P1860

Diagnostic Chart:

Wiring Diagram:

Circuit Description

The Torque Converter Clutch Pulse Width Modulation Solenoid Valve (TCC PWM Sol. Valve) controls the fluid pressure to the converter clutch regulator valve, thereby controlling converter clutch apply pressure. A fused circuit provides ignition voltage to the solenoid. An Output Driver Module (ODM), in the PCM, provides the ground to energize the solenoid. The solenoid valve is modulated by the PCM, varying the duty cycle. At 0% duty cycle the torque converter clutch applies at maximum capacity. At 100% duty cycle the torque converter clutch applies at minimum capacity.

When the PCM detects a continuous open, or short to ground in the TCC PWM Sol. circuit, then DTC P1860 sets. DTC P1860 is a type A DTC.

Conditions for Setting the DTC

^ System voltage is 10-16 volts.

^ The engine speed is more than 500 RPM for 5 seconds.

^ Not in fuel shut off.

^ The PCM commands the solenoid below 10%, and above 90% duty cycle, and the voltage on circuit 418 is outside the calibrated limits.

Action Taken When the DTC Sets

^ The PCM illuminates the Malfunction Indicator Lamp (MIL).

^ The PCM inhibits TCC operation.

^ The PCM inhibits 4th gear if the transmission is in the hot mode.

Conditions for Clearing the MIL/DTC

^ The PCM turns OFF the MIL after three consecutive trips without a failure reported.

^ A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported.

^ The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM.

Diagnostic Aids

^ Inspect the wiring at the PCM, the transmission connector, TCC PWM solenoid connector and all other circuit connecting points for the
following conditions:

- A bent terminal.

- A backed out terminal.

- A damaged terminal.

- Poor terminal tension.

- A chafed wire.

- A broken wire inside the insulation.

- Moisture intrusion.

- Corrosion

^ When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the test equipment for a change.

^ Ensure that the transmission fluid is at the proper level.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

3. This step isolates the engine harness from the transmission harness.

5. This step verities that circuit 418 is not open or shorted to power.

8. This step verities that the solenoid is not open or shorted across its windings, and the transmission harness is not open or shorted.