ESP – pain in the ass

As I wrote on the previous post, ESP became quite a headache. Actually we drove with the car for almost two years before we were finally forced to get it done because the annual inspection was closing (in Finland you don’t need to do MOT every year for such new cars).

This image says it all – Scirocco’s ABS unit was not happy about the newly installed Haldex controller.

We got fault codes saying we had issues in Powertrain data bus (18055 – Check Coding of ECUs on Powertrain Data Bus). ABS was functioning as it should, just ESP was out of the game. It did not prevent driving, but was obviously a safety issue and MIL light was on. We tried different codings, tried to learn how the coding works. Long Coding helper in VCDS was not very helpful with ABS unit (only a few bits are documented) but we were able to find something by Googling and asking help from Ross-Tech’s forum (Ross-Tech is the maker of VCDS). Eventually we were able to learn what each of the 18 bytes were meaning. Even last five numbers of the VIN were encoded on the coding.

It helped a lot that we had similar Golf R from the same MY so we could compare the coding. Even the ABS unit had exactly the same part no, so we were adamant that there’s a way to code.

So we were trying to generate a code that was similar to Golf R but embedded with VIN digits from Scirocco. Golf was not identical, it had DCC suspension so we still had some bits that we were not sure if they were correct or not. Still, we couldn’t get it done – Coding out of range it was every time.

Many persons from Ross-Tech forums offered help and proposed all kinds of codes, none of those worked. Eventually we realized that the ABS unit communicates with the cluster to learn about the model of the car – when the cluster says the car is a Scirocco, it won’t accept coding as a Golf. And Scirocco can’t be AWD. And vehicle type can’t be changed on the cluster with VCDS.

We found a guy somewhere in Poland who was willing to modify the EEPROM on the cluster but at the same time we decided to try something else. We took the cluster from the donor Golf R and plugged it in Scirocco. The connector is the same.

At least the cluster was working (which was something we expected it to do). Immobilizer kicked in as expected also (Golf cluster and Scirocco ECU won’t work together without tweaking).

Best part was that now ABS unit was happy to clear all the fault codes! Now that the ABS/ESP was handled, we only had two issues remaining: 1. Immobilizer 2. Physical fitment of the Golf cluster. After all the puzzling with the ESP these seemed like minor issues.

We only had one key remaining with Golf so we decided to take it and fit Scirocco’s key blade to the Golf key fob. That way we could keep Scirocco’s original key lock. For cluster-ECU communication there’s two options – take the ECU also from the Golf or disable the Immo from Scirocco’s ECU. Both work well – we decided to keep the Immo and take the ECU from Golf. Now both cluster and ECU were from Golf. Now when someone plugs a tester in the OBD the car seems like a Golf with Golf VIN.

Physical fitment to the cluster was a bit more work. We were comparing the clusters and realized that essentially they are similar, just the outer casing is different. We decided to tear down both and were able to swap the Golf cluster internals inside Scirocco’s cluster casing!

Finally! No fault codes or MIL lights!

There’s only two downsides with the way we did the cluster modification. The 2010 Golf R cluster apparently does not understand automatic long beam headlights. The feature still works, but it just don’t show the symbol that this feature is activated. Sometimes this causes confusion to a person who’s not used to driving with this car.

Another is a bit more unpleasant – you can’t totally deactivate ESP from ESP OFF button. 2010-2011 cars are generation where you can only disable traction control but it still keeps ESP active. This means you can’t have all the 4wd drifting fun on wintertime without taking some ESP fuses off. Apparently they changed this in later models so it might be possible to swap some newer ESP parts in but so far we haven’t done that.

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