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

• Go to “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.

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