LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lincoln >> 2021 >> Navigator Base, RWD >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Automatic Transmission External Controls >> Diagnosis And Testing >> External Controls >> Pinpoint Tests >> Pinpoint Test I: Internal Module DTCS
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Pinpoint Test I: Internal Module DTCS

  1. Normal Operation and Fault Conditions 

    The GSM performs periodic tests on itself. It sets a DTC if any of the results are outside of normal operating standards.

    DTC Fault Trigger Conditions 

    DTC Description Fault Trigger Condition
    GSM P0605:00 Internal Control Module Read Only Memory (ROM) Error: No Sub Type Information The GSM detected a ROM checksum error.
    GSM P0606:00 Control Module Processor: No Sub Type Information The GSM detected a reset without going through a proper sleep cycle.
    GSM P0607:00 Control Module Performance: No Sub Type Information The GSM detected an early or delayed response of greater than 10 percent of its periodic rate.
    GSM P06B8:00 Internal Control Module Non-Volatile Random Access Memory (NVRAM) Error: No Sub Type Information The GSM detected a RAM checksum error.
    GSM P164E:00 Internal Control Module Transmission Range Select Performance: No Sub Type Information The GSM detected a start up test failure, a program flow monitor failure, an IPC software failure, or a 5V_1_MONITOR failure.

    Possible Sources 

    • Discharged battery/charging system
    • GSM calibration
    • GSM

  2. I1 CHECK THE GSM (GEAR SHIFT MODULE) FOR CONTINUOUS MEMORY DIAGNOSTIC TROUBLE CODES (CMDTCS)

    • Ignition ON.

    • Retrieve all continuous memory diagnostic trouble codes (CMDTCs) from the GSM.

    Is DTC P0562 or P0563 present in the GSM? 

    Yes  RESOLVE those diagnostic trouble codes (DTCs) first.
    No  GO to  I2

  3. I2 PROGRAM THE GSM (GEAR SHIFT MODULE) WITH THE LATEST CALIBRATION

    NOTE: If a GSM self-test is carried out, the driver door must be fully closed and locked. A false P166B DTC may set if the driver door is not fully closed and locked.

    • Ignition ON.

    • Clear all diagnostic trouble codes (DTCs) from the GSM.

    • Road test the vehicle.

    • Ignition OFF.

    • Ignition ON.

    • Using a diagnostic scan tool, carry out the GSM self-test.

    Is DTC P0605, P0606, P0607, P06B8 or P164E present in the GSM? 

    Yes  INSTALL a new GSM. REFER to: Gear Shift Module (GSM)  .
    No  The fault is not present at this time. It may have been caused by a module programming error.
scientia non olet · About LEMON Manuals