With Powertrain Control Module
Wiring Diagram:
CIRCUIT DESCRIPTION
The Torque Converter Clutch Pulse Width Modulation Solenoid Valve (TCC PWM Sol. Valve) controls fluid acting on the converter clutch valve, which then controls TCC apply and release. The TCC PWM Sol. Valve attaches to the control valve body within the transmission. Ignition voltage goes directly to the TCC PWM Sol. Valve. The Powertrain Control Module (PCM) controls the TCC PWM Sol. Valve by providing a ground path on circuit 418. The current flows through the TCC PWM Sol. Valve coil according to the duty cycle (percentage of ON and OFF time). The TCC PWM Sol. Valve provides a smooth engagement of the torque converter clutch by operating on a duty cycle percent of ON time. If the PCM detects a continuous open or short to ground in the TCC PWM Sol. Valve circuit or the TCC PWM Sol. Valve, then DTC P1860 sets. DTC P1860 is a type A DTC.
CONDITIONS FOR SETTING THE DTC
^ System voltage is 9.0-16.0 volts.
^ The engine is running more than 475 RPM for greater than 7 seconds.
^ Commanded gear is 1st.
^ All of the above conditions are met, and either of the following conditions occur for 4.3 seconds out of 5 seconds.
- The PCM commands the solenoid OFF, and the voltage input remains low (zero volts).
- The PCM commands the solenoid to ON (100%) and the voltage input remains high (B+).
ACTION TAKEN WHEN THE DTC SETS
^ The PCM illuminates the Malfunction Indicator Lamp (MIL).
^ The PCM inhibits TCC engagement.
^ The PCM inhibits 4th gear.
^ DTC P1860 is stored in PCM history.
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 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, massage the wiring harness while watching the test equipment for a change.
^ An open in the ignition feed circuit 1020, will cause multiple DTCs to set.
^ First diagnose and clear any engine DTCs that are present. Then inspect for any transmission DTCs that may have reset.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
4. This step tests for voltage to the TCC PWM Sol. Valve.
6. This step tests the ability of the PCM and wiring to control the TCC PWM Sol. valve ground circuit.
8. This step tests the resistance of the TCC PWM Sol. Valve and the Automatic Transmission Wiring Harness Assembly.
12. If the Automatic Transmission Wiring Harness Assembly is open, do not repair the wiring harness. You must replace the Automatic Transmission Wiring Harness Assembly.