ShopBaseFree forever shop management software for auto repair shops
Try ShopBase Free β†’
P1860

TCC PWM Solenoid Circuit Electrical

2002-2007 Buick Rendezvous 3.5L V6

Moderate SeverityPowertrain

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

  1. Test TCC PWM solenoid resistance (should be 10-16 ohms)
  2. Check for open, short to ground, or short to power on solenoid circuit
  3. Inspect transmission connector for damage
  4. Clear codes and road test
  5. 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

P0740Torque Converter Clutch Circuit MalfunctionP0741Torque Converter Clutch Circuit Performance/Stuck OffP0742Torque Converter Clutch Circuit Stuck OnP1870Transmission Component SlippingP1870Transmission Component SlippingP1870Transmission Component SlippingP1870Transmission Component SlippingP1870Transmission Component SlippingP1870Transmission Component SlippingP1870Transmission Component SlippingP1870Transmission Component Slipping

Other Powertrain Codes

P1860 on Other Vehicles

Common Questions

What does code P1860 mean on a 2002-2007 Buick Rendezvous?

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 Buick Rendezvous?

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 2002-2007 Buick Rendezvous?

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.

View Labor Times | View Torque Specs | View Fluid Specs