Shift Solenoid Control Circuit Low
The P099E code indicates that the Powertrain Control Module (PCM) has detected a low voltage condition in the control circuit of a specific shift solenoid. This solenoid is responsible for regulating hydraulic pressure to engage the correct gear. A low voltage reading suggests a short to ground, open circuit, or faulty solenoid, which can cause erratic shifting, transmission slippage, or failure to shift.
01. Most Common Causes
- Faulty shift solenoid
- 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 delayed shifting
- Transmission stuck in a single gear
- Decreased fuel economy
03. Step-by-Step Diagnosis
Step 1: Scan for additional 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 the shift solenoid resistance with a multimeter; compare to manufacturer specs.
Step 5: If solenoid is faulty, replace it; if wiring is damaged, repair or replace as needed.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. Driving with a low voltage solenoid circuit can cause unpredictable shifting, potential transmission damage, or complete failure. Have it diagnosed and repaired promptly.
How much does it cost to fix?▼
The cost typically ranges from $150 to $400, including parts and labor. Replacing a shift solenoid is often $50-$150 for the part and $100-$250 for labor, depending on vehicle accessibility.