P0755-2C SOLENOID CIRCUIT





Theory of Operation


The Transmission Control System uses six electronically controlled solenoids that allow hydraulic fluid to be applied to various friction elements (clutches), which enables the gear requested. The continuity of each solenoid circuit is periodically tested. Each inactive solenoid is turned on for a few milliseconds, then off. Each active solenoid is turned off for a few milliseconds, then on. This pulsing of voltage to the solenoid causes an inductive spike which can be sensed by the Transmission Control System. If an inductive spike is not sensed by the Transmission Control System during the continuity check, it is tested again. If the test fails three consecutive times, the appropriate Diagnostic Trouble Code (DTC) is set. If the solenoid test is run in response to a gear ratio or pressure switch error, one failure will result in setting the appropriate DTC.



Possible Causes
RELATED DTCS PRESENT
(T219) 2C SOLENOID CONTROL CIRCUIT SHORT TO OTHER CIRCUITS
(T219) 2C SOLENOID CONTROL CIRCUIT OPEN
(T219) 2C SOLENOID CONTROL CIRCUIT SHORT TO GROUND
TRANSMISSION SOLENOID/TRS ASSEMBLY
POWERTRAIN 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 DTCS

With the scan tool, check DTCs.

Are there any TIPM TCM Power Control Circuit or TCM Power Input DTCs present?

Yes


No

2. CHECK TO SEE IF P0755 IS PRESENT

Turn the ignition off to the lock position.
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 personal injury or death.


Install the Transmission Simulator, Miller tool #8333.
Ignition on, engine not running.
With the scan tool, actuate the 2C Solenoid.

Did the 2C Solenoid LED blink on and off on the Transmission Simulator?

Yes


No

3. CHECK THE TRANSMISSION SOLENOID/TRS ASSEMBLY

With the Transmission simulator still connected, continue to actuate the 2C solenoid for 2 minutes.
After 2 minutes of actuation, with the scan tool, stop the actuation and check for transmission DTCs.

Did the DTC P0755 reset during the actuation test?

Yes


No

4. WIGGLE TEST WITH TRANSMISSION SIMULATOR

With the Transmission simulator still connected, continue to actuate the 2C solenoid for another 2 minutes while wiggling the related wiring harness and connectors.
With the scan tool, stop the actuation and check for transmission DTCs.

Did the DTC P0755 reset during the actuation test?

Yes


No

5. CHECK THE (T219) 2C SOLENOID CONTROL CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT



Turn the ignition off to the lock position.
Disconnect the Transmission Simulator, Miller tool #8333.
Disconnect the PCM harness connectors.
Measure the resistance between the (T219) 2C Solenoid Control circuit and all other circuits in the Transmission Solenoid/TRS Assembly harness connector.

Is the resistance below 5.0 ohms between the (T219) 2C Solenoid Control circuit and any other circuit(s) in the Transmission Solenoid/TRS Assembly harness connector?

Yes


No

6. CHECK THE (T219) 2C SOLENOID CONTROL CIRCUIT FOR AN OPEN



Connect Miller tool #8815 to the PCM C4 harness connector.

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.


Measure the resistance of the (T219) 2C Solenoid Control circuit between the Transmission Solenoid/TRS Assembly harness connector and the appropriate terminal of Miller tool #8815.

Is the resistance above 5.0 ohms?

Yes


No

7. CHECK THE (T219) 2C SOLENOID CONTROL CIRCUIT FOR A SHORT TO GROUND



Measure the resistance between ground and the (T219) 2C Solenoid Control circuit.

Is the resistance below 5.0 ohms?

Yes


No