Stay ahead of the curve with the latest Technical Service Bulletins (TSBs) added in the past month.
DDTSB is growing again – this time with 209 brand-new TSBs and 122 updates, all based on real hotline cases and real-world diagnostics from workshops across Europe.

Below are three strong and technically relevant examples from the newest uploads.

Example 1. VAG Bosch 3 Pin Common Rail Injector With NCC

Vehicles affected

This fault pattern is seen on VAG diesel vehicles from around 2020 to 2026 fitted with:

• EA288 EVO diesel engines
• EA897 Gen 3 diesel engines
• Bosch 3 pin common rail solenoid injectors with Needle Closing Control, NCC

Although this injector type was introduced earlier, many aftermarket workshops are only now starting to see these vehicles with higher mileage. According to our Hotline, this technology is still new to many technicians in daily workshop diagnosis.

Common symptoms

A faulty Bosch 3 pin common rail injector with NCC can cause several driveability and emissions related symptoms, including:

• MIL on
• Uneven idle or rough running
• Intermittent injector malfunction
• Injector deviation values changing suddenly
• Failed DPF regeneration
• Extended crank time on first start-up
• One or more injector circuit fault codes

Common fault codes include:

• P020100, Injector Circuit cylinder 1
• P020200, Injector Circuit cylinder 2
• P020300, Injector Circuit cylinder 3
• P020400, Injector Circuit cylinder 4

Why this injector is different

At first glance, the fault may look like a normal injector circuit problem. But this injector is not a standard 2 pin solenoid injector.

The Bosch NCC injector is still operated by a solenoid valve, but it also has a piezo sensor built into the injector body. This sensor detects when the injector needle actually closes, and the ECU uses that feedback to correct injection timing and injection duration while the engine is running.

A normal solenoid injector usually has 2 pins. This injector has 3 pins:

• Pin 1 and pin 3 are used for the solenoid side of the injector
• Pin 2 is used for the needle closing feedback signal to the ECU

This makes it a closed-loop common rail solenoid injector with integrated needle-closing feedback.

Depending on operating conditions, these injectors can perform up to 9 injections per operating cycle. Up to 3 pilot injections can be used for smooth running, and during DPF regeneration up to 5 post injections may be used.

Underlying cause of problems

The common failure is an intermittent internal electrical fault inside the injector.

The fault can be in the solenoid side, but it can also be inside the piezo feedback sensor. If the feedback signal is incorrect, the ECU receives wrong information about the needle closing event and may adjust the injection duration in the wrong direction.

This can result in rough idle, injector deviation spikes, injector circuit fault codes, long crank time and DPF regeneration problems.

Why diagnosis can be difficult

The fault can come and go. Injector deviation values may be outside the limit one moment and normal the next.

The fault code may say injector circuit, but it does not tell you whether the problem is caused by the solenoid side, the wiring, the ECU control or the internal feedback sensor.

That is why this injector should not be tested like a normal 2-pin injector only.

Practical diagnostic approach

The first step is to recognise the injector type by checking the connector.

If it has 3 pins, the feedback circuit must be included in the diagnosis. This is where many normal injector test routines are not enough.

In DDTSB No. 13341, we explain the function of the Bosch NCC injector and show how the fault can be confirmed with real workshop measurements.

The bulletin includes scan tool values, deviation examples, resistance checks, PicoScope measurements and feedback signal examples during ignition on, idle and wide open throttle.

The point is not just to replace the injector because a P020 code is stored.

The point is to compare the suspect injector against a known good pattern and make a safer decision before replacing parts.

Example 2. Mercedes Benz ML, GL and GLE Class 166 SAM Diagnosis

Vehicle and Symptoms

Mercedes Benz ML, GL and GLE Class 166 from 2012 to 2019.

• The engine will not start.
• Some lights may illuminate even when the ignition is not switched on.
• The vehicle can also have many communication faults stored.

Typical fault codes are:

B21F200. Status Terminal 15 is unlikely.
B229D97. The control unit has a malfunction. System functionality is limited.
C14100. Communication with the front signal detection and activation module has malfunctioned.
C42700. Improbable data was received from the electronic ignition switch.
U010000. Communication with the engine control unit has malfunctioned.

