TCC PWM Solenoid Circuit Electrical
2002-2009 GMC Envoy 4.2L I6 🇩🇪
Description
The PCM/TCM detected a continuous open, short to ground, or short to power in the Torque Converter Clutch (TCC) Pulse Width Modulation (PWM) solenoid valve circuit. The TCC PWM solenoid controls smooth engagement of the torque converter clutch by varying duty cycle. Normal solenoid resistance is 10-16 ohms.
Symptoms
- Check Engine Light
- Transmission slipping
- Harsh shifting
- No torque converter lockup
- Reduced fuel economy
- Bucking feeling at highway speed
- Transmission overheating
Common Causes
- Failed TCC/PWM solenoid (most common)
- Broken or corroded wiring to solenoid
- Short in wire harness
- Faulty PCM/TCM
- Poor electrical connection at transmission connector
- PCM software needing update
Diagnostic Steps
- Test TCC PWM solenoid resistance (should be 10-16 ohms)
- Check for open, short to ground, or short to power on solenoid circuit
- Inspect transmission connector for damage
- Clear codes and road test
- Test PCM solenoid driver output
Repair Notes
Check solenoid resistance first. Replace TCC PWM solenoid if out of spec. Inspect transmission connector and wiring. Solenoid is accessible by removing transmission pan and valve body.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
P1860 on Other Vehicles
Common Questions
What does code P1860 mean on a 2002-2009 GMC Envoy?
P1860 stands for "TCC PWM Solenoid Circuit Electrical". The PCM/TCM detected a continuous open, short to ground, or short to power in the Torque Converter Clutch (TCC) Pulse Width Modulation (PWM) solenoid valve circuit. The TCC PWM solenoid controls smooth engagement of the torque converter clutch by varying duty cycle. Normal solenoid resistance is 10-16 ohms.
What are the symptoms of P1860 on a GMC Envoy?
Common symptoms of P1860 include: Check Engine Light, Transmission slipping, Harsh shifting, No torque converter lockup, Reduced fuel economy, Bucking feeling at highway speed, Transmission overheating.
What causes P1860 on a 2002-2009 GMC Envoy?
Common causes of P1860 include: Failed TCC/PWM solenoid (most common), Broken or corroded wiring to solenoid, Short in wire harness, Faulty PCM/TCM, Poor electrical connection at transmission connector, PCM software needing update.