Electrical Problems - 2002 Jetta TDI

Here are the symptoms:
- Interior lights go on/off randomly
- Alarm goes off when car is unlocked
- Dashboard indicator indicates trunk/door ajar when everything is closed
- Warning bell/buzzer stays on after starting car for at least 3 minutes
- When headlights are turned on, the bell/buzzer goes off
- The trunk will not unlock with the key
- The keyfob does not unlock the doors when pressed

Here is the VAG-COM output:
Sunday,29,June,2008,17:16:39:11973
VCDS Version: Release 805.0
Data version: 20080625



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Chassis Type: 9M - VW Jetta IV
Scan: 01 02 03 08 15 16 17 19 22 29 35 36 37 39 46 47 55 56 57 75
76

VIN: 3VWRP69M02M010715 Mileage: 247110km/153547miles
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Address 01: Engine Labels: 038-906-012-AGR.lbl
Part No: 038 906 012 FD
Component: 1,9l R4 EDC G400AG 4102
Coding: 00001
Shop #: WSC 00066
3VWRP69M02M010715 VWZ7Z0A3836559

2 Faults Found:
16786 - EGR System: Excessive Flow
P0402 - 35-10 - - - Intermittent
17978 - Engine Start Blocked by Immobilizer
P1570 - 35-10 - - - Intermittent
Readiness: 0 1 0 0 0

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Address 02: Auto Trans Labels: 01M-927-733.lbl
Part No: 01M 927 733 KT
Component: AG4 Getriebe 01M 4891
Coding: 00000
Shop #: WSC 00000

No fault code found.

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Address 03: ABS Brakes Labels: 1C0-907-37x-ABS.lbl
Part No: 1C0 907 379 C
Component: ABS FRONT MK60 0103
Coding: 0004097
Shop #: WSC 00066 000 00000

No fault code found.

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Address 15: Airbags Labels: 6Q0-909-605-VW5.lbl
Part No: 6Q0 909 605 F
Component: 04 AIRBAG VW6 0202 0004
Coding: 12340
Shop #: WSC 00066

1 Fault Found:
00532 - Supply Voltage B+
07-10 - Signal too Low - Intermittent

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Address 17: Instruments Labels: 1J0-920-xx5-17.lbl
Part No: 1J0 920 906 M
Component: KOMBI+WEGFAHRSP VDO V58
Coding: 07232
Shop #: WSC 00000
3VWRP69M02M010715 VWZ7Z0A3836559

2 Faults Found:
01176 - Key
07-10 - Signal too Low - Intermittent
01336 - Data Bus for Comfort System
49-10 - No Communications - Intermittent

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Address 19: CAN Gateway Labels: 6N0-909-901.lbl
Part No: 6N0 909 901
Component: Gateway K<->CAN 0001
Coding: 00006
Shop #: WSC 00066

1 Fault Found:
01336 - Data Bus for Comfort System
49-10 - No Communications - Intermittent

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Address 35: Centr. Locks Labels:
Note: Excessive Comm Errors


End ---------------------------------------------------------------------


Clearly from the VAG-COM it looks like the central locks controller has a problem. Any ideas? I hate to replace it without diagnosing further. Any idea where the central locks controller is physically located? If I knew where it was I could check the external connections for loose connections, loose wires, etc.

Any help would be appreciated. Thanks.

-Jeff

It is approximately behind/below the tachometer. Pull fuse 14, wait a few seconds, plug it back in. Clear fault codes.

You may also have a bad microswitch in one or more door latches.

It also looks like possibly somebody disconnected the battery at some time with the key in the on position.

MOGolf said:

It is approximately behind/below the tachometer.

Click to expand...

What does it look like? Will it be obvious? Any distinguishing features? Is it accessable from the floor area under the steering wheel, or do I have to pull the instrument cluster out to get at it?

MOGolf said:

Pull fuse 14, wait a few seconds, plug it back in. Clear fault codes.

Click to expand...

Why? Is this just to get a new baseline (erase old codes), or will this reset something that might fix the problem?

MOGolf said:

You may also have a bad microswitch in one or more door latches.

Click to expand...

What gives you this idea?

MOGolf said:

It also looks like possibly somebody disconnected the battery at some time with the key in the on position.

Click to expand...

What gives you this indication?


Sorry for the dumb questions here - just trying to learn as much as I can. Thanks.

-Jeff

this sounds like the microswitch to the door to me.

If the car thinks the door is always open you will have a lot of those behaviors.

If you look you will find that there is a $3 fix using a microswitch from radioshack.

I also found with mine that it was the tracer on the circuit board in the lock that was bad. I soldered on a wire jumping from the microswitch contacts to the contacts for the connector and it fixed the problem. My switch was failed closed so it was less of a problem than one that was failed open.

LowHanger said:

What does it look like? Will it be obvious? Any distinguishing features? Is it accessable from the floor area under the steering wheel, or do I have to pull the instrument cluster out to get at it?

Click to expand...

It's a black box. The best way to get at it is to remove the trim panels under the steering wheel (in front of your knees as you sit in the seat), and the steel panel behind it (you have to remove the panel underneath (above where your feet would be) too.

Why? Is this just to get a new baseline (erase old codes), or will this reset something that might fix the problem?

Click to expand...

It "reboots" the control module.

What gives you this idea?

Click to expand...

It reads like all the things that happen when you open the driver's door (e.g. interior lights going on).

What gives you this indication?

Click to expand...

Supply voltage fault in ABS controller and "signal too low" faults.