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Home >> Chrysler >> 2007 >> 300 Base >> Repair and Diagnosis >> Transmission >> Transmission Control Systems >> 42RLE Automatic Transmission - Electrical Diagnostics >> DTC Troubleshooting >> P1794-Speed Sensor Ground Error >> Diagnostic Test

Diagnostic Test

  1. 1) PCM AND WIRING 

    Turn the ignition off to the lock position.

    Remove the Starter Relay.

    CAUTION: Removal of the Starter Relay is to prevent a Transmission, NO RESPONSE, condition and disable the starter.

    Install the Transmission Simulator, Miller tool #8333 and the Electronic Transmission Adapter kit.

    Ignition on, engine not running.

    With the Transmission Simulator, set the "Input/Output Speed" switch to "ON" and the rotary switch to the "3000/1250" position.

    With the scan tool, monitor the Input and Output Speed Sensor readings.

    Does the Input Speed read 3000 RPM and the Output Speed read 1250 RPM, ± 50 RPM? 

    Yes 

    1. Go To  2).

    No 

    1. Go To  3).
  2. 2) (T13) SPEED SENSOR GROUND CIRCUIT OPEN 
    Fig 1: Checking Speed Sensor Ground Circuit
    GC0012622Courtesy of CHRYSLER LLC

    Turn the ignition off to the lock position.

    Disconnect the PCM C4 harness connector.

    Disconnect the Input and Output Speed Sensor harness connectors.

    NOTE: Check connectors - Clean/repair as necessary.
    CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

    Measure the resistance of the (T13) Speed Sensor Ground circuit from the appropriate terminal of special tool #8815 to the Input and Output Speed Sensor harness connectors.

    Is the resistance above 5.0 ohms on either circuit? 

    Yes 

    1. Repair the (T13) Speed Sensor Ground circuit for an open.
    2. Perform 42RLE TRANSMISSION VERIFICATION TEST .

    No 

    1. Using the schematics as a guide, check the Powertrain Control Module (PCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the PCM per the Service Information. With the scan tool PERFORM QUICK LEARN, then program Pinion Factor in the Front Control Module. Refer to REMOVAL .
    2. Perform 42RLE TRANSMISSION VERIFICATION TEST .
  3. 3) INTERMITTENT WIRING AND CONNECTORS 

    The conditions necessary to set the DTC are not present at this time.

    Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.

    Wiggle the wires while checking for shorted and open circuits.

    With the scan tool, check the DTC EVENT DATA to help identify the conditions in which the DTC was set.

    Were there any problems found? 

    Yes 

    1. Repair as necessary.
    2. Perform 42RLE TRANSMISSION VERIFICATION TEST .

    No 

    1. Test Complete.