P0957-AUTOSTICK CIRCUIT LOW





For a complete wiring diagram Refer to Section 8W.

Theory of Operation


The AutoStick Switch is located in the Shift Lever Assembly (SLA). The gear requested by the AutoStick selection is then sent over the AutoStick Up/Down sense circuit to the PCM to engage the requested gear. Normal AutoStick® voltages are: Down = 0.71 to 1.11 volts, Up = 2.02 to 2.41 volts.


  • When Monitored:

    Ignition on and engine running and after 0.5 seconds.

  • Set Condition:

    When the monitored AutoStick Up/Down Sense circuit voltage drops below 0.35 volts.


Possible Causes
  
(T5) AUTOSTICK UP/DOWN SENSE CIRCUIT SHORT TO GROUND
  
(T5) AUTOSTICK UP/DOWN SENSE CIRCUIT SHORT TO ANOTHER CIRCUIT
  
SHIFT LEVER ASSEMBLY
  
TRANSMISSION CONTROL MODULE
  

Always perform the 45RFE/545RFE Pre-Diagnostic Troubleshooting Procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)



Diagnostic Test

1.CHECK IF THE DTC IS CURRENT




Does the scan tool AutoStick voltage read below 0.35 volts?

Yes
  • Go To 2


No
  • Go To 5

2.CHECK THE SHIFT LEVER ASSEMBLY






Does the scan tool AutoStick voltage read below 0.35 volts?

Yes
  • Go To 3


No

3.CHECK THE (T5) AUTOSHIFT UP/DOWN SENSE CIRCUIT FOR A SHORT TO GROUND




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 tool #8815 to perform diagnosis.




Is the resistance below 5.0 ohms

Yes


No
  • Go To 4

4.CHECK THE (T5) AUTOSHIFT UP/DOWN SENSE CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT





Is the resistance below 5.0 ohms between the (T5) AutoStick Up/Down Sense circuit and any other circuit(s) in the Shift Lever Assembly harness connector.

Yes


No
  • 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.
  • Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)

5.CHECK THE AUTOSTICK VOLTAGE WHILE SHIFTING





Did the scan tool AutoStick voltage drop below 0.35 volts at any given time?

Yes


No
  • Go To 6

6.CHECK WIRING AND CONNECTORS






Were there any problems found?

Yes


No
  • Test Complete.