Pressure Control Solenoid C Intermittent
The P0799 code indicates that the Transmission Control Module (TCM) has detected an intermittent fault in the Pressure Control Solenoid C circuit. This solenoid regulates hydraulic pressure for clutch or band application within the automatic transmission. Intermittent issues may stem from wiring, connectors, or the solenoid itself, leading to erratic transmission behavior.
01. Most Common Causes
- Faulty pressure control solenoid C
- Damaged wiring or connectors in the solenoid circuit
- Low transmission fluid level or contaminated fluid
- Internal transmission mechanical issues
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Erratic shifting or harsh gear engagement
- 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 up or replace if necessary.
Step 3: Visually check wiring and connectors for damage, corrosion, or loose connections.
Step 4: Test solenoid resistance and compare to manufacturer specifications.
Step 5: Perform a transmission pressure test to verify solenoid operation.
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 intermittent solenoid failure can cause transmission damage or unsafe driving conditions.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, including parts and labor, depending on the root cause and vehicle model.