Here is an interesting story about a parasitic draw on a 2007 VW Jetta.

The customer complaint was about a dead battery if the vehicle sat for more than two days. The vehicle already had a new battery in it when it got here.

We hooked up our low amp probe to the battery cable and verified an unusual parasitic draw that surged up and down between 150 mA and 900 mA.

This draw occurred with the doors,trunk and hood closed and the vehicle locked with the key out of the car. The draw went on continuously, cycling up and down until the battery depleted.

We noticed that when the driver's door was opened, the interior lights did not come on, which they did when any other door was opened. We pinpointed a defective microswitch in the driver's door latch assembly and thought this might cause a parasitic draw.

A new driver's door latch assembly (which contains the microswitch) was installed. Now the interior lights worked properly when the driver's door was opened. The parasitic draw, however, was unchanged.

After a lot of troubleshooting we discovered that disconnecting the driver's door module (integral with the window lift motor) would stop the parasitic draw.

A new driver's door module was ordered, by VIN from the local VW dealer. The new module arrived in a ripped up box with extra shipping labels on it. We installed it anyway and coded it with using Vag-Com with the same coding as the original DDM (Driver's Door Module).

Now the fun starts, since the new module would not allow any of the power windows on the car to work and it also set a trouble code, 01811 for supply voltage low.

Looking closely at the part # on the original DDM showed it to be 1K0-959-701P. The new part # was 1K0-959-701L

We called the VW dealer parts dept. and asked them to verify if this was the correct part. Yes, they assured us, it is the correct part number, only superceded, but maybe its defective.

Another DDM was ordered and arrived two days later. This one was also in a previously opened box with extra shipping labels on it. The part # was identical to the one they had just sent and it did the same as the previous module, which is set code 01811 and not work anything. There was no parasitic draw with the new module, but its hard to call something fixed when no door functions are working.

Now we noticed that the pin arrangement (and there are many pins) on the new module was different than on the original. Some pins on the new module were missing.

I called the dealer and asked them to look into the problem. They then sent me an interesting internal VW bulletin which stated:

"Due to further technical development the latest generation door control units are UDS(Unified Diagnostic Service, a new generation communication protocol) compatible are available for repair. In individual cases, there may be communication problems with the newly fitted door control unit during diagnosis and connection.

Corrective measure: Please install a KWP (Key-Worl Protokoll)/UDS compatible diagnosis interface gateway."

Long story short, they said I would have to install both front door modules with the new "superseded" part numbers, plus install a "gateway module" behind the OBD 11 connector. The parts cost was into 4 figures!

The tech help line at Ross-Tech then drew my attention to a redirect file that showed an incredible 15 different part #s for the driver's door modules!

The best solution,they advised , was to find a used DDM with the exact same part number. Many calls to wrecking yards finally resulted in a match (1K0-959-701P) which when installed and coded, resulted in a door module that worked all door functions and most importantly stopped our parasitic draw. [2007 Volkswagen Jetta 2.5, BATT/Charging/Starting Photo] The first picture shows the original DDM on the left with two new incorrect DDM's sent to me by VW. [2007 Volkswagen Jetta 2.5, Photo] The file picture shows just how many variations there is on this one part.

Hope this helps someone else.

Mark from Ontario

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