The Quick Answer above is the generic definition. What follows is what is documented for the Volkswagen models that log P0670, checked against manufacturer data and owner reports.
DTC/P0670·Volkswagen
P0670 on Volkswagen: Causes, Symptoms and Fix Cost
Quick Answer
Low SeveritySafe to drive (short-term)Volkswagen
P0670 on a Volkswagen 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 Volkswagen€2 - €370
Connect any standard Bluetooth OBD2 adapter to your Volkswagen 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 Volkswagen?
Volkswagen Golf TDI
2005-2021On the Golf TDI the glow plug control module is a smart unit that monitors each plug and reports faults to the ECU. P0670 here is frequently the module itself or its connector, which can corrode. Replacement is straightforward but the part is genuine-VAG priced. Confirm power and ground at the module before ordering one.
What causes P0670 on a Volkswagen?
Beyond the generic causes listed on the main P0670 page, these are the documented Volkswagen-specific patterns:
Volkswagen Golf TDIGlow plug control module failure on TDI engines
Volkswagen Golf TDICorroded module connector triggering a circuit fault
How to diagnose P0670 on a Volkswagen 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 Volkswagen? (EUR)
Estimated repair costs for P0670 in EUR, compiled across makes. Expect Volkswagen 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 Volkswagen
These codes commonly cluster with P0670 on Volkswagen vehicles:
Looking for the full P0670 reference (all makes, full diagnosis flow, complete repair cost matrix)?
See the main P0670 guideSkanyx · Volkswagen
Diagnose P0670 on your Volkswagen
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