Shift Timing Solenoid A Range/Performance
The P0786 code indicates that the Powertrain Control Module (PCM) has detected a malfunction in the shift timing solenoid 'A' circuit. This solenoid controls hydraulic pressure to engage specific gears in the automatic transmission. The 'range/performance' aspect means the solenoid is not operating within its expected parameters, often due to electrical issues, mechanical sticking, or transmission fluid problems.
1. Symptoms You Will Notice
- Check Engine Light illuminated
- Harsh or erratic shifting
- Transmission slipping or stuck in gear
- Decreased fuel economy
2. Most Common Causes
- Faulty shift timing solenoid A
- Low or dirty transmission fluid
- Wiring or connector issues in the solenoid circuit
- Internal transmission mechanical failure
3. Step-by-Step Diagnosis
Step 1: Scan for codes and verify P0786 is present. Check for additional transmission codes.
Step 2: Inspect transmission fluid level and condition. Low or burnt fluid indicates a problem.
Step 3: Test solenoid A resistance and power/ground circuits using a multimeter. Compare to manufacturer specs.
Step 4: If electrical tests pass, remove the transmission pan and inspect solenoid for debris or sticking. Replace if faulty.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. Driving with P0786 can cause erratic shifting, transmission damage, or complete failure. Have it diagnosed promptly.
How much does it cost to fix?▼
Repair costs range from $150 to $400, depending on whether the solenoid alone needs replacement or if additional transmission work is required.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.