A few weeks ago we had a VW beetle 1.6 petrol come into the workshop. It had a couple of issues, the engine management light was on and so was the traction control light but the ABS light was off. After scanning with the FCAR F3W we ascertained the fault with the traction control was with the ,lateral acceleration sensor, and the engine fault was due to a secondary air system malfunction.
We quickly sorted the engine fault, it was just the vacuum pipe going to the valve on the manifold, a quick and easy fix. The traction fault was next,
we had looked at the live data from the sensor and decided the problem was either the unit itself or the wiring, the values were way off what they were supposed to be, according to Ross Tech the correct settings should be +- 1.5 ms , this one was reading +7.8
Now this is where things got strange, after removing the plug to the sensor (the acceleration sensor is easy enough to get to, it is mounted to the steering column, you need to remove the panel above the pedals to access the sensor) and checking and cleaning the wiring, once it was all assembled again once we switched on the ignition, the ABS was on with the stability light, we rescanned the module but now the module coding had disappeared!
Of course as we were not interested in coding or doing any other tests than reading the faults and viewing the live data, this was a bomb from out of the blue. We did not have the original soft coding and as this was a MK 20 system so there was no info to figure out what the coding was. After a lot of searching I finally found a site that had soft coding for the MK20 module. After entering 40168 to allow the login we then matched the ECU type and information with the list below and we were able to successfully recode the module. Here is a list of the modules and their coding:
A very useful piece of information.