P0964: Pressure Control Solenoid 'C' Control Circuit/Open
The P0964 code indicates that the Powertrain Control Module (PCM) has detected an open or malfunction in the electrical circuit for pressure control solenoid 'C'. This solenoid regulates hydraulic pressure to the transmission clutches and bands for smooth shifting. An open circuit means there is no continuity, often due to a broken wire, damaged connector, or internal solenoid failure. This can cause harsh or erratic shifting, slipping, or transmission overheating.
01. Most Common Causes
- Open or shorted wiring in the solenoid circuit
- Faulty pressure control solenoid 'C'
- Corroded or damaged connector
- Failed PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Harsh or delayed shifts
- Transmission slipping
- Transmission stuck in limp mode or a single gear
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data
Step 2: Visually inspect wiring and connectors for damage or corrosion
Step 3: Test solenoid resistance with a multimeter (typically 4-6 ohms)
Step 4: Check for power and ground at the solenoid connector with the ignition on
Step 5: If wiring and solenoid are good, test PCM output or replace PCM
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. Driving with an open solenoid circuit can cause transmission damage due to improper pressure regulation, leading to slipping or overheating.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, including parts and labor. A solenoid replacement is around $100-$200, plus diagnostic time.