P1860

P1860 - TCC PWM SOLENOID CIRCUIT (L81)










The Torque Converter Clutch (TCC) solenoid contains a normally closed valve used to control the apply and release of the converter clutch. The TCM operates the solenoid with a duty cycle. When vehicle operating conditions are appropriate to apply the TCC, the TCM immediately increases the duty cycle to approximately 42%. The TCM then ramps the duty cycle to approximately 90% to achieve full TCC apply pressure. When the solenoid is commanded OFF, the TCM feedback is high. When the solenoid is commanded ON, the TCM feedback is low. When the TCM detects a continuous open, short to ground or short to power in the TCC solenoid circuit, then DTC P1860 sets.

DTC PARAMETERS
DTC P1860 will set if the TCM detects an open or short to ground on the TCC solenoid control circuit when:
^ TCM is commanding a 10% or less TCC duty cycle
^ Engine run time is greater than 5 seconds
^ Ignition voltage is between 8 and 18 volts
OR
DTC P1860 will set if the TCM detects a short to voltage on the TCC solenoid control circuit when:
^ TCM is commanding a 90% or greater TCC duty cycle
^ Engine run time is greater than 5 seconds
^ Ignition voltage is between 8 and 18 volts

DIAGNOSTIC AIDS
Inspect the wiring at TCM, transaxle connector, and TCC solenoid connector 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
^ Ensure transaxle fluid is at proper level.
^ When diagnosing for an intermittent short or open condition, massage the wiring harness while watching test equipment for a change.