P2720: Pressure Control Solenoid 'C' Control Circuit Low
The P2720 code indicates that the Powertrain Control Module (PCM) has detected a low voltage condition in the control circuit of the pressure control solenoid 'C'. This solenoid is part of the transmission's hydraulic system, regulating fluid pressure for clutch and band application. A low circuit condition typically results from wiring issues, a faulty solenoid, or a PCM problem, leading to improper transmission operation.
1. Most Common Causes
- Short to ground in the signal wire of pressure control solenoid 'D'
- Open circuit in the voltage supply (B+) or ground circuit of the solenoid
- High resistance or loose/corroded connector in the solenoid harness
- Faulty pressure control solenoid 'D' (internal coil short)
- Damaged output driver in the transmission control module (TCM/PCM)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Harsh or erratic shifting
- Transmission slipping or stuck in gear
- Reduced fuel economy
3. Step-by-Step Diagnosis
Step 1: Scan for additional codes and freeze frame data.
Step 2: Visually inspect wiring and connectors for damage, corrosion, or loose connections.
Step 3: Test solenoid resistance with a multimeter (typically 5-20 ohms).
Step 4: Check for voltage and ground at the solenoid connector with the ignition on.
Step 5: If wiring and solenoid are good, test PCM output or replace PCM.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as the transmission may shift erratically or fail, potentially causing further damage.
How much does it cost to fix?▼
Repair costs range from $150 to $400, including parts and labor, depending on whether the solenoid or wiring needs replacement.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.