P0673 on Audi: Causes, Symptoms and Fix Cost
Quick Answer
Safe to drive (short-term)
P0673 on a Audi is a diesel-only code meaning the engine control unit detected an electrical fault in the glow plug circuit for cylinder 3. Glow plugs preheat each combustion chamber so a cold diesel can ignite. The code identifies the cylinder 3 circuit specifically, usually pointing to a failed plug, its wiring, or its connection rather than the whole system. Repairs typically run 30-180 EUR for a single plug and circuit fix.
- Severity
- Moderate · Electrical
- Typical repair cost, all makes
- €5-€420
Connect a standard OBD2 adapter (Bluetooth LE on iPhone) to your Audi and Skanyx tells you what P0673 means on that engine, whether it is safe to keep driving, and what the fix should cost. Free on iPhone and Android.
Get Skanyx freeWhat does P0673 mean on a Audi?
The Quick Answer above is the generic definition. What follows is the model-specific detail for the Audi models that log P0673.
Audi A4 TDI
2004-2019
The A4 TDI uses the same VAG per-plug monitoring as the Golf, so P0673 isolates cylinder 3. Some 2.0 and 3.0 TDI engines use fragile ceramic glow plugs that can snap if removed cold, so warm removal is essential. Replacing one plug is inexpensive unless a ceramic plug breaks off in the head.
What causes P0673 on a Audi?
Beyond the generic causes listed on the main P0673 page, these are the patterns noted for Audi models:
Failed cylinder 3 plug on VAG TDI engines
: Audi A4 TDI
Fragile ceramic plug snapping on some 2.0/3.0 TDI
: Audi A4 TDI
How to diagnose P0673 on a Audi with OBD2
- Read the stored code and freeze frame with Skanyx or any ELM327 adapter to confirm P0673 and note the start temperature when it set
- Locate the cylinder 3 glow plug and inspect its connector and wiring for corrosion, looseness, or damage
- Disconnect the cylinder 3 glow plug and bench-test it with a multimeter: a healthy plug reads roughly 0.5-2 ohm, while an open (infinite) reading confirms that plug has failed
- If the cylinder 3 plug is good, check continuity of its wiring back to the control module and verify a clean ground
- Remember that per-cylinder glow plug live status is manufacturer-extended (Mode $22) data, not generic OBD2, so the multimeter test on the cylinder 3 plug is how you confirm the failure
- Consider replacing the full set if the plugs are original and high-mileage, since the others are likely to fail soon
How much does P0673 cost to fix on a Audi? (EUR)
Estimated repair costs for P0673 in EUR, compiled across makes. Expect Audi parts and labour towards the upper end of each range.
| Repair | Parts Cost | Labor Cost | Total Estimate | DIY Difficulty |
|---|---|---|---|---|
| Replace cylinder 3 glow plug (DIY) | €10–€30 | €0–€0 | €10–€30 | Moderate |
| Repair cylinder 3 connector/wiring (DIY) | €5–€25 | €0–€0 | €5–€25 | Moderate |
| Replace cylinder 3 glow plug (shop) | €10–€30 | €40–€120 | €50–€150 | Moderate |
| Replace full glow plug set as preventive (shop) | €60–€200 | €90–€220 | €150–€420 | Professional |
Prices estimated as of October 2026. Costs vary by region, vehicle, and shop.
Codes related to P0673
These codes are often seen alongside P0673 or point to related issues, on any make:
Looking for the full P0673 reference (all makes, full diagnosis flow, complete repair cost matrix)? See the main P0673 guide