P0706-TRANSMISSION RANGE SENSOR RATIONALITY





For a complete wiring diagram Refer to Section 8W.

Theory of Operation


The C1 through C4 (T1, T3, T41, and T42) sense circuits communicate the shift lever position to the PCM. Each circuit is terminated at the transmission with a switch. Each switch can be either open or closed, depending on the shift lever position. The PCM can decode this information and determine the shift lever position. Each shift lever position has a certain combination of switches, which will be open and closed, this is called a PRNDL code. There are 4 switches, therefore: there are many possible combinations of open and closed switches (codes). However, there are only 9 valid codes (8 for AutoStick), one for each gear position and three recognized between gear codes. The remainder of the codes should never occur, these are called invalid codes. The following chart shows the normal switch states for each shift lever position.


  • When Monitored:

    Continuously with the ignition on.

  • Set Condition:

    The DTC will set if the controller detects an invalid PRNDL code which lasts for more than 0.042 seconds.


Possible Causes
  
SHIFTER OUT OF ADJUSTMENT
  
TRS SENSE CIRCUIT OPEN
  
TRS SENSE CIRCUIT SHORT TO GROUND
  
TRS SENSE CIRCUIT SHORT TO VOLTAGE
  
METAL DEBRIS IN OIL PAN
  
TRANSMISSION RANGE SENSOR
  
POWERTRAIN CONTROL MODULE
  

Always perform the 42RLE Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)


TRS SWITCH STATES

SLP
  		T42
  		T41
  		T3
  		T1
  
P
  		CLOSED
  		CLOSED
  		CLOSED
  		OPEN
  
R
  		CLOSED
  		OPEN
  		OPEN
  		OPEN
  
N
  		CLOSED
  		CLOSED
  		OPEN
  		CLOSED
  
OD
  		OPEN
  		OPEN
  		OPEN
  		CLOSED
  
3
  		OPEN
  		OPEN
  		CLOSED
  		OPEN
  
L
  		CLOSED
  		OPEN
  		CLOSED
  		CLOSED
  



Diagnostic Test

1.CHECK TO SEE IF P0706 DTC IS CURRENT



Select the test outcome from the following:

Test passes:
  • Go To 6


Test fails with Error Code:
  • Go To 2


Test fails without Error Code:
  • Perform the Gearshift Adjustment Procedure per the Service Information.
  • Perform the PRNDL Fault Clearing Procedure – Go To 7

2.CHECK THE TRANSMISSION RANGE SENSOR (TRS)



CAUTION: Removal of the Starter Relay will prevent the vehicle from being started in gear.


WARNING: The Starter Relay must be removed from the PDC. Failure to do so can result in personal injury or death.


NOTE: Failure to remove the Starter Relay can cause a Transmission - No Response condition.







NOTE: When the scan tool requests the O/D off button be depressed, you must use the O/D OFF button in the vehicle or you will fail the Shift Lever Position Test with an error code 11 or OD-TOW/HALL STUCK OPEN.


NOTE: If the Shift Lever Position test fails, make sure to note the identification of the TRS Sense circuit for future reference.



Did the Shift Lever Position test pass?

Yes
  • Remove the Oil Pan and Main Valve Body Assembly per the Service Information. Check for metal debris on top of the TRS Assembly. If debris is present, determine the cause of the debris and repair the transmission as necessary. If no problems are found, replace the Transmission Range Sensor (TRS) per the Service Information.
  • Perform the PRNDL Fault Clearing Procedure – Go To 7


No
  • Go To 3

3.TRS SENSE CIRCUIT OPEN




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 above 5.0 ohms?

Yes
  • Repair the identified (T1, T3, T41, or T42) TRS Sense circuit for an open.
  • Perform the PRNDL Fault Clearing Procedure – Go To 7


No
  • Go To 4

4.TRS SENSE CIRCUIT SHORT TO GROUND



Is the resistance below 5.0 ohms?

Yes
  • Repair the identified (T1, T3, T41, or T42) TRS Sense circuit for a short to ground.
  • Perform the PRNDL Fault Clearing Procedure – Go To 7


No
  • Go To 5

5.TRS SENSE CIRCUIT SHORT TO OTHER CIRCUITS



Is the resistance below 100k ohms between the identified (T1, T3, T41, or T42) TRS Sense circuit and any other circuit(s) in the Transmission Range Sensor (TRS) harness connector?

Yes
  • Repair the identified (T1, T3, T41, or T42) TRS Sense circuit for a short to other circuit(s).
  • Perform the PRNDL Fault Clearing Procedure – Go To 7


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 and program the PCM per the Service Information. With the scan tool, perform QUICK LEARN.
  • Perform the PRNDL Fault Clearing Procedure – Go To 7

6.INTERMITTENT WIRING AND CONNECTORS






Were there any problems found?

Yes
  • Repair as necessary.
  • Perform the PRNDL Fault Clearing Procedure – Go To 7


No
  • Test Complete.

7.PRNDL FAULT CLEARING PROCEDURE




NOTE: Vehicle must remain in Overdrive for at least 3.0 seconds.



NOTE: If all the PRNDL lights box individually then the error was cleared.






Does the DTC P0706 reset, or do all the PRNDL indicators remain boxed in park or neutral?

Yes
  • Return to the symptom list and perform diagnostics for P0706.
  • Go To 1


No