AS68RC Automatic Transmission
P0706-TRANSMISSION RANGE SENSOR RATIONALITY
For a complete wiring diagram Refer to Diagrams/Electrical.
Theory of Operation
The Transmission Range Sensor (TRS) is a multiple position selector switch which changes the signal path by redirecting a 12-volt signal source to seven different TRS signal circuits (P, R, N, D, 3, 2, 1) and also houses a Park/Neutral (P/N) switch circuit. These circuits are monitored by the Transmission Control Module and used in conjunction with various pressure switches to validate proper operation of the transmission and diagnose any possible problem. In a normal operating mode, pressure switch 8, is in an "Off" state in P, R, or N. and in an "On" state in any forward gear (engine running).
Condition One:
When Monitored:
- Continuously with the Ignition on and the engine running.
Set Condition:
- Pressure switch 8 is "On" in Park or Neutral lever positions for the period of 50 ms or greater.
Condition Two:
When Monitored:
- Continuously with the Ignition on and the engine running.
Set Condition:
- Pressure Switch 8 is "On" in P, R, or N for the period of 500 ms or greater.
Condition Three:
When Monitored:
- Ignition on, engine running with a engine speed greater than 550 rpm.
Set Condition:
- Pressure Switch 8 is "Off" in D, 3, 2, or 1 for the period of 7.0 seconds for 2 consecutive tests.
Condition Four:
When Monitored:
- Ignition on.
Set Condition:
- Shift Lever is reading other than Park or Neutral during the first 50 ms of startup.
Always perform the AS68RC Pre-Diagnostic Troubleshooting procedure before proceeding. AS68RC - Pre-Diagnostic Troubleshooting Procedure
Diagnostic Test
1. CHECK IF DTC IS CURRENT
NOTE: This DTC may set if the Transmission Range Sensor has been replaced or reinstalled and not properly adjusted (calibrated). Make sure the TRS is properly adjusted before attempting to perform this diagnostic procedure. If the TRS was improperly adjusted, adjust as necessary and perform AS68RC VERIFICATION TEST AS68RC Transmission Verification Test
Ignition on, engine not running.
With the scan tool, read Transmission DTCs.
Is the status Active or is the Starts Since Set counter 2 or less for this DTC?
Yes
- Go To 2
No
- Go To 7
2. CHECK PRESSURE SWITCH 8 READING ON THE SCAN TOOL
Ignition on, engine not running.
With the scan tool, monitor the Pressure Switch 8 state (On-Off) in the next step.
Move the shift lever to each of the shift lever positions (P, R, N, D, 3, 2, and 1).
Does the Pressure Switch 8 read "On" in all shift positions?
Yes
- Go To 3
No
- Go To 5
3. CHECK THE PRESSURE SWITCH 8
Turn the ignition off to the lock position.
Disconnect the Transmission Solenoid C1 harness connector.
Ignition on, engine not running.
With the scan tool, read the Pressure Switch 8 state (On-Off).
Does the Pressure Switch 8 state read as "On"?
Yes
- Go To 4
No
- Inspect the transmission internal wiring from the Transmission Solenoid C1 connector to the Pressure Switch 8 harness connector and repair or replace as necessary. If no problems are found, replace the Pressure Switch 8.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test
4. CHECK THE (T807) PRESSURE SIGNAL 8 CIRCUIT FOR A SHORT TO GROUND
Turn the ignition off to the lock position.
Disconnect the TCM C3 harness connector.
Ignition on, engine not running.
With the scan tool, read the Pressure Switch 8 state (On-Off).
Does the Pressure Switch 8 state read as "On"?
Yes
- Using the schematics as a guide, check the Transmission Control Module (TCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. Check for Service Information Tune-ups or Service Bulletins for any possible causes that may apply. If no problems are found, replace and program the TCM.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test
No
- Repair the (T807) Pressure Signal 8 circuit for a short to ground.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test
5. COMPARE PRESSURE SWITCH 8 STATE TO SHIFT LEVER POSITION
With the scan tool, monitor the Pressure Switch 8 state (On-Off) in the following step(s).
CAUTION: Apply the parking brake.
Start the engine and with the brakes firmly applied, move the shift lever to each of the shift lever positions (P, R, N, D, 3, 2, 1) and record your findings.
Select the answer that best describes your readings:
Pressure Switch 8 reads "On" in P, R, or N.
- This is an indication of a hydraulic leak into the Pressure Solenoid 8 passage. Inspect the Valve Body and control valves for internal hydraulic leakage, sticking, scored etc. and repair or replace as necessary.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test
Pressure Switch 8 reads "Off" in D, 3, 2, and/or 1.
- Go To 6
6. CHECK THE (T807) PRESSURE SIGNAL 8 CIRCUIT FOR AN OPEN
Turn the ignition off to the lock position.
Disconnect the TCM C3 harness connector.
Disconnect the Transmission Solenoid C1 harness connector.
Measure the resistance of the (T807) Pressure Signal 8 circuit between the TCM C3 harness connector and Transmission Solenoid C1 harness connector.
Is the resistance above 5.0 ohms?
Yes
- Repair the (T807) Pressure Signal 8 circuit for an open.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test
No
- Inspect the transmission internal wiring from the Transmission Solenoid C1 connector to the Pressure Switch 8 harness connector and repair or replace as necessary. If no problems are found, replace the Pressure Switch 8.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test
7. CHECK 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.
Check for any Service Bulletins that may apply.
Were there any problems found?
Yes
- Repair as necessary.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test
No
- Test Complete.