P1860

DTC P1860















Circuit Description with 4T65-E Automatic Transaxle
Ignition voltage is provided to the torque converter clutch pulse width modulation (TCC PWM solenoid valve. The PCM controls the ON and OFF time of the solenoid by providing a ground path through the output driver module (ODM). The PCM uses a PWM duty cycle, in order to control application and release of the TCC. When the solenoid is commanded OFF, the PCM senses high volts. When the solenoid is commanded ON, the PCM senses low volts.
If the PCM detects a continuous open, short to ground or short to voltage in the TCC PWM solenoid valve circuit, then DTC P1860 sets. DTC P1860 is a type B DTC.

Conditions for Running the DTC
^ The system voltage is 8 - 18 volts.
^ The engine run time is greater than 5 seconds.
^ The TCC PWM solenoid valve duty cycle is 10 percent or less or 90 percent or greater.

Conditions for Setting the DTC
The TCC PWM solenoid valve feedback circuit indicates a continuous open, short to ground or short to voltage for 4.3 seconds.

Action Taken When the DTC Sets
^ The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
^ The PCM inhibits 4th gear when the transmission is in hot mode.
^ The PCM freezes transmission adapt functions. The PCM records the operating conditions when the Conditions for Setting the DTC are met.
^ The PCM stores this information as Freeze Frame and Failure Records.
^ The PCM stores DTC P1860 in PCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

Conditions for Clearing the MIL/DTC
^ The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.
^ A scan tool can clear the MIL/DTC
^ The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission- related diagnostic fault occurring.
^ The PCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the PCM.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
11. This step tests the PCM and the wiring to the AT inline 20-way connector.
14. This step tests the control circuit for a short to voltage.
16. This step tests the circuit for correct resistance.