The Torque Converter Clutch (TCC) solenoid is located in the transmission adapter case. The solenoid valve controls the engagement and disengagement of the torque converter clutch in 3rd and 4th gears. The TCC operation is dependent on transmission fluid temperature, brake switch state, selected program, vehicle speed, etc. The TCM controls the TCC solenoid and the solenoid controls transmission fluid flow to the TCC.
The TCC solenoid is supplied power via the Transmission Power Relay (internal to the TCM). The TCM controls the solenoid by grounding the control circuit via an internal solid state device called a driver. The primary function of the driver is to supply the ground for the controlled component. Each driver has a fault line which is monitored by the TCM. When the TCM is commanding a component on, the voltage of the control circuit should be low (near 0 volts). When the TCM is commanding the control circuit to a component off, the voltage potential of the circuit should be high (near the battery voltage). If the fault detection circuit senses a voltage other than what you expect, this DTC will set.
Tests continuously
A short to ground, open circuit, or short to battery voltage detected on the control circuit.
• | The TCM illuminates the Service Transmission Lamp (STL) and sends a MIL Request to the ECM on the second consecutive drive trip that the diagnostic runs and fails. The ECM then illuminates the MIL. |
• | The ECM records the operating conditions in the Freeze Frame at the time of the MIL Request from the TCM. |
• | The transmission operates in the Default Mode. |
• | The TCM turns off the STL as soon as the fault is no longer present. |
• | The ECM turns off the MIL after three consecutive drive trips during which the TCM sends no MIL Request. |
• | A History DTC clears after forty consecutive warm-up cycles, if no failures are present by this diagnostic or any other emission related diagnostic. |
• | The scan tool clears the MIL/DTC. |
Use the Connector Test Adapter Kit J 35616-A for any test that requires probing the TCM harness connector or a component harness connector. Using this kit will prevent damage to the harness connector terminals.
Check for the following conditions:
• | Poor connections at the TCM or at the component. Inspect the harness connectors for any backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. Refer to Engine Electrical, Troubleshooting Procedures, Checking Terminal Contact for proper procedure. |
• | Damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, observe the scan tool while moving any related connectors and any wiring harnesses. A change in the display may help to locate the fault. |
The number(s) below refer to the step numbers on the diagnostic table.
Lets the TCM determine if the fault is present now.
Listen for an audible click when the solenoid operates. Ground the circuit repeatedly if necessary.
This check can detect a partially shorted coil which would cause an excessive current flow. Leaving the circuit energized for 2 minutes allows the coil to warm up. When the coil warms up, the coil may open (Amps drop to 0), or short (goes above 0.75 Amp).
Be sure to probe the correct Transmission Power Relay output circuit (there are two in the adapter case harness). Pins 54 and 40 are connected within the TCM.
If the solenoid checks out OK and no trouble is found with the connections at the TCM, check the wiring and connections closely. If no trouble is found, the TCM may be the cause of the problem; however this would be an extremely unlikely failure.
Step
| Action | Value(s) | Yes | No | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||||||||||
Is DTC P0743 set? | -- | No trouble found Refer to Diagnostic Aids | ||||||||||
Does the solenoid operate? | -- | |||||||||||
Measure current from the solenoid control circuit in the TCM harness connector to ground for 2 minutes with a DVM J 39200 on a 10 Amp scale. Does the current draw a measure within the range shown? | 0.4 to 0.75A | |||||||||||
Does the test light illuminate? | -- | |||||||||||
6 | With the test light connected to ground, probe the solenoid control circuit in the harness connector. Does the test light illuminate? | -- | ||||||||||
7 | Connect the test light between the Transmission Power Relay output circuit and the solenoid control circuit at the transmission adapter case harness connector. Does the test light illuminate? | -- | ||||||||||
8 | With the test light still connected, jumper the solenoid control circuit to ground at the TCM harness connector. Does the test light illuminate? | -- | ||||||||||
9 | Check the transmission harness connector for a poor connection or poor terminal tension. Refer to Engine Electrical, Troubleshooting Procedures, Checking Terminal Contact for proper procedure. Was a problem found and corrected? | -- | ||||||||||
10 | Repair the solenoid control circuit shorted to B+. Is the action complete? | -- | -- | |||||||||
11 | Repair the solenoid control circuit shorted to ground. Is the action complete? | -- | -- | |||||||||
12 | Repair the open/high resistance solenoid control circuit. Is the action complete? | -- | -- | |||||||||
13 | Repair the Transmission Power Relay output circuit to the solenoid. Is the action complete? | -- | -- | |||||||||
14 | Check the internal transmission harness to the solenoid for the following conditions:
Was a problem found and corrected? | -- | ||||||||||
15 | Replace the solenoid. Is the action complete? | -- | -- | |||||||||
Check the TCM harness connector for a poor connection or poor terminal tension. Refer to Engine Electrical, Troubleshooting Procedures, Checking Terminal Contact for proper procedure. Was a problem found and corrected? | -- | Go to Test Description | ||||||||||
17 |
Is DTC P0743 set? | -- | ||||||||||
18 | Were there any additional DTCs noted during the Powertrain or Transmission OBD System Check that have not been diagnosed? | -- | Go to the applicable DTC table | |||||||||
19 | Does the Transmission now function properly? | -- | System OK | Go to Functional Test |