Which data we need for your remote diagnosis

The quality of your diagnostic report depends directly on the data you upload.

A single measured value without engine speed, load, temperature and operating state often cannot be assessed reliably in technical terms. In such cases we mark the value as "not assessable" rather than deriving an assumption from it.

The more complete your data are, the more precisely we can narrow down the cause and the more specifically we can name the next test steps.

Please allow around ten minutes for this list. It can save a second read-out session or a later request for more data.

IMPORTANT: Do not clear the fault memory before you have read it out and exported it in full. Clearing it can also destroy freeze frames and further diagnostic information.

1. Vehicle data – required

Please state:

• Vehicle identification number (VIN), 17 characters
• Mileage
• First registration or model year
• Engine code, if known
• Transmission type: manual, automatic or DSG
• Fuel type: petrol, diesel, hybrid, LPG/CNG

2. What you observe on the vehicle – required

Please describe the problem as precisely as possible. More detail is better here than too little.

What exactly happens?

For example:

• Loss of power
• Juddering
• Starting problems
• Limp-home mode
• Unusual noises
• Smoke
• Increased fuel consumption

Since when has the problem existed?

Was there an event immediately beforehand, for example:

• Workshop visit
• Repair
• Refuelling
• Very cold or very hot weather
• Software update
• Battery disconnection

When does the problem occur?

Please state as precisely as possible:

• On cold start
• With the engine at operating temperature
• At idle
• Under part load
• Under full load
• At steady speed
• While accelerating
• On the overrun
• From a certain engine speed onwards
• From a certain road speed onwards

Permanent or sporadic?

If the problem only occurs occasionally: how often?

Warning lights

Which warning lights are active?

Please state whether they:

• Are permanently on
• Flash
• Only appear at times

Work carried out so far

What has already been checked or replaced?

Please also state whether the behaviour changed afterwards.

Fault memory already cleared?

If so:

• When was it cleared?
• Did the fault occur again afterwards?

3. Fault memory – required

Please read out all available control units in full, not just the engine control unit.

Faults in the transmission, ABS, chassis, comfort or other control units can be connected with the symptom you are reporting. There may equally be additional faults that are technically independent of the main problem. We separate these from one another during the analysis.

For each fault we need, wherever possible:

• Fault code
• Standardised P, U, B or C code
• Manufacturer code, if additionally available
• Complete fault text, unchanged as displayed by the diagnostic device
• Status: active/passive or static/sporadic
• Fault frequency counter, if available
• Mileage at the time of the fault entry, if available
• Freeze frame

Especially important: the freeze frame

The freeze frame is among the most important diagnostic data.

It shows, for example:

• Engine speed
• Load
• Temperature
• Vehicle speed
• Voltage supply
• Further operating conditions

at exactly the moment the fault was detected.

This allows us to distinguish far better whether, for instance, we are dealing with an old sporadic fault or a current, reproducible deviation.

4. Data stream / live data – required

Please upload a recording over time wherever possible, not just individual snapshot values.

A single screenshot with one measured value often says very little. A recording of 30–60 seconds under known operating conditions, by contrast, can be highly informative.

Wherever your diagnostic device offers target and actual values, please always record both together.

The difference between the request and the actual measured value is frequently the decisive piece of diagnostic information.

4.1 Basic block – please always record this as well

If available:

• Engine speed
• Engine load / calculated load
• Coolant temperature
• Intake air temperature
• Battery / on-board voltage
• Accelerator pedal position
• Throttle valve position, target
• Throttle valve position, actual

4.2 Operating states

If possible, please document the following four states:

1. Ignition on, engine off – KOEO
approx. 15 seconds

2. Idle at operating temperature
approx. 60 seconds

3. Engine speed ramp while stationary
idle → approx. 2,000 rpm → approx. 3,000 rpm → back to idle

4. Driving under load
steady speed and, if possible, an acceleration during which the reported symptom occurs

Please note briefly for each file which operating state it was recorded in.

Without this assignment even good measurement data lose a considerable part of their value.

5. Additional values related to the symptom

Please also select the area that matches your problem.

Boost pressure / turbocharger

If available:

• Boost pressure, target and actual
• Manifold pressure
• Ambient pressure
• Boost pressure actuator position, target and actual
• Air mass, target and actual

Intake manifold / swirl flaps

• Flap position, target and actual
• Actuation in per cent
• Actuator test, if possible
• During an actuator test, record the request and the position feedback at the same time

Diesel: DPF / particulate filter

• Differential pressure
• Exhaust temperature before the DPF
• Exhaust temperature after the DPF
• Calculated soot load
• Measured soot load, if available
• Kilometres since the last regeneration
• Number of aborted regenerations
• Oil dilution, if output by the control unit

Exhaust gas recirculation / EGR

• EGR rate, target and actual
• EGR valve position, target and actual
• Air mass, target and actual

Diesel fuel system

• Rail pressure, target and actual
• Actuation of the pressure control valve
• Actuation of the metering valve
• Quantity compensation / correction values per cylinder
• Return quantity, if measurable

Petrol fuel system

• High fuel pressure, target and actual
• Low fuel pressure, target and actual
• Lambda sensors before and after the catalytic converter
• Mixture adaptation at idle
• Mixture adaptation under part load
• Additive and multiplicative adaptation values
• Ignition timing retard per cylinder
• Misfire counter per cylinder

SCR / AdBlue

• Fill level
• Quality value, if available
• Metering quantity, target and actual
• NOx value before the SCR catalytic converter
• NOx value after the SCR catalytic converter
• Heating circuits and their actuation
• Enabling conditions of the metering quantity test

Transmission

Please read out the transmission control unit separately and in full.

If available:

• Gear position, target and actual
• Selector lever position
• Transmission oil temperature
• Clutch slip

6. Files and screenshots

Preferred: PDF or CSV export

These formats usually contain more information than individual screenshots.

Please note for screenshots:

• Full screen wherever possible
• Do not crop
• Leave the header with date and time visible
• Do not rename the files if possible

Many diagnostic devices store vehicle, time or session information directly in the file name.

Permitted formats:

• PDF
• JPG
• PNG
• CSV
• TXT

With several recordings, please note briefly which file belongs to which operating state.

7. What not to do

Do not clear the fault memory before it has been read out and exported in full.

Do not type measured values out by hand. Please upload the original export or a complete screenshot.

Do not crop screenshots, not even areas that seem unimportant.

Do not replace parts on suspicion before the diagnosis is complete. Avoiding exactly these unnecessary parts changes is the point of a structured analysis.

Do not send isolated individual values without operating conditions. Without context they cannot be assessed reliably in technical terms.

8. Minimum scope

Not every diagnostic device can supply all the data listed above.

For a meaningful analysis we need at least:

• VIN and mileage
• A precise description of the symptom
• A statement of when the symptom occurs
• The complete fault memory of all reachable control units, including fault status
• Freeze frames for the relevant faults, where available
• A data stream recording at idle with the engine at operating temperature, with the available basic values from section 4.1

In many cases this already allows a reliable narrowing down.

If the data are not sufficient for a clear statement, we tell you specifically which measured values or recordings are still missing.

So you do not receive an apparently clear diagnosis based on insufficient data.

9. Checklist before sending

☐ VIN and mileage stated
☐ Symptom described, with a statement of when it occurs
☐ Fault memory of all reachable control units read out
☐ Fault memory not cleared before the export
☐ Freeze frames saved
☐ Data stream recorded over a period rather than individual values only
☐ Target and actual values recorded together, where available
☐ Operating state documented for every recording
☐ Matching symptom-related additional values from section 5 included
☐ Files uploaded in the original, uncropped and ideally not renamed