There can also be a long list of extra U codes stored in different control units.

Initial Thoughts

It is always a tough decision to condemn a control module. It is even harder when the suspected module is a SAM. The SAM is not just a simple fuse box. It is part of the supply control, relay activation and communication network. So before replacing a SAM, the diagnosis has to be solid.

This fault can easily push you in the wrong direction. The symptoms can look very similar to a faulty ignition switch (N73), and that is already a known common issue on these vehicles.

The scan report can also look very long. There can be fault codes for engine ECU communication, transmission communication, ESP communication, ignition lock communication, Parktronic, air conditioning, instrument cluster, steering column module and more. It usually means a large part of the car is missing the voltage supply it needs.

System Overview

The important components in this case are:

Electronic ignition switch N73.
Front central electronics SAM N10.
Main fuse box F33 under the passenger seat.
Integrated relay K1 inside fuse box F33.
Cabin fuse box F32 slash 4 in front of the passenger seat.

The problem is that SAM N10 can fail in a way where it no longer activates relay K1 in fuse box F33.

Relay K1 is a double relay. It supplies fuses in the F33 fuse box.

When this relay is not activated, a large part of the vehicle loses power supply. Then the vehicle stores many communication faults and the engine may not start.

Challenges in Diagnosis

The first challenge is the amount of fault codes.

A full scan can make it look like half the car has failed. That is where you need to stop and look for the common cause.

Another challenge is understanding the process between N73, relay K1, SAM N10 and fuse box F33. If you are not familiar with Mercedes, you can easily go through 30 to 35 pages of wiring information just to understand the supply path.

That has now been boiled down into DDTSB No. 13478.

Practical Solution

This is the part where guessing must stop.

Before replacing the SAM N10, the supply path has to be proven step by step. The fault pattern can look like a bad ignition switch, a relay issue, a CAN problem or a dead module, depending on which fault codes you focus on first.

In DDTSB No. 13478, the diagnosis is boiled down to a practical measurement procedure.

The test route follows the logic between the ignition switch N73, SAM N10, relay K1 and fuse box F33.

The goal is simple.

Confirm if the SAM has what it needs.

Confirm if the relay side reacts correctly.

Confirm where the voltage supply stops.

Confirm the CAN and power supply condition before any module is condemned.

This makes the decision to replace the SAM much safer. You are not replacing it because the scan report looks bad. You are replacing it because the measurement procedure confirms that it can no longer activate the supply path correctly.

After replacement, the SAM must be coded and programmed as required.

The complete step by step test procedure is available in DDTSB No. 13478.

Example 3. Renault Twingo III No Start and No ECU Communication

Vehicle and Symptoms

Renault Twingo III from 2014 to 2019 with 1.0 TCe H4D 400 engine.

• The engine has stalled and will not start again.
• The starter motor is not activated.
• The MIL flashes.
• There is no diagnostic communication with the ECU.

Initial Thoughts

When a vehicle will not start and the tester cannot communicate, the normal diagnostic routine is blocked right away.

• No scan report.
• No fault code direction.
• No quick overview of which modules are online.

You have to start with the basics. Power supply, grounds and communication.

After some time in the diagnostic process, you may find that the engine control unit is missing a 12 volt supply. That gives you a direction.

But then the next challenge appears.

If fuse F05 is blown, it does not only supply one component. It supplies 6 components in total. In theory, any one of these components or wiring branches can be the reason why the fuse has blown.

That is where this type of case can take several hours in the workshop.

Challenges in Diagnosis

The first challenge is that there may be no fault codes available.

The tester cannot communicate with the vehicle, so you cannot search the fault by DTC.

The second challenge is that the fault can be intermittent.

The vehicle may fail once, then work again later. This makes it easy to lose the fault while testing.

The third challenge is fuse F05.

When a fuse supplies several components, the fuse itself is only the result. It is not the diagnosis.

You still need to know which component or circuit is the most likely cause, and how to isolate the fault in the right order.

Why This TSB Matters

This is exactly the kind of case where a symptom based TSB saves time.

The technician may find the missing 12 volt supply, but the next question is which component or wiring branch is pulling fuse F05 down.

In DDTSB No. 13333, the diagnostic path is based on a real workshop case and boiled down into a practical test direction.

