Shift Solenoid Control Circuit Range/Performance
The P099A code indicates that the powertrain control module (PCM) has detected a performance or range issue in the control circuit of a specific shift solenoid. This solenoid is responsible for directing transmission fluid to engage the correct gear. The problem may stem from electrical faults (e.g., open or short circuit), mechanical sticking of the solenoid, or low transmission fluid pressure. This can lead to erratic shifting, transmission slippage, or failure to shift.
01. Most Common Causes
- Faulty shift solenoid
- Wiring or connector damage in the solenoid circuit
- Low or contaminated transmission fluid
- Internal transmission mechanical failure
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Harsh or delayed shifting
- Transmission stuck in a single gear (limp mode)
- Decreased 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.
Step 3: Visually check wiring and connectors for damage or corrosion.
Step 4: Test solenoid resistance and power/ground circuits with a multimeter.
Step 5: Perform a solenoid actuation test using a scan tool.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. Driving with this code can cause further transmission damage and unsafe driving conditions due to erratic shifting.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, depending on whether the solenoid alone needs replacement or if additional wiring repairs are needed.