Ignition Ground Harness Kit with Hardware and Terminal Tool

Our Ignition Ground Harness Kit is designed by DAP (Deutsche Auto Parts) for Volkswagen and Audi 1.8T and 2.0T Gen 3 and Gen 4 engines. It replaces the four individual ignition coil ground wires with one harness and includes the hardware and terminal tool needed for factory looking installation.

On the factory setup, each ignition coil has its own ground wire with a metal eyelet.  This is attached to a ground stud at each ignition coil. Because a special thin wrench is required to properly remove them, these eyelets are often damaged during service work.  

All four grounds are combined into one harness with a single ground point located on the passenger side of the valve cover. New hardware is included to finish the installation.

What’s included with your Harness Kit 

• Ground harness (connector varies by selection) 

• M6 x 1.0 x 45 mm bolts 

• Ignition terminal tool

Why These Grounds Fail

• Damaged or broken ground eyelets (installation errors)

• Stripped threads in the valve cover (installation errors)

• Aged or brittle ground wires

How to Tell If Your Grounds Have Failed

A problem with the ignition ground can be tricky to diagnose because the symptoms can look a lot like a bad ignition coil. Before replacing another coil, it is worth checking the grounds and connectors.

Some common symptoms include:

• Misfire that comes and goes or moves between cylinders

• Rough or uneven idle

• Stumble or hesitation during acceleration

• Check engine light with random or cylinder-specific misfire codes

• Replacing an ignition coil without resolving the misfire

Checking the grounds is fairly simple. Remove the engine cover and inspect the ground connection at each ignition coil. Look for bent or cracked eyelets, damaged wires, or anything that does not look like it is sitting flat and secure. Check the fastener as well. If it turns without tightening, the threads may be stripped.

This is also a good opportunity to inspect the ignition coil connectors. Look for broken locking tabs or other damage and make sure each connector locks securely onto the coil. When properly installed, the connector should click into place and stay firmly attached.

Which Connector Do You Have, 4D0 or 8K0?

The VIN will not be helpful in identifying your connector style.  You are going to have to physically check the connector yourself to verify which style you have.

While you have the connector unplugged, take a look at its condition. If the locking tab is broken or the housing is cracked, it is a good idea to replace the connector while everything is already apart. We stock both styles individually:

Ignition Coil Electrical Connector 4D0971994

Ignition Coil Electrical Connector 8K0971994

The terminal tool is an important part and included in the kit. A small screwdriver or pick may seem like it will work, but it is easy to damage the connector in the process.

Installation Tools

• 10 MM Flat Wrench for MQB Ignition Coil Nut (or needle nose pliers)

• 10 MM regular wrench

• Ignition terminal tool (included)

• Pocket flathead screwdriver

• Pick 

• 10 MM deep socket with rachet

• T30 Torx

Installation

This is a DIY- friendly job. If this is your first time removing the coils, give yourself an afternoon. Work on a cold engine. It is also a good idea to take a few photos before removing anything, especially the wire colors and their positions if you are replacing the connectors too.

Getting the Old Grounds Out

1. Remove the engine cover

2. Take the ground nut off at each coil, while holding the bolt with the thin 10mm flat wrench or needle nose

3. Unplug each ignition coil connector

4. Open the wiring conduit

5. Pull the purple lock tab out of each connector

6. Release each ground wire from terminal with the included terminal tool

Putting the New Harness In

1. Lay DAP ground harness in conduit and ensure each wire and terminal end lines up with an ignition coil connector.  Ensure the eyelet is facing down and lays flat under the coolant pipe on the drivers side of the valve cover.

2. Insert each new terminal into the position the old ground wire came out of

3. Listen for the click, then tug the wire to confirm it is seated

4. Reinstall the purple secondary locks

5. Fit the ground eyelet under the coolant pipe and tighten (10nm)

6. Install and tighten the new M6 bolts at each coil (10nm)

7. Reinstall the engine cover, reconnect the battery, start the car and check for misfires

If you still have a misfire check the following:

• You may have an alternate cause of misfire (ie Ignition Coils, Spark Plugs, Fuel Injectors, etc)

• Ignition coil connectors are fully seated and locked

• Ground terminals are fully seated in the connectors

• Spark plugs are properly installed

• Ground eyelets are making good metal-to-metal contact

• Ground bolts are tight

DIY Guides

Fixing MK7/MK8 2.0T Ground Wires Forever - Video DAP

How to Replace an Ignition Coil Connector - Video DAP w Humble Mechanic

Fitment

This kit is not compatible with the 1.4T engine

Audi

• A3 8V

• A3 8Y

• TT / TT-S MK3

Volkswagen

• Arteon 2019 to current

• Atlas 2018 to current

• Beetle 2012 to 2017

• Passat B7

• Tiguan 2018 to current

• MK6 Jetta and Jetta GLI

• MK7 GTI / Golf / Golf R

• MK7 Jetta GLI

• MK7 Sportwagen / Alltrack

• MK7.5 GTI / Golf / Golf R

• MK8 GTI / Golf R

Why DAP

Designed by DAP. We developed this kit to eliminate the easily damaged factory ground eyelets and make future spark plug and ignition coil service easier. 

Installation videos. We filmed the installation on an actual car so you can see the process before you start.

Everything you need to do the job. We stock both ignition coil connector styles, along with coils, spark plugs, and the tools needed for the job.

Related Parts

Genuine OE Spark Plug for 1.8T / 2.0T EA888.3

Genuine OE Spark Plug for 2.0T EA888.4