The Quick Answer above is the generic definition. What follows is what is documented for the Audi models that log P0670, checked against manufacturer data and owner reports.
DTC/P0670·Audi
P0670 on Audi: Causes, Symptoms and Fix Cost
Quick Answer
Low SeveritySafe to drive (short-term)Audi
P0670 on a Audi is a diesel-only code meaning the engine control unit detected a fault in the glow plug control module circuit. The control module switches high current to the glow plugs that preheat the combustion chambers for cold starting and reports back to the ECU. The code points to the module itself, its supply or control wiring, or its ground rather than to one specific plug. Repairs typically run 70-350 EUR.
Repair cost on Audi€2 - €370
Connect any standard Bluetooth OBD2 adapter to your Audi and Skanyx tells you what P0670 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 P0670 mean on a Audi?
Audi A4 TDI
2004-2019The A4 TDI shares the VAG monitoring control module with the Golf and Passat. P0670 typically points to the module or its connector at higher mileage. The module is often mounted low near the engine where moisture and road salt can corrode the connector, so inspect the plug and pins before condemning the unit.
What causes P0670 on a Audi?
Beyond the generic causes listed on the main P0670 page, these are the documented Audi-specific patterns:
Audi A4 TDIVAG glow plug control module failure
Audi A4 TDIConnector corrosion from moisture and road salt
How to diagnose P0670 on a Audi with OBD2
Follow these steps to pinpoint the root cause of P0670:
- Read the stored code and freeze frame with Skanyx or any ELM327 adapter to confirm P0670 and note the conditions when it set
- Check the fuse feeding the glow plug control module, as a blown fuse can trigger the circuit fault
- Verify battery voltage at the module power supply pin and confirm a clean ground with a multimeter
- Inspect the connector and wiring between the ECU and the control module for corrosion, broken pins, or chafing
- Bench-test the glow plugs themselves with a multimeter (a healthy plug reads roughly 0.5-2 ohm) to rule out a dead plug dragging down the circuit before condemning the module
- Remember that detailed control module and per-plug status is manufacturer-extended (Mode $22) data that generic OBD2 does not expose, so module replacement is confirmed by supply, ground, and wiring checks plus the plug bench test
How much does P0670 cost to fix on a Audi? (EUR)
Estimated repair costs for P0670 in EUR, compiled across makes. Expect Audi parts and labour towards the upper end of each range.
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
Related codes that often appear with P0670 on Audi
These codes commonly cluster with P0670 on Audi vehicles:
Looking for the full P0670 reference (all makes, full diagnosis flow, complete repair cost matrix)?
See the main P0670 guideSkanyx · Audi
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