clyde
Veteran Member
- Joined
- Apr 8, 2000
- Location
- confluence, Snake/Clearwater
- TDI
- 1998 Jetta, 1959 DeSoto with leopard-skin seat covers
In final stages of TDI conversion (1997 Jetta TDI 1Z engine into 1990 Jetta) I'm considering VAG-COM to get things set correctly.
So I checked the Bentley to see how the Data Link Connector is wired. That's where things got confusing.
According to the Bentley manual the 16-pin DLC connector is wired as follows:
pin 4 Brown ground
pin 5 Brown ground
pin 7 gray-white ABS, Motronic, airbag
pin 15 yellow transmission control module
pin 16 red-white +12 V
While I'm not an engineer, it seems quite strange that a computer program could diagnose what's going on with the electronic controls and the engine from +12V, ground, and airbag signals.
A first guess is that the schematic is a general diagram and that it is mislabeled, and that the pin 7 signal labeled "ABS, Motronic, airbag" (Motronic is an ECU used with a gas engine), actually is the signal from the diesel ECU used with the 1997 Jetta TDI.
If the pin 7 signal is the crucial signal line, it is probably wired appropriately for the TDI control unit.
This car has a manual transmission so its transmission control module is the driver, whose output signals are audio—not electrical via wire…
What I need to know is:
1. Whether I've been testing the right connector (it's black with purple on the exposed end—where another connector would plug in);
2. Whether a VAG-COM will work with only one active signal;
3. Any tests I can make to confirm that the DLC is wired right. It should be—it came from the factory this way; and
4. Anything else to help the newbie find his way out a corner.
Thanks!
So I checked the Bentley to see how the Data Link Connector is wired. That's where things got confusing.
According to the Bentley manual the 16-pin DLC connector is wired as follows:
pin 4 Brown ground
pin 5 Brown ground
pin 7 gray-white ABS, Motronic, airbag
pin 15 yellow transmission control module
pin 16 red-white +12 V
While I'm not an engineer, it seems quite strange that a computer program could diagnose what's going on with the electronic controls and the engine from +12V, ground, and airbag signals.
A first guess is that the schematic is a general diagram and that it is mislabeled, and that the pin 7 signal labeled "ABS, Motronic, airbag" (Motronic is an ECU used with a gas engine), actually is the signal from the diesel ECU used with the 1997 Jetta TDI.
If the pin 7 signal is the crucial signal line, it is probably wired appropriately for the TDI control unit.
This car has a manual transmission so its transmission control module is the driver, whose output signals are audio—not electrical via wire…
What I need to know is:
1. Whether I've been testing the right connector (it's black with purple on the exposed end—where another connector would plug in);
2. Whether a VAG-COM will work with only one active signal;
3. Any tests I can make to confirm that the DLC is wired right. It should be—it came from the factory this way; and
4. Anything else to help the newbie find his way out a corner.
Thanks!