I had this Touareg in today with a complaint of transmission won't shift. I found it unable to shift out of Park because the interlock was inop.; after manually releasing it I went for a drive and the trans. would not shift out of first gear.

A code scan found lots of communication codes, and no scanner communication with several modules including the TCM, ABS, AWD, etc. Scope testing the data bus lines at the DLC showed no communication signal on pins 2 and 6, and no B+ at pin 1. After looking at a schematic I checked fuse B51 (serves DLC pin 1) and found no voltage at the fuse, also no voltage at fuses B47, 49, 50, 52, 53 & 54. These fuses serve the various modules that were offline, and all are powered by the J239 Power Supply relay, located in the fuse box under the driver's seat. Testing there, the relay had B+ on both sides, but was not being grounded by the Access/Start control module (under the dash, LH side). No voltage was present at the module, so I followed the harness and found the culprit under the driver's carpet. There are several splices in this harness with no weather protection other than an electrical tape wrap and all were green with corrosion, including the J239 relay control circuit. I cut them all out, replaced and heat shrunk them, and the issue was solved. Two of the splices were in the middle of a single circuit with only two wires being joined together, so I'm not sure about the wisdom of having a splice there.

[2004 Volkswagen Touareg V6, Photo] [2004 Volkswagen Touareg V6, Photo]

Scott Sauvola
Technician
Ace Auto, Inc.
Winona, Minnesota, USA

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