P1860

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

Ignition voltage is provided to the Torque Converter Clutch Pulse Width Modulation Solenoid Valve (TCC PWM Sol. Valve). The Powertrain Control Module (PCM) controls the ON and OFF time of the solenoid by providing a ground through the Output Driver Module (ODM) B. The PCM uses a Pulse Width Modulated (PMW) duty cycle, in order to control application and release of the Torque Converter Clutch (TCC). When the solenoid is commanded OFF, the PCM senses high volts. When the solenoid is commanded ON, the PCM senses low volts.

DTC P1860 sets anytime the received voltage is outside of the calibration limits. DTC P1860 is a type A DTC.

CONDITIONS FOR SETTING THE DTC

^ The system voltage is 9 - 16 volts.

^ The engine speed is greater than 500 RPM for 5 seconds, and not in fuel shut off.

^ The ignition is ON.

^ The PCM commands the solenoid to greater than 90% duty cycle and voltage remains low (0.0 volts).

^ The PCM commands the solenoid to less than 10% duty cycle and voltage remains high (B+).

^ All conditions are met for 5 seconds.

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

^ The PCM disables shift adapts.

CONDITIONS FOR CLEARING THE MIL/DTC

^ The PCM turns OFF the Malfunction Indicator Lamp (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 for poor electrical connections at the PCM. Inspect the wiring at the transmission 20-way connector. Inspect the wiring at the 2-way TCC connector. Look for the following problems:

- A bent terminal

- A backed out terminal

- A damaged terminal

- Poor terminal tension

- A chafed wire

- A broken wire inside the insulation

^ When diagnosing for an intermittent short or open, 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.

6. This step isolates the engine harness from the transmission harness. Use a test lamp in order to verify the circuitry.

8. This step verifies that circuit 418 is not open or shorted to power.

12. This step verifies that the TCC PWM solenoid is not shorted across its windings or increased its resistance.

19. Because of the harsh conditions inside the transmission, repairing the A/T Wiring Harness is not acceptable. You must replace the A/T Wiring Harness.