The point is not just to replace the fuse.

The point is to find why the fuse failed and isolate the fault without wasting hours.

How to Find This Bulletin in the Portal

This case may not be easy to find by fault code, because fault code reading may not be possible.

In that situation, use the predefined symptom search in the DDTSB portal.

Select the symptom:

Engine. Starting problems.

With that symptom selected, this type of TSB information will appear in the program.

DDTSB number. 13333.

Want more real life cases?

If you enjoy stories like these and want to see the work that goes on behind the scenes at DDTSB, make sure to subscribe to our new YouTube channel. There we share more case stories, diagnostic tips and repair insights straight from the workshop floor.

https://www.youtube.com/@DDTSB

🚀 Maximize Your Workshop’s Potential with DDTSB

Gain access to:

Thousands of exclusive aftermarket TSBs

Real-world fixes from one of Europe’s largest hotline centers

Faster diagnostics, smarter repairs, and higher profitability

⏱️Time is money. Save both with  DDTSB

Follow us on:

Het bericht Newly Uploaded TSBs – April/May 2026 verscheen eerst op DiagnoseDan.

Example 1:

TSB No. 11908 – Intermittent Gearbox Faults in Multi-brand Vans (KO Platform)

Relevant models:

Citroën Jumpy IV / Spacetourer (K0)
Fiat Scudo/Ulysse (KO)
Opel/Vauxhall Vivaro-C/Zafira Life (KO)
Peugeot Expert IV/Traveller (KO)
Toyota Proace/Proace Verso

Symptoms:

• MIL warning light

• Intermittent fault message on the transmission system

• Fault codes include:

  • P0977 15 – Solenoid SC3: Short to positive/open circuit

  • P0980 15 – Solenoid SC4: Short to positive/open circuit

  • P099C 15 – Lock Solenoid Valve: Short to positive/open circuit

Initial thoughts – from the mind of a technician:

Alright, so the MIL is on and I’ve got those solenoid fault codes stored. First thing that pops into my head? Let’s head straight for the mechatronic unit. I’m thinking: “Could be a classic case of a bad connection or voltage drop.”

So I grab the wiring diagrams, get the multimeter out, and start checking the positive side of the solenoids — especially under load conditions. I’m paying close attention to any signs of low voltage or even an open circuit. Everything checks out clean in the workshop. But then… I take it for a test drive, and boom — the fault shows up again.

Now I’m scratching my head. “Alright… could this be the internal electric valves in the transmission starting to fail?” That would be the next logical step.

But then I pause — and remind myself: “Wait, better double-check DDTSB first before going down the rabbit hole.” That’s when the real diagnostic path starts to shift.

• Select the car by licence plate / VIN or manual search.
• Go to Bulletins.
• Enter the fault code.

With that in mind, your focus now shifts to the ground connection shown in the TSB — even though the fault codes don’t point directly to any issues on the negative side. When faults are intermittent, this is where a wiggle test or a voltage drop test under load can reveal the real culprit.

We have seen this a fair amount of times in our Hotline and thanks to the kind feedback from several workshops we are convinced that this will be a very common issue and therefore a good aftermarket TSB.

Example 2:

TSB No. 11935 – Critical Maintenance Alert: Transfer Case Oil on Mercedes GLE (167)

Relevant Model:

• Mercedes-Benz GLE (W167)

Symptoms of Incorrect Maintenance:

• Post-service vibrations, chugging, or jerking in the driveline

• Damage to the transfer case

• Unclear oil specification, even from dealerships

This is one of those underrated features in DDTSB that many new users simply overlook. And honestly? It can be a real lifesaver, especially when you’re about to do routine maintenance on a car you haven’t worked on before.

Think about it — maybe it’s a standard oil change, a gearbox flush, or you’re replacing the transfer case oil on a model that’s new to your workshop. You’ve got your tools laid out, fluids ready, and you’re good to go. But spending just 30 seconds in DDTSB before you start can save you hours of frustration down the road.

Why? Because these maintenance bulletins are based on real questions from the field — the kind of stuff we technicians call into the Hotline about every single day. It’s where you find those sneaky “technician traps” — the mistakes we all fall into at some point, especially when we’re in a rush or unfamiliar with the system.

