Torque Converter Clutch Pressure Control Circuit Low From 2011
P2764 - Torque Converter Clutch Pressure Control Circuit Low
For a complete wiring diagram, refer to.
Theory of Operation
The EMCC VFS Solenoid is used to control the duty cycle of the Torque Converter Clutch (TCC). The PCM monitors the voltage on the EMCC VFS Solenoid Control circuit. If the PCM detects a failure for 2 consecutive trips, the DTC is set.
• When Monitored:
• Battery voltage is greater than 7.0 volts.
• TCC duty cycle is less than 8%.
• Torque converter is not in Lock Up or Partial Lock Up.
• Set Condition:
• The PCM detects the EMCC VFS voltage is below a calibrated threshold for 357 ms.
Always perform the pre-diagnostic troubleshooting procedure before proceeding. Refer to => Non-DTC Based Diagnostics. Pre-Diagnostic Troubleshooting Procedure
Test Step 1 - CHECK IF DTC IS CURRENT
• With the scan tool, view DTCs.
Is the status Active or is the Starts Since Set counter 2 or less for this DTC?
Yes
• Go to Test Step 2
No
• Go to Test Step 8
Test Step 2 - CHECK THE (T16) TRANSMISSION CONTROL OUTPUT OPEN OR HIGH RESISTANCE
• Turn the ignition off to the lock position.
• Disconnect the Transmission Solenoid/TRS Assembly harness connector.
• Ignition on, engine not running.
• Using a scan tool, actuate the TCM relay.
• Using a test light connected to ground, check the (T16) Transmission Control Output circuit.
• The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.
Does the test light illuminate brightly on the (T16) Transmission Control Output circuit?
Yes
• Go to Test Step 3
No
• Repair the (T16) Transmission Control Output circuit for an open or high resistance.
• Perform the Transmission Verification Test. Refer to => Non-DTC Based Diagnostics. Transmission Verification Test
Test Step 3 - CHECK THE (T84) EMCC VFS CONTROL CIRCUIT FOR AN OPEN
• Turn the ignition off to the lock position.
• Disconnect the PCM C4 harness connector.
• Measure the resistance of the (T84) EMCC VFS Control circuit between the Transmission Solenoid/TRS Assembly harness connector and the PCM C4 harness connector.
Is the resistance below 5.0 Ohms?
Yes
• Go to Test Step 4
No
• Repair the (T84) EMCC VFS Control circuit for an open.
• Perform the Transmission Verification Test. Refer to => Non-DTC Based Diagnostics. Transmission Verification Test
Test Step 4 - CHECK THE (T84) EMCC VFS CONTROL CIRCUIT FOR A SHORT TO GROUND
• Measure the resistance between ground and the (T84) EMCC VFS Control circuit.
Is the resistance below 100k Ohms?
Yes
• Repair the (T84) EMCC VFS Control circuit for a short to ground.
• Perform the Transmission Verification Test. Refer to => Non-DTC Based Diagnostics. Transmission Verification Test
No
• Go to Test Step 5
Test Step 5 - CHECK THE (T84) EMCC VFS CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
• Ignition on, engine not running.
• Measure the voltage of the (T84) EMCC VFS Control circuit.
Is the voltage above 0.5 volt?
Yes
• Repair the (T84) EMCC VFS Control circuit for a short to voltage.
• Perform the Transmission Verification Test. Refer to => Non-DTC Based Diagnostics. Transmission Verification Test
No
• Go to Test Step 6
Test Step 6 - CHECK THE (T84) EMCC VFS CONTROL CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
• Turn the ignition off to the lock position.
• Measure the resistance between the (T84) EMCC VFS Control circuit and all other circuits in the Transmission Solenoid/TRS Assembly harness connector.
Is the resistance below 100k Ohms between the (T84) EMCC VFS Control circuit and any other circuit in the Transmission Solenoid/TRS Assembly harness connector?
Yes
• Repair the (T84) EMCC VFS Control circuit for a short to another circuit(s).
• Perform the Transmission Verification Test. Refer to => Non-DTC Based Diagnostics. Transmission Verification Test
No
• Go to Test Step 7
Test Step 7 - CHECK THE EMCC VFS SOLENOID
• Turn the ignition off to the lock position.
• Measure the resistance of the EMCC VFS Solenoid between the (T84) EMCC VFS Control and the (T16) Transmission Control Output on the Transmission Solenoid/TRS Assembly connector.
Is the resistance of the EMCC VFS SOLENOID 5.0 Ohms (± 0.5 Ohms) at 21° C (70° F)?
Yes
• Using the schematics as a guide, check the Transmission Control Module (TCM) pins, terminals, and connectors 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 TCM.
• Perform the Transmission Verification Test. Refer to => Non-DTC Based Diagnostics. Transmission Verification Test
No
• Replace the EMCC VFS Solenoid.
• Perform the Transmission Verification Test. Refer to => Non-DTC Based Diagnostics. Transmission Verification Test
Test Step 8 - 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 the Transmission Verification Test. Refer to => Non-DTC Based Diagnostics. Transmission Verification Test
No
• Test Complete.