Front Drive Unit Disabled (Dual-Motor Vehicle Running on Rear Motor)
The TESLA-DI_A138 (Tesla Drive Inverter (DI)) EV fault code means: Front Drive Unit Disabled (Dual-Motor Vehicle Running on Rear Motor). This is a serious severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- expert
- Estimated cost
- Depends on the root cause; a drive-unit or inverter fault is diagnosed and quoted by Tesla service. Diagnose the underlying alert before estimating.
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Common Symptoms
- Reduced power and acceleration
- Loss of all-wheel drive on a dual-motor vehicle (rear-drive only)
- A "vehicle needs service" or reduced-power message
- Often accompanied by other drive-inverter alerts that identify the root fault
Probable Causes (Ranked by Likelihood)
- A fault in the front drive unit or front inverter caused the controller to disable the front motor Likely
- A thermal, electrical, or internal drive-inverter condition triggering protective shutdown of the front unit Possible
Frequently Asked Questions
What does DI_a138 mean on a Tesla?
The front drive unit has been disabled. On a dual-motor (AWD) Tesla the car keeps running on the rear motor, but with reduced power and no all-wheel drive. It is triggered by an underlying front-inverter fault.
Can I drive with the front drive unit disabled?
A dual-motor car will still move on the rear motor, so you can drive a short distance, but with reduced power and no AWD traction. Have it diagnosed by Tesla service rather than continuing to drive on it.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
On a dual-motor car the rear motor keeps the vehicle moving, but you lose AWD traction and full power, so drive cautiously, especially in low-grip conditions.
DI_a138 indicates the front unit was disabled in response to another fault -- read the full alert list to find the root front-drive-inverter cause.
High-voltage drive-unit diagnosis is a Tesla service task.
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- Tesla firmware alert reference (core-hacked/tesla-alerts-dictionary): DI_a138_frontUnitDisabledcommunity-maintained dictionary, not an official manufacturer document
- Tessie Tesla alert statisticsthird-party Tesla alert reference with owner-telemetry frequency — not an official Tesla document
Commonly Affected Vehicles
- Tesla Model 3
- Tesla Model Y
- Tesla Model S
- Tesla Model X
- Tesla Cybertruck
Related Codes
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