid (DEF) Pressure Sensor
Typical Enabling Conditions Always Enabled
Monitor Sequence None
Execution Frequency Always Enabled
Typical Duration 2 Seconds
Dash Lamps MIL, CEL
Engine Reaction Derate 25%
Verification Engine Idle (1 minute)

d150275

    1. Connect DiagnosticLink® . Go to step 2.

    1. Turn the ignition ON (Key ON, Engine OFF). Go to step 3.

    1. Check for multiple codes. Are codes SPN 4335/FMI 3 or SPN 3510/FMI 3 also present?
        1. Yes; Go to step 4.

      1. No; Go to step 9.

    1. Turn the ignition OFF. Go to step 5.

    1. Disconnect the DEF air pressure sensor electrical connector. Go to step 6.

    1. Turn the ignition ON (Key ON, Engine OFF). Go to step 7.

    1. Measure the voltage between pin 3 of the DEF pressure sensor connector, harness side and ground. Is the voltage greater than 5 volts?
        1. Yes; repair the short to power on pin 84 of the 120-pin ACM connector. Verify repair.

      1. No; Go to step 8.

    1. Measure the voltage between pin 3 of the DEF pressure sensor connector, harness side and ground. Is the voltage between 4.5 and 5 volts?
        1. Yes; repair the open circuit between pin 2 of the DEF pressure sensor and pin 99 of the 120-pin ACM connector.

      1. No; repair the open circuit between pin 3 of the DEF pressure sensor and pin 84 of the 120-pin ACM connector. Verify repair.

    1. Turn the ignition OFF. Go to step 10.

    1. Disconnect the DEF pressure sensor. Measure the voltage between pin 3 of the DEF pressure sensor connector, harness side and ground. Is the voltage between 4.5 and 5 volts?
        1. Yes; Go to step 11.

      1. No; repair the open between pin 3 of the DEF pressure sensor connector and the circuit splice. Verify repair.

  1. Measure the voltage between pin 2 of the DEF pressure sensor connector, harness side and pin 3 of the DEF pressure sensor connector, harness side. Is the voltage between 4.5 and 5.0 volts?
      1. Yes; replace the DEF pressure sensor. Verify repair.

    1. No; repair the open between pin 2 of the DEF pressure sensor connector and the circuit splice. Verify repair.

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