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Home >> Lincoln >> 2018 >> Navigator Select, 4WD >> Repair and Diagnosis >> Steering >> Electronic Steering >> EPAS Guided Routine Testing >> Pinpoint Tests >> Pinpoint Test AV: PSCM DTC U0401 Invalid Data Received From The ECM/PCM A >> Pinpoint Test Purpose

Pinpoint Test Purpose

To direct the diagnosis to the module and associated circuit sending the faulty or unknown information in the messages.

  1. AV1: CHECK THE PSCM DTCS 
    • Ignition ON, engine running.
    • Carry out the PSCM self-test.
    • Is DTC U0401 Invalid Data Received from the ECM/PCM present and active in the PSCM? 
      Yes No
      Go to  AV2. If the PSCM does NOT list DTC U0401 Invalid Data Received from the ECM/PCM, DISCONTINUE this test and REFER to the DTC Chart for diagnostic direction.
  2. AV2: CHECK THE VEHICLE BATTERY AND CHARGING SYSTEM VOLTAGE 
  3. AV3: RECHECK THE PSCM DTCS 
    • Ignition ON, engine OFF.
    • Clear the PSCM DTCs.
    • Ignition OFF.
    • Wait at least 90 seconds for the modules to completely shut off.
    • Ignition ON, engine running.
    • Operate the system.
    • Carry out the PSCM self-test.
    • Is DTC U0401 Invalid Data Received from the ECM/PCM present and active in the PSCM? 
      Yes No
      DIAGNOSE the PCM concern. REFER to ENGINE CONTROLS - INTRODUCTION (EXCEPT DIESEL & HYBRID) or ELECTRONIC ENGINE CONTROLS - 3.5L ECOBOOST (272KW/370PS) . The concern is not present at this time and may have been set due to a low battery state of charge. The test is complete, no further action is required.