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2019 GMC ACADIA

2.5L I4AWDAUTOMATICgas
2 active safety recalls on this vehicle — view recalls
Repairs0Labor515Torque5041Fluid9DTC971Battery0Maintenance0Recalls2
P1860moderate severityPowertrain

TCC PWM Solenoid Circuit Electrical

on 2019 GMC Acadia 2.5L I4 · AWD

What this code means

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.

Other Powertrain codes on this vehicle

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