Powertrain Control Module (PCM) - 68RFE

P0706-TRANSMISSION RANGE SENSOR RATIONALITY

Special Tools:










For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The T41 (C1), T42 (C2), T3 (C3), T1 (C4), T2 (C5) Signal circuits communicate the shift lever position to the Transmission Control System. Each circuit is terminated at the transmission by a switch (TRS). 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 it own unique combination of closed and open switches. This is called a PRNDL code. There are five switches, therefore: there are many possible combinations of open and closed switches (codes). There are eight valid codes: two for neutral, one for each other gear position (3), and three temporary (transition zone) codes. The remainder of the codes should never occur, these are called invalid codes.

- 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 of a second.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

SHIFT LEVER ERROR CODES






TRS SWITCH STATES






1. CHECK TO SEE IF P0706 DTC IS CURRENT
1. With the scan tool, perform the Shift Lever Position Test.

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.
- Perform the 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Verification Test

2. CHECK THE TRANSMISSION SOLENOID/TRS ASSEMBLY
1. Turn the ignition off to the lock position.
2. Remove the Ignition Switch Feed fuse from the TIPM.

CAUTION: Removal of the Ignition Switch Feed fuse from the TIPM will prevent the vehicle from being started in gear.

WARNING: The Ignition Switch Feed fuse must be removed from the TIPM. Failure to do so can result in possible serious or fatal injury.

3. Install Transmission Simulator.
4. Ignition on, engine not running.
5. With the scan tool, perform the Shift Lever Position Test.
6. When the scan tool instructs you to put the Gear Selector in a particular position, you must do so using the selector switch on the Transmission Simulator.
7. The LED for the gear position in question must be illuminated on the Transmission Simulator prior to pressing "ENTER" on the scan tool.

NOTE: When the scan tool requests the O/D off button be depressed, you must use the TOW/HAUL 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 Signal circuit for future reference.

Did the Shift Lever Position test pass?

Yes

- Remove the Oil Pan and Main Valve Body Assembly. Check for metal debris on top of the Solenoid/TRS Assembly and the manual valve code plate. If debris is present, determine the cause of the debris and repair the transmission as necessary. If no problems are found, replace the Transmission Solenoid/TRS Assembly.
- Perform the 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Verification Test

No

- Go To 3

3. TRS SIGNAL CIRCUIT OPEN
1. Turn the ignition off to the lock position.
2. Disconnect the Transmission Simulator, Miller tool #.
3. Disconnect the PCM C2 harness connector.
4. Measure the resistance of the identified (T1, T2, T3, T41, or T42) TRS Signal circuit, from the Transmission Solenoid/TRS Assembly harness connector to the appropriate terminal of the PCM C2 harness connector.

Is the resistance above 5.0 Ohms?

Yes

- Repair the identified (T41, T42, T3, T1, or T2 (C1-C5) TRS Signal circuit for an open.
- Perform the 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Verification Test

No

- Go To 4

4. TRS SIGNAL CIRCUIT SHORTED TO GROUND
1. Measure the resistance between ground and the identified (T41, T42, T3, T1, or T2 (C1-C5) TRS Signal circuit.

Is the resistance below 5.0 Ohms?

Yes

- Repair the identified (T41, T42, T3, T1, or T2 (C1-C5) TRS Signal circuit for a short to ground.
- Perform the 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Verification Test

No

- Go To 5

5. TRS SIGNAL CIRCUIT SHORTED TO OTHER CIRCUITS
1. Measure the resistance between the identified (T1, T2, T3, T41, or T42) TRS Signal circuit and all other circuits in the Transmission Solenoid/TRS Assembly harness connector.

Is the resistance below 100k Ohms between the identified (T41, T42, T3, T1, or T2 (C1-C5) TRS Signal circuit and any other circuit(s) in the Transmission Solenoid/TRS Assembly harness connector?

Yes

- Repair the identified (T41, T42, T3, T1, or T2 (C1-C5) TRS Signal circuit for a short to other circuit(s).
- Perform the 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Verification Test

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. With the scan tool, perform Quick Learn.
- Perform the 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Verification Test

6. CHECK THE WIRING AND CONNECTORS
1. The conditions necessary to set the DTC are not present at this time.
2. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
3. Wiggle the wiring and connectors while checking for shorted and open circuits.
4. With the scan tool, check the Event Data to help identify the conditions in which the DTC was set.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Verification Test

No

- Test Complete.