So before you even touch the car:

• Select the vehicle — via license plate, VIN, or manual search

• Aller à “Bulletins”

• Select the category: “Maintenance”

When you search in DDTSB, Critical bulletins are always listed at the top — and we strongly recommend checking these before you start any job. If there’s a common mistake that catches technicians out on what seems like a routine task, this is where we raise the flag. We call them “Technician Traps”, and TSB No. 11935 is a textbook example.

Take the transfer case on the Mercedes GLE — even dealership techs can get unsure about which oil it actually needs. Call a dealer and ask — chances are, you’ll get a few minutes of silence while they dig for the answer. That’s because the correct oil type depends on the exact setup: transmission type, engine variant, 4MATIC or not, production date… it all plays a role.

And that’s exactly why we highlight this in DDTSB — to make you aware of the potential pitfall before you grab the wrong fluid. It’s one of those easy-to-miss details that can cause vibrations, chugging, or premature wear. Worst case? You’ve got a damaged transfer case on your hands and a very expensive warranty discussion to go through.

Here’s an example of how the oil type information is actually made available:

In the OEM literature — or in tools like Alldata — there’s usually a direct link to the correct oil spec. That way, if the manufacturer decides to change or update the specification, they only need to do it in one place.

Example link:
https://operatingfluids.mercedes-benz.com/sheet/239.41/de

It’s a clever system from the manufacturer’s side — but for us in the aftermarket, it can be a nightmare to keep track of, especially in older printed oil catalogs or static databases.

We know this can easily catch workshops out. Even if you’ve got access to DDTSB, if you forget to check the Maintenance section, it’s something you might find out too late — usually when the car comes back with vibrations or chugging from the driveline, a few weeks or months after a service.

By that point, it’s too late. And if it ends up being a warranty case, you’ll be expected to prove that the correct spec was used — right there on the invoice. If not, and the car needs a new transfer case, you’re looking at a very costly lesson.

Example 3:

TSB No. 11763 – Ford Ranger 3.2 TDCi (2015–2022): Intermittent Engine Stall and a Hidden 5V Supply Trap

Symptoms:

Engine intermittently dies or will not start. One/more fault codes stored:
P0237 – Turbo/Super Charger Boost Sensor A Circuit Low
P02E8 – Diesel Intake Air Flow Position Sensor Circuit Low
P0405 – Exhaust Gas Recirculation Sensor A Circuit Low
P0642 – Sensor Reference Voltage “A” Circuit Low
P1874 – Transmission Automatic Hall Effect Sensor Power Circuit Failure
P2122 – Throttle/Pedal Position Sens/Switch D Circ Low Input
P2229 – Barometric Pressure Circ High
P2454 – Particulate Matter Trap Differential Pressure Sensor Circuit Low

Travel of Thought – as a technician:
You see that long list of fault codes, and your first instinct is: “Alright, something’s going on with the 5V reference.” Especially when you see multiple unrelated sensors acting up at the same time — that usually means a shared supply voltage issue.

Depending on how many of those DTCs are stored, you might even start hunting for a shorted sensor that’s dragging the 5V line down for the rest. That’s a logical direction, and a lot of us would head there first.

But this is where the job gets tricky.

The fault is intermittent — it might run fine one moment and die the next. And here’s the part that really throws you off: the actual culprit isn’t one of the sensors at all… it’s the cooling fan.

Yep, that’s the last thing you’d expect to be on a shared 5V supply, but in this case, it is.

TSB No. 11763 points you toward a specific wire harness — small, easy to overlook, but it’s where the issue starts. Whether it’s damaged insulation, a short to ground, or high resistance on the supply line, this little harness is the one you want to check first.

Practical tip:
Start your diagnosis not at the sensors, but at the cooling fan harness. Wiggle test it, measure the voltage drop under load, and you might just save yourself hours of unnecessary digging.

Maximize your workshop’s potential with DDTSB! Access thousands of exclusive aftermarket TSBs, diagnose faster, repair smarter, and increase profitability. Time is money—save both with  DDTSB

Het bericht Newly uploaded TSBs Feb. + March 2025 verscheen eerst op DiagnoseDan.