Pressure Control Solenoid Control Circuit Low
The P0966 code indicates that the Powertrain Control Module (PCM) has detected a low voltage or resistance in the control circuit of the pressure control solenoid. This solenoid regulates hydraulic pressure to the transmission clutches and bands for smooth shifting. A low circuit condition can be caused by a faulty solenoid, damaged wiring, poor electrical connections, or a failing PCM. This issue can lead to harsh or erratic shifting, transmission slippage, and potential internal damage if not addressed.
01. Most Common Causes
- Faulty pressure control solenoid
- Damaged or corroded wiring/connectors in the solenoid circuit
- Low transmission fluid level or dirty fluid
- Failed PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Harsh or delayed shifting
- Transmission slipping or overheating
- Reduced fuel economy
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Inspect transmission fluid level and condition; top off or replace if necessary.
Step 3: Visually check wiring and connectors for damage, corrosion, or loose connections.
Step 4: Test the pressure control solenoid resistance with a multimeter (typically 4-6 ohms).
Step 5: If solenoid is out of spec, replace it; if wiring is faulty, repair as needed.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as low transmission pressure can cause internal damage and lead to costly repairs.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, including parts and labor, depending on the cause and vehicle make/model.