Vehicle Shifted to Park -- Driver Seat Vacated While Not in Park (Informational)
The TESLA-DI_A166 (Tesla Drive Inverter (DI)) EV fault code means: Vehicle Shifted to Park -- Driver Seat Vacated While Not in Park (Informational). This is a low severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- beginner
- Estimated cost
- $0 -- this is normal behavior; only a misreading seat-occupancy or seatbelt sensor (rare) would need service.
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Common Symptoms
- Car automatically shifts into Park
- On-screen note that the vehicle was put in Park because the driver seat was vacated
- Happens when you get out (or lean out) while the car is not already in Park
- No persistent warning light once you are back in the seat and shift normally
Probable Causes (Ranked by Likelihood)
- Normal safety behavior: the car detected the driver seat was empty (seat sensor + seatbelt) while not in Park and shifted to Park to prevent rollaway Very Likely
- Getting out briefly, or a light/loosely-seated occupant being read as "driver left" by the seat sensor Possible
Step-by-Step Diagnostic Procedure
This is an informational/safety alert, not a fault -- the car shifts to Park when it thinks the driver has left while not in Park. No repair is needed in normal use.
If it triggers while you are genuinely seated and driving, the driver seat-occupancy sensor or seatbelt sensor may be misreading -- have it checked by Tesla service.
Simply sit down, buckle, and shift normally to resume.
Frequently Asked Questions
Is DI_a166 a problem?
No, in normal use it is an informational safety message: the car shifted itself into Park because it detected the driver seat was vacated while the car was not already in Park. It prevents rollaway. No repair is needed.
Why did my Tesla shift to Park by itself?
If you opened the door or got partway out while in Drive or Neutral, the car puts itself in Park as a safety measure (DI_a166). Get back in, buckle up, and shift normally. If it happens while you are clearly seated, have the seat/seatbelt sensor checked.
Sources
This page is built from documented references. Verify against your own service info before repair work.