When you’re facing issues with your Volkswagen Passat’s OBD2 port, one of the first and simplest things to check is the fuse. A blown fuse can easily cut power to your OBD2 port, preventing you from running diagnostics or using any devices that connect through it. This guide will pinpoint the exact fuse for your Passat’s OBD2 port and provide a helpful fuse list for MKIV models.
Identifying the OBD2 Port Fuse in Your Passat
For the MKIV generation Volkswagen Passat, the fuse responsible for powering the Data Link Connector (DLC), commonly known as the OBD2 port, is fuse number 12.
This fuse is located in the top section of your Passat’s fuse box. It’s a 7.5 Amp fuse. If you’re experiencing problems with your OBD2 port, such as a scanner not powering on or failing to communicate with your vehicle’s computer, checking and potentially replacing this fuse should be your initial step.
Even if the fuse appears to be visually intact, it’s always a good idea to replace it with a new 7.5 Amp fuse. Sometimes fuses can have hairline fractures that are not easily visible, leading to intermittent or complete failure. A simple fuse replacement can often resolve OBD2 port issues quickly and inexpensively.
Complete MKIV Fuse List for Volkswagen Passat
To further assist you in understanding your Passat’s fuse system, here is a comprehensive list of fuses for the MKIV generation. This list is organized to mirror the layout of the fuse box for easy identification.
Top Section Fuses (Left to Right, Column by Column)
- Washer nozzle heaters, glove compartment light, memory seat control module (10A).
- Turn signal lights (10A).
- Fog light relay, instrument panel light dimmer switch (5A).
- License plate light (5A).
- Comfort system, cruise control, Climatronic, A/C, heated seat control modules, automatic day/night interior mirror, control module for multi-function steering wheel, control unit in steering wheel (7.5A).
- Central locking system (5A).
- Back-up lights, speedometer vehicle speed sensor (VSS) (10A).
- Open
- Anti-lock brake system (ABS) (5A).
- Engine control module (ECM): gasoline engine (10A); diesel engine, Model Year 2000 > (5A).
- Instrument cluster, shift lock solenoid (5A).
- Data Link Connector (DLC) power supply (7.5A). (This is your OBD2 port fuse)
- Brake tail lights (10A).
- Interior lights, central locking system (10A).
- Instrument cluster, transmission control module (TCM) (5A).
- A/C clutch, after-run coolant pump (10A).
- Open.
- Headlight high beam, right (10A).
- Headlight high beam, left (10A).
- Headlight low beam, right (15A).
- Headlight low beam, left (15A).
- Parking lights right, side marker right (5A).
- Parking lights left, side marker left (5A).
Bottom Section Fuses (Left to Right, Column by Column)
- Windshield and rear window washer pump, windshield wiper motor (20A).
- Fresh air blower, Climatronic, A/C (25A).
- Rear window defogger (25A).
- Motor for rear windshield wiper (15A).
- Fuel pump (FP) (15A).
- Engine control module (ECM) gasoline engine (15A); diesel engine (10A).
- Power sunroof control module (20A).
- Transmission control module (TCM) (20A).
- Injectors: gasoline engine (10A); diesel engine (15A).
- Headlight washer system (20A).
- Open
- Engine control elements (10A).
- 12 V power outlet (in luggage compartment) (30A).
- Fog lights (15A).
- Terminal (86S) on radio, Instrument cluster (10A).
- Central locking system (with power windows), luggage compartment light, remote/fuel tank door, motor to unlock rear lid (15A).
- Emergency flashers (15A).
- Dual tone horn (20A).
- Cigarette lighter (15A).
- Radio (25A).
- Engine control elements (10A).
- Heated seats (15A).
Fuse Arrangements in Fuse Bracket/Battery
- S162. Glow plugs (coolant) (50A).
- S163. Fuel pump (FP) relay/glow plug relay (50A).
- S164. Coolant fan control (FC) control module/coolant fan (40A).
- S176. Relays panel interior (110A).
- S177. Generator (GEN) (90 Amp.) (110A). Generator (GEN) (120 Amp.) (150A).
- S178. ABS (hydraulic pumps) (30A).
- S179. ABS (30A).
- S180. Coolant fan (30A).
Conclusion
If you are troubleshooting your Passat’s OBD2 port, remember to check fuse #12 first. This simple check and potential fuse replacement can save you time and money. Having access to a complete fuse list like this can be invaluable for any MKIV Volkswagen Passat owner for general maintenance and electrical troubleshooting.
