P0748 - Pressure Control Solenoid A Electrical
The P0748 code indicates an electrical malfunction in the pressure control solenoid 'A' circuit, which is part of the transmission's hydraulic control system. This solenoid regulates line pressure to control shift feel and timing. 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 faulty solenoid. This can lead to harsh shifting, slipping, or transmission overheating.
01. Most Common Causes
- Faulty pressure control solenoid A
- Open or shorted wiring in solenoid circuit
- Corroded or damaged connector
- 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
- Poor fuel economy
- Transmission overheating
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 (typically 4-6 ohms); compare to specs.
Step 5: Check for power and ground at solenoid connector with key on; 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 it can cause transmission damage. Short trips to a repair shop may be acceptable if shifting is still smooth.
How much does it cost to fix?▼
Diagnosis typically costs $50-$150. Solenoid replacement can range from $150-$400 for parts and labor, but if internal transmission damage is found, costs can exceed $1,500.