Looking for 5 real-world faults to test an application

[nkprl]

Hi everyone,

Over the last few months, we’ve been developing an application designed to help mechanics with vehicle fault diagnosis. Rather than simply saying that it works, we’d like to test it with real-world cases. we’m looking for 5 real vehicle fault cases from different vehicles, preferably cases that are interesting, unusual, or have been difficult to diagnose.

For each case, we would need whatever information is available, such as:
Make / model / year
Engine
fuel type
Fault code(s) DTC if exist
Symptoms
What has already been checked
Any measurements or diagnostic data

I will enter the cases into the application and see what diagnosis and recommended checks it provides. The most important thing for us is to receive honest feedback from people with experience in the field.
If it gets something wrong, I want to know.
If it points in the right direction, I want to know that too.

The goal is not to advertise the application, but to find out how useful such a tool can actually be in a real workshop environment. If anyone would like to participate, simply comment “Interested” or send me a private message. If you have a difficult fault that has been giving you a headache, even better.

No customer personal information or license plates are required.

[Peanut Gallery]

Here is an annoying one I had recently.
Toyota Auris 2014 hybrid.
1.7 petrol + battery.
No error codes.
Occasionally, but with increasing regularity the car would shake.
Changed tyres a few times, and swopped front to back, and balanced.
Brakes serviced lots, then new calipers, discs and pads.
Engine serviced a few times, different plugs, leads, filters, fuel grades.
Gearbox oil changed.
Issue did not show during any test drives, but was still there for the main driver.
Worked out if we get the engine up to temp and kept the revs at the spot where you are cruising the car would surge. Increasing power or decreasing power would change the revs and the surging would stop.
One of the next things would have been to look at the EGR valve, however that is a pain to get to, the car was rusting away badly, owner had dropped far too much money into it but most importantly the owner had lost faith in the car.
(Not helped by 15 hours in the car with a full family and dog and a puncture and their recovery company kept saying "wait with the car" despite being half an hour away from destination)

Problem was solved by selling the car.

[nkprl]

Thanks — this is exactly the kind of intermittent real-world case I want to test.
The application should not treat the EGR as confirmed from the symptom alone. Because it occurs only when fully warm, at a narrow engine-speed/load range, disappears when torque demand changes and has no stored DTC, I would first separate:
1. Engine combustion/airflow/EGR instability.
2. Hybrid torque-control fluctuation.
The first diagnostic step would be a Toyota-capable scan while reproducing the fault, logging misfire counters, engine RPM, vehicle speed, engine torque request/actual, MAF, MAP, A/F or lambda, fuel trims, EGR command/feedback, HV battery SOC/block voltages and MG1/MG2 data.
If hybrid torque changes without misfire, the HSD system becomes more likely. If misfire counters, fuel trims, MAP or EGR feedback change, the investigation should remain focused on the engine/EGR system.
Any Toyota technical bulletin must be checked against the exact VIN/TIS application; a Prius bulletin does not automatically apply to an Auris