About the coil
This is the VAG coil with part number 06E 905 115 E, which we'll just call the Audi coil. Haltech doesn't sell it, but it's easy to source. It's a high-output inductive coil with the igniter built in, designed to sit directly on the spark plug. It was fitted to a wide range of VW and Audi engines and is a favorite for aftermarket coil conversions. Tube lengths vary, so measure your plug well depth before you buy.
Because the igniter is internal, the ECU sends a low-current logic signal straight to each coil. No external igniter is needed.
Haltech settings
| Setting (Elite values) | Use | Why |
|---|---|---|
| Ignition Dwell Mode | Constant Charge | The ECU controls charge time for the internal igniter |
| Ignition Mode | Direct Fire | One coil per cylinder, each on its own output |
| Ignition Edge | Falling | The coil fires as the ECU signal drops |
Direct fire needs a cam signal so the ECU knows which cylinder is on its compression stroke. Haltech has a suggested dwell table for this coil; ask us and we'll send it with advice for your build. Start there and don't add dwell just because you can. See our dwell time article for why.
Wiring
| Coil pin | Connect to |
|---|---|
| 1 | Switched 12V+ |
| 2 | Cylinder head ground |
| 3 | Haltech ignition output for that cylinder |
| 4 | Cylinder head ground |
Both grounds go to the cylinder head. Give them a clean, paint-free point and use a proper ring terminal.
Powering them properly
Each Audi coil can pull close to 10 A. At high RPM and high power, a single 30 A relay feeding a full set can run out of capacity, and the spark suffers. It doesn't happen often, but the fix is to give every pair of coils its own fuse and relay. Wire gauge matters too: undersized feed wires drop voltage under load and weaken the spark just as badly.
Troubleshooting
| Symptom | Usually |
|---|---|
| Misfire only at high RPM and boost | Coil supply voltage sagging: check relay, fuse and wire size |
| No spark on one cylinder | Output wired to the wrong pin, or a poor head ground |
| Coils running hot | Dwell set higher than needed |
Converting a 1.8T AWP? The Nexus plug 'n' play adapter harness for the VW/Audi 1.8T AWP makes the ECU swap simple. For other coil options, compare IGN-1A coils and the Bosch HEC coil.
