P0964
UniversalPressure Control Solenoid B Control Circuit / Open
High SeverityThis code indicates an open circuit within the electrical control system for the transmission pressure control solenoid B. This typically leads to incorrect transmission line pressure, which can cause significant issues with gear shifts and overall transmission performance.
⚠️ Before You Begin (Safety First)
Always ensure the vehicle is safely supported on jack stands if working underneath. Disconnect the battery before performing any electrical diagnostics or repairs to prevent accidental shorts or injury. Allow the engine and transmission to cool down completely before handling transmission fluid or components.
Common Symptoms
- Check Engine Light illuminated
- Harsh or erratic shifting
- Transmission slipping
- Delayed engagement of gears
- Poor fuel economy
- Transmission may enter 'limp mode'
Common Causes
- Open circuit in the wiring to the pressure control solenoid B
- Faulty or damaged pressure control solenoid B
- Corroded or loose electrical connectors
- Internal transmission wiring harness damage
- Less commonly, a faulty Powertrain Control Module (PCM)
Frequently reported on: General/Universal, Various GM models (2000-2015), Various Ford models (2000-2015), Various Chrysler/Dodge models (2000-2015)
Diagnostic Steps
- Visually inspect the wiring harness and connectors for the transmission pressure control solenoid B for any signs of damage, corrosion, or loose connections. Pay close attention to areas where wiring might rub against other components.
- Using a multimeter, test for continuity and resistance in the solenoid's circuit. Check the resistance of the solenoid itself (refer to your vehicle's service manual for specifications). An 'open' reading indicates a problem with the solenoid or wiring.
- If the solenoid resistance is out of specification or shows an open circuit, consider replacing the pressure control solenoid B. This often requires dropping the transmission pan and sometimes the valve body.
- Inspect the transmission fluid level and condition. Low or dirty fluid can sometimes exacerbate transmission issues, though it's not a direct cause of an electrical 'open' circuit.
👨🔧 When to Call a Professional
If you experience severe transmission performance issues, such as harsh shifting, slipping, or a complete loss of gears, it is crucial to stop driving immediately and consult a professional transmission specialist. Continuing to drive can cause irreversible damage to the transmission.
Commonly Asked Questions
What exactly does the 'B' in P0964 refer to?
The 'B' typically refers to a specific pressure control solenoid in the transmission. Most automatic transmissions use multiple solenoids to regulate fluid pressure for different gears and functions.
Can I drive with a P0964 code?
It is not recommended to drive with this code, especially if you are experiencing noticeable transmission problems. Continued driving can lead to further, more expensive damage to the transmission.
Is replacing a transmission solenoid a difficult DIY job?
It can be challenging. It usually requires draining transmission fluid, dropping the transmission pan, and often removing the valve body to access the solenoids. This job is best suited for advanced DIYers or professionals.
What tools will I need to fix P0964?
You'll likely need basic hand tools, a torque wrench, a multimeter for electrical testing, a transmission fluid drain pan, new transmission fluid, and a new transmission pan gasket if you remove the pan.
Could a bad PCM cause P0964?
While less common, a faulty Powertrain Control Module (PCM) could potentially cause this code if its internal circuit for controlling solenoid B is damaged. However, always rule out wiring and the solenoid itself first.