DI_a115: Drive Inverter Fault
DI_a115 is a manufacturer-specific diagnostic trouble code in the the manufacturer's own system grouping group. Our vehicle database stores it against 2 models.
How serious is DI_a115?
We rate DI_a115 as High — address promptly, the top of our three-level scale. That rating comes from the severity recorded in our database for this code, not from how alarming the name sounds.
A high-severity code means the fault can damage expensive components if it is ignored. Continuing to drive is a judgement call that depends on how the vehicle behaves: if it is misfiring badly, losing power, overheating, or flashing the check-engine light, stop driving and have it recovered. A flashing check-engine light specifically indicates an active misfire that can destroy a catalytic converter within a short distance.
What DI_a115 actually means
DI_a115 is not on the shared SAE J2012 list: it is a manufacturer-specific code, so its definition comes from the maker’s own service documentation rather than the standard numbering scheme. Our vehicle database stores it against 2 models.
The stored definition for DI_a115 is “Drive Inverter Fault”. The first character of the code identifies the system — manufacturer-specific in this case. The second character tells you who defined the code: this one is a manufacturer-specific code. Reading the code that way matters: a manufacturer-defined code means the test and its causes are the maker’s own, so the list below is narrower by design and generic code references will not define it.
Within that system, DI_a115 sits in the the manufacturer's own system grouping group. That is the part of the vehicle the control module was watching when it set the code — the subsystem this code belongs to — and it narrows down enormously where a technician will start looking. Manufacturer-specific codes are worked with the maker’s own service procedure, so the factory test routine matters more than generic advice.
Most likely causes of DI_a115, ranked
Our database records 3 causes for DI_a115, ranked by how many of the 2 models that log this code report each one.
- front drive unit inverter failure — logged by a single model in our database.
- Rear — logged by a single model in our database.
- Rear drive unit inverter MOSFET failure — logged by a single model in our database.
Causes are listed as recorded in the database. The same code can have different root causes on different vehicles, so the ranking is a starting order for diagnosis rather than a diagnosis in itself.
How a technician diagnoses DI_a115
Manufacturer codes are worked with the maker’s own service procedure, so the factory test routine matters more than generic advice. Confirm the code is active rather than historic, then work through the ranked causes from cheapest and most likely to most intrusive. In practice that means:
How a technician works DI_a115 — decision path
This is a code the manufacturer defined rather than one from the SAE J2012 scheme, so the factory procedure matters more than generic advice. Expect to need the maker's own scan tool.
- Read the code with the manufacturer's scan toolGeneric OBD-II readers often cannot display manufacturer codes or their sub-status, and the sub-status is usually what distinguishes "current" from "stored".
- Run the factory diagnostic routineManufacturer codes generally have a guided test in the service software that isolates the subsystem in a few steps — follow it rather than improvising.
- Check for related bulletins and open campaignsManufacturer-specific codes are frequently covered by a technical service bulletin or a recall, and the fix may be a software update or a covered repair rather than a part you pay for.
- Verify with the factory tool after the repairConfirm the code is cleared and the associated monitor or calibration routine has completed, since these codes often require a specific drive or activation pattern to re-test.
If a workshop replaces a component for DI_a115 without showing you the measurement that condemned it, ask for the data. On a the manufacturer's own system grouping code, the recorded causes are usually testable, so a diagnosis should be demonstrable rather than asserted.
What drives the cost of fixing DI_a115
We deliberately do not print a single repair price for DI_a115. The parts bill depends entirely on which recorded cause is confirmed. The honest answer is that the cost is set by which cause is actually present, and that range is wide — a repair for the first cause listed above and the last can differ by more than an order of magnitude in parts alone: the confirmed cause moves the bill more than any other variable. Add regional labour rates and the spread becomes wider still.
The factors that actually move the number, in rough order of impact:
- Sensor or module. Whether the confirmed cause is a sensor or a control module is the first thing that moves the bill, and on manufacturer-specific systems the pricing is the maker’s own.
- Access. Access varies more on manufacturer-defined systems than on standard ones, because the component placement is not shared across models.
- Dealer-network parts. Some manufacturer-specific components are only available through the dealer network, which removes the aftermarket option from the comparison.
- Diagnosis billed separately. Manufacturer codes are worked with the maker’s own procedure, so the diagnostic step takes the time it takes.
The practical approach: get the cause confirmed first, then collect two or three written quotes for that specific repair. To judge whether the repair is worth doing against the value of the vehicle, use our repair-or-replace decision guide.
Vehicles in our database that log DI_a115
Only 2 models in our database record DI_a115, so the list below is short but specific. The makes appearing most often are Tesla (2). Each model links to its own guide, where this code appears alongside that vehicle's full fault list and running costs.
Frequently asked questions about DI_a115
Is DI_a115 a generic OBD-II code?
No. DI_a115 is a manufacturer-specific code, so it does not appear on the shared SAE J2012 list and generic code references will not define it. Its meaning comes from the manufacturer’s own service documentation, which is also why the causes listed on this page are narrower than for a generic code.
Is it safe to drive with DI_a115?
Severity for DI_a115 is rated high in our database. A high-severity code means the fault can damage expensive components if it is ignored. Continuing to drive is a judgement call that depends on how the vehicle behaves: if it is misfiring badly, losing power, overheating, or flashing the check-engine light, stop driving and have it recovered. A flashing check-engine light specifically indicates an active misfire that can destroy a catalytic converter within a short distance.
What are the most common causes of DI_a115?
In our vehicle database, the causes recorded for DI_a115 are: front drive unit inverter failure; Rear; Rear drive unit inverter MOSFET failure. They are ranked on the page by how many of the 2 vehicles that log this code list each cause.
How much does it cost to fix DI_a115?
We do not publish a single figure for DI_a115 because the real cost depends entirely on which cause is present — a repair for the cheapest cause on the list and the most expensive one differ by an order of magnitude, and labour rates vary by region. The page explains which factors drive the cost and recommends collecting written quotes before authorising work.
Which vehicles commonly report DI_a115?
Our database stores DI_a115 against 2 vehicles, most frequently from Tesla (2). The full list is shown on this page and each model links to its own cost and fault guide.
Related codes and next steps
Codes that share the same system group often appear together, because a single fault can set more than one:
For the full list, see the OBD-II fault code cross-reference. If the repair cost is what you are weighing, model the total with our total cost of ownership calculator before deciding, and check whether an open safety recall covers the fault with the recall lookup.
Sources and scope
Code definitions follow SAE J2012 / ISO 15031-6 naming. The descriptions, listed causes, and severity ratings on this page are the values stored in the VehCalc vehicle database (snapshot 2026-08-20) for the models listed above. Codes and causes vary by model year and engine.
Diagnostic reference only — not repair advice. This page is provided for educational and planning purposes and does not replace an inspection by a qualified technician or the manufacturer's service information. Before repairing a vehicle you depend on, confirm the diagnosis with an ASE-certified mechanic.