How to Fix a BMW X5 335d Stuck in an AdBlue “0 Starts” Lockout

A notably common problem with BMW X5 335d models is the notorious AdBlue SCR system lockout, where the vehicle readout shows “0 starts remaining” or “No engine start possible”. Unfortunately, once the countdown reaches zero, the vehicle will not start, even if it ran perfectly the last time you parked it. The good news is: it is fixable.

If you are stuck with 0 Starts, don't panic! Our repair price covers this repair. You can simply send your CAS and ECU to us, and we can repair this issue for you and save you thousands of dollars!

So, let’s break down why the BMW X5 335d AdBlue lockout happens, how to diagnose the real cause, and the correct ways to fix it long-term, rather than just resetting it.

What Does “0 Starts Remaining” Mean on a BMW X5 335d?

So, what exactly is happening with this particular error? Well, BMW diesel vehicles that include the SCR (Selective Catalytic Reduction) system were designed (and legally required) to prevent the engine from starting if there are emissions faults present. This most commonly happens when these emissions fault notifications are ignored, and the car will trigger its countdown. You’ll initially get:

• 200 starts remaining
  

• 100 starts remaining
  

• 50 starts remaining
  

• 0 starts remaining, where the vehicle becomes immobilized.
  

Once you reach zero, even adding AdBlue will NOT fix the issue.

What is AdBlue?

AdBlue is a brand name for Diesel Exhaust Fluid (DEF), a colorless liquid made of 32.5% urea and 67.5% deionized water, used in modern diesel vehicles with Selective Catalytic Reduction (SCR) systems to significantly cut harmful nitrogen oxide (NOx) emissions by converting them into harmless nitrogen and water vapor.

Common Causes of BMW X5 335d AdBlue Lockout

Despite what the dashboard message suggests, the problem is often not low AdBlue. The most common causes include:

1. Failed NOx Sensors (Very Common)

• BMW uses upstream and downstream NOx sensors
  

• These sensors frequently fail and falsely report emissions faults
  

• One bad NOx sensor can trigger the entire lockout
  

2. DEF / AdBlue Tank Level Sensor Failure

• The tank may be full, but the sensor reports empty
  

• Common on higher-mileage X5 335d models
  

3. SCR Control Module Faults

• Corrupted data or internal failure
  

• Often caused by voltage issues or water intrusion
  

4. AdBlue Injector or Heater Failure

• Crystallized AdBlue can clog injectors
  

• Heater failure is common in cold climates
  

5. Faults Not Properly Cleared After Repairs

• Even after replacing parts, the lockout remains until reset with BMW-specific diagnostics
  

Step-by-Step: How to Fix BMW X5 335d “0 Starts” Lockout

Step 1: Scan the Vehicle With BMW-Capable Diagnostics

Given the type of fault, OBD scanners are not the right tool to use to scan this component. You need tools that can read SCR and diesel modules, such as:

• ISTA+

• Autel MaxiSys (advanced models)

• Launch X431

The ECU Pro can help read and diagnose your BMW X5 335d problems using professional-grade diagnostic tools. This requires dealer-level or advanced diagnostic software, which The ECU Pro can assist with.

The best solution is to reset the start counter to avoid getting to 0 starts. The ECU Pro can assis with repairing this issue and getting your car's 'no start' issue resolved.

What If the BMW X5 335d Is Already at “0 Starts”?

If the vehicle will not start, it’s best to get in touch with the specialists at The ECU Pro. The professional team can help you with the best diagnostic and decision for your vehicle to ensure you get your car back on the road without breaking the bank.

Why Simply Adding AdBlue Doesn’t Work

While you may think just adding the AdBlue agent would rectify the problem, the issue is a little more complex once the countdown clock has lapsed. 

There is something in the software that causes the processor to lockout and it will not reset even if all the mechanical parts are fixed and correct. When you get to the '0 starts' phase and the ECU locks out, you can send it to The ECU Pro so that we can reset the count and fix the ECU. This all falls under our repair services.

Final Thoughts: Don’t Ignore the Countdown

The BMW X5 335d AdBlue “0 Starts” lockout can be a headache, but can be repaired and avoided in the future. 

If you did get to 0, don't pay thousands of dollars for a new ECU, we can reset the counter and allow the ECU to correctly read the AdBlue levels. 

And you can rest assured, this repair process is not deleting the Adblue system from the ECU, which is illegal in most states. We are resetting the factory software to allow the ECU to start the vehicle again.