Shift Solenoid A Malfunction (P0750)
The P0750 code indicates a malfunction in the shift solenoid 'A' circuit, which controls hydraulic pressure to engage specific gears in the automatic transmission. This solenoid is typically located inside the transmission valve body and is responsible for shifting between 1st and 2nd gears. The Powertrain Control Module (PCM) monitors the solenoid's electrical circuit and detects an open, short, or excessive resistance. Common causes include faulty solenoid, dirty transmission fluid, wiring issues, or a defective PCM.
1. Symptoms You Will Notice
- Check Engine Light illuminated
- Transmission stuck in limp mode (usually 2nd gear)
- Harsh or delayed shifting
- Poor fuel economy
- Transmission slipping or overheating
2. Most Common Causes
- Faulty shift solenoid 'A' (open or shorted coil internally)
- Open, short-to-ground, or short-to-voltage in the solenoid control circuit wiring
- Corroded, loose, or damaged connector terminals at the solenoid or TCM/PCM
- Defective transmission control module (TCM/PCM)
- Low transmission fluid level, contaminated fluid, or valve body blockage preventing solenoid mechanical movement
3. Step-by-Step Diagnosis
Step 1: Scan for codes and verify P0750 is present. Check freeze frame data for conditions.
Step 2: Inspect transmission fluid level and condition. Low or burnt fluid indicates a problem.
Step 3: Visually check wiring and connectors to the solenoid for damage, corrosion, or loose pins.
Step 4: Use a multimeter to test solenoid resistance (typically 20-30 ohms). Compare to specs.
Step 5: If solenoid and wiring are okay, perform a transmission pressure test to rule out mechanical issues.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. The transmission may go into limp mode, limiting speed and causing harsh shifts. Continued driving can lead to internal damage.
How much does it cost to fix?▼
Repair costs range from $150 to $400 for solenoid replacement, including parts and labor. If transmission fluid change or internal repairs are needed, costs can exceed $1,000.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.