P1860

Circuit Description
The PCM allows current to flow through the solenoid coil. This current flow through the solenoid coil creates a magnetic field that magnetizes the solid core. The magnetized core attracts the check ball to seat against spring pressure. This blocks the exhaust for the TCC signal fluid and allows 2-3 drive fluid to feed to TCC signal circuit. The TCC signal fluid pressure acts on the TCC regulator valve to regulate line pressure and to apply fluid pressure to the torque converter clutch shift valve. When the TCC shift valve is in the apply position, regulated apply fluid pressure is directed through the TCC valve to apply the torque converter clutch. The TCC solenoid is used in conjunction with the TCC solenoid to regulate fluid to the torque converter. The TCC solenoid is attached to the valve body within the transmission.
This DTC detects a continuous open or short to ground or ignition in the TCC circuit or the TCC solenoid. This is a type "B" DTC.

Conditions For Setting The DTC
- Battery voltage is between 10 and 16 volts.
- No shift solenoid A DTCs P0751 or P0753.
- No shift solenoid B DTCs P0756 or P0758.
- Ignition "on". Engine "run"
- The PCM commands the solenoid "on" and the voltage remains low (zero volts).
- The PCM commands the solenoid "off" and the voltage remains high (B+).
- All conditions met for 0.25 seconds.

Action Taken When The DTC Sets
- Inhibit TCC engagement.
- The PCM will illuminate the Malfunction Indicator Lamp (MIL) and CHECK TRANS Lamp.

Conditions For Clearing The MIL/DTC
- The PCM will turn off the MIL and CHECK TRANS Lamp after three consecutive ignition cycles without a failure reported.
- The DTC can be cleared from the PCM history by using a scan tool.
- The DTC will be cleared from history when the vehicle has achieved 40 warmup cycles without a failure reported.
- The PCM will cancel the DTC default actions when the fault no longer exists and the ignition is cycled "off,' long enough to power down the PCM.

Diagnostic Aids
- Inspect the wiring for poor electrical connections at the PCM and at the transmission 16-way connector. Look for possible bent, backed out, deformed or damaged terminals. Check for weak terminal tension as well. Also check for a chafed wire that could short to bare metal or other wiring. Inspect for a broken wire inside the insulation.
- When diagnosing for a possible intermittent short or open condition, move the wiring harness while observing test equipment for a change.

Test Description
The numbers below refer to the step numbers on the diagnostic chart:
3. This test checks for voltage to the solenoid.
4. This test checks the ability of the PCM and wiring to control the ignition circuit.
9. This test checks the resistance of the TCC solenoid and the internal wiring harness.








DTC P1860 TCC Solenoid Electrical