P0798 - Pressure Control Solenoid C Electrical Malfunction
The P0798 code indicates an electrical fault in the pressure control solenoid C circuit, which is part of the transmission's hydraulic control system. This solenoid regulates line pressure for clutch and band application. The Powertrain Control Module (PCM) detects an open, short, or excessive resistance in the solenoid circuit, often due to wiring issues, connector corrosion, or a failed solenoid. This can lead to harsh shifting, slipping, or transmission overheating.
01. Most Common Causes
- Faulty pressure control solenoid C
- Damaged wiring or connectors in the solenoid circuit
- Low transmission fluid level or dirty fluid
- Internal transmission mechanical failure
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Harsh or erratic shifting
- Transmission slipping or delayed engagement
- 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 solenoid resistance with a multimeter; compare to manufacturer specs.
Step 5: If solenoid is faulty, replace it; if wiring is bad, repair or replace harness.
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 it can cause transmission damage. Limited driving to a repair shop is acceptable if shifting is still smooth.
How much does it cost to fix?▼
Repair costs range from $150 to $400, including parts and labor. Solenoid replacement is typically $100-$250, plus diagnostic fees.