A workshop has a customer present their VE Commodore with an issue, it has all the symptoms of a stretched timing chain, however the chains have been previously replaced by another workshop and there are no fault codes...
This is when I got a call.
I found the incorrectly installed timing chain using ignition test equipment, thermal imaging and in cylinder pressure transducers (pictured). The point isn't whether the vehicle can be diagnosed with or without codes, it's why there were none showing in the first place.
This vehicle had no codes because the engine computer was re-flashed with a software edit, this edit stops it's ability to monitor the Cam-Crank relationship. This means the engine can run terribly (and is) without ever setting a code for correlation. If desired, you can delete nearly any code in an ECM if you know how, but should you?
In the case of the VE, the reason the code was removed was because the workshop that replaced the timing chains made an error. They failed to install the new chains correctly and the engine ran poorly because of this, they then engaged someone to edit the computer to cover up their mistake.
Although this example is a comedy of errors, this raises a bigger question: Should we edit/ modify a vehicles engine computer to work for our personal needs? Most of the time when a code is removed from a computer it is an emissions fault that is being sidelined. The car pollutes the same, but without the fault codes.
The modern internal combustion engine is becoming more and more finely tuned to meet the demands of power, fuel efficiency and emissions standards. If we value the environment, it is important to recognize these cars are manufactured to perform with these systems and it is our job to maintain and repair them.
Comentarii