What it means
The gear shift lock solenoid/actuator control circuit A reports a control circuit a range/performance condition. Selector lever interlock cannot be commanded reliably.
At a glance
- Usually lights the check-engine light
How it works
Circuit A controls the gear-shift lock actuator that prevents the selector leaving Park until the required release conditions are met. The module monitors the actuator’s commanded response, and sets P0929 when circuit A responds too slowly or outside its expected operating range.
Common causes
Most likely first.
- Actuator response slow
- High-resistance contact
- Sensor element aged beyond calibration window
Symptoms
- Selector may not shift out of Park
- Shift-lock warning or check-engine light may illuminate
How to diagnose it
- Use a scan tool to record freeze-frame data and check whether P0929 returns while the brake is pressed and the selector is operated.
- Check whether the selector releases from Park consistently, since an intermittent or slow release can help confirm the reported performance problem.
- Inspect circuit A’s wiring and connectors at the shift-lock actuator for corrosion, loose terminals, damage, or signs of a high-resistance contact.
- With the scan tool, compare the circuit A command with available actuator or interlock feedback while operating the selector.
- Test circuit A’s wiring and actuator response for excessive resistance or delay, comparing results with the manufacturer's specification.
- If wiring and connections pass, test the circuit A actuator or sensor element for a slow or out-of-calibration response.
Common fixes
- Clean and secure a corroded or loose circuit A connector.
- Repair a damaged or high-resistance connection in circuit A wiring.
- Replace the slow or out-of-calibration circuit A actuator or sensor element.
Can I keep driving?
If the selector releases normally and the vehicle shifts normally, limit driving to necessary trips and arrange diagnosis soon. If it stays locked in Park or cannot be secured in the selected gear, do not force the lever or drive